--- Log opened Mon Mar 17 12:20:15 2014 12:20 -!- matches [matches@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 12:20 -!- Irssi: #ipdf: Total of 2 nicks [1 ops, 0 halfops, 0 voices, 1 normal] 12:20 -!- Irssi: Join to #ipdf was synced in 0 secs 12:20 -!- sulix changed the topic of #ipdf to: Angry Strawberry Summer 12:20 -!- mode/#ipdf [+o matches] by sulix 12:39 <@sulix> This is sensible discussion about the project. 12:39 <@matches> The suspense 12:39 <@sulix> Anyone up for lunch? 12:39 <@matches> Yes 12:40 <@sulix> drumroll... 12:41 <@matches> I don't think it worked 12:42 <@matches> Yes I did it manually 12:42 <@matches> Maybe cron is broken on motsugo 12:43 <@sulix> We shall find out next time at 12:40, I guess. 12:43 <@sulix> (Or the next time cron emails errors out, maybe) 12:52 <@matches> Let the record show that it didn't work because I didn't install the crontab --- Day changed Wed Mar 19 2014 10:59 <@matches> Some guy asked me if he could use the whiteboard, so I let him rub out our timeline 10:59 <@matches> And all he did was write "hello world" 10:59 <@matches> >:( 19:10 <@matches> Testing 19:25 <@matches> So the IRC commits should have a different author 19:25 <@matches> So that I don't get a ridiculous number of daily IRC commits 19:26 <@matches> I could rebase the first three of them but I think that might break things 19:45 <@matches> Ok, and now it will only commit when there is more than one new line, so we won't get one every day when no one says anything 19:54 <@matches> Alright, and in theory 19:54 <@matches> If I spam this some more 19:54 <@matches> There will be a commit soonish 19:56 <@matches> Any second... 19:56 <@matches> Yes 19:56 <@matches> Now that is sorted out I can attain maximum productivity 19:56 <@matches> (Sorry) --- Log closed Mon Mar 24 01:12:25 2014 --- Log opened Mon Mar 24 08:40:12 2014 08:40 -!- matches [matches@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 08:40 -!- Irssi: #ipdf: Total of 2 nicks [1 ops, 0 halfops, 0 voices, 1 normal] 08:40 -!- Irssi: Join to #ipdf was synced in 3 secs 13:26 -!- Netsplit arctic.uniirc.com <-> mussel.ucc.au.uniirc.com quits: @sulix 13:27 < matches> Uh oh 13:29 -!- Netsplit over, joins: @sulix 13:31 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 13:32 -!- Netsplit over, joins: @sulix 13:40 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 13:40 -!- Netsplit over, joins: @sulix 16:19 < matches> Well that will make a nice automatic commit --- Day changed Tue Mar 25 2014 21:33 < matches> So, I am pretty much free all day tomorrow 21:33 < matches> Also Thursday 21:34 <@sulix> I'm pretty busy Thursday, but I'm free all tomorrow so long as I can get some maths done at some point. 21:34 -!- mode/#ipdf [+o matches] by sulix 21:35 <@matches> I'm supervising a test from 2-3pm but that's it 21:35 <@matches> So, I will try and get to UWA as early as I can 21:35 <@matches> It might be a good idea to have some kind of start on a code base 21:35 <@matches> Even though we're supposed to be focusing on a literature review, I don't really like not having any code done yet 21:36 <@sulix> Yeah. I agree. 21:36 <@sulix> Code + fixing git stuff + preparing for this "talk" on Friday. --- Day changed Wed Mar 26 2014 11:32 <@matches> I am in the super secret room 11:36 <@sulix> Okay, I'll head in shortly. Had a small "parents fell for a scam email and entered passwords on dodgy websites" crisis here this morning. 11:37 <@matches> Oh dear 11:42 <@matches> The phone is ringing :O 11:43 <@matches> Phew, it stopped 22:42 <@matches> I think I have a way to do tests in the Makefile without using cmake 22:42 <@matches> You can alter a variable for a target 23:20 <@matches> Well, that ended badly 23:21 <@matches> With me erasing my own Makefile using make 23:21 <@matches> :P 23:24 <@sulix> Better than erasing the source code, I guess. 23:34 <@matches> This is why we have git --- Day changed Thu Mar 27 2014 00:15 <@sulix> Crazy templated loading and saving! 00:15 <@sulix> And now for bed! 00:30 <@matches> Well 00:30 <@matches> It doesn't break the test 01:22 <@matches> We now have an arbitrary precision float 01:22 <@matches> Where in this case arbitrary precision means I have no idea what the precision is but it is very bad 01:35 <@matches> Ok I think I made a half precision float 01:35 <@matches> They are quite bad 01:36 <@matches> Um, I can probably make a graph of it being terrible as my contribution for Friday 01:36 <@matches> Assuming I've done it right --- Day changed Wed Apr 02 2014 09:41 <@matches> Dammit codejam is coming up again 09:41 <@matches> There goes productivity 09:42 <@matches> If you are not busy this afternoon we should do work 09:42 <@matches> On the project I mean 09:45 <@matches> Although it is tempting to just practice codejam problems for the next week 12:44 <@matches> If I work on the project it will help when the inevitable "64 bits is not enough" problem comes up! 12:45 <@matches> Maybe --- Day changed Sun Apr 06 2014 13:40 <@matches> I get the feeling my part of the project could just be "typedef Real to something from boost" 14:15 <@matches> I suppose I could talk about FPU and hardware --- Day changed Mon Apr 07 2014 21:42 <@matches> I had a horrible horrible thought... implement a FPU in VHDL and then somehow run all our floating point operations on it :P 21:42 <@matches> (This is not a good idea at all but it might be fun) 21:42 <@matches> You know, for some definition of fun 21:44 <@matches> So my lit review will probably be 1) We need higher precision documents because science (Pixels or Perish) 2) This is how FP works in hardware 3) This is how you can get higher precision in software 21:45 <@matches> Oh, and 4) Document formats and rendering them (PDF/PostScript etc) 21:46 <@matches> That is starting to sound suitably ridiculously broad? 21:46 <@matches> Can always cut things out I guess 21:47 <@matches> To reflect what we actually end up doing 22:05 <@sulix> From what Tim was saying, I don't think "too broad" is a possibility. 22:05 <@sulix> We could be talking about Aztec history and it'd probably not be "too broad." 22:05 <@sulix> I do need to remember to read "Pixels of Perish," though. 22:19 <@matches> I'll have a look into VHDL stuff, there seem to be compilers and simulators for linux 22:20 <@matches> For a minute I was afraid I'd have to use the UWA EE VHDL environment 22:20 <@matches> Which is like, running a Java program in a Windows XP VM 22:20 <@matches> I heard you liked simulations of hardware so I simulated some hardware in your simulated hardware --- Day changed Tue Apr 08 2014 10:46 -!- Netsplit arctic.uniirc.com <-> mits.mits.au.uniirc.com, services.uniirc.com, irc.cassa.au.uniirc.com, mussel.ucc.au.uniirc.com quits: @sulix 10:46 -!- Netsplit over, joins: @sulix 11:31 <@matches> The "Experiment Running" sign seems to have worked 11:31 <@matches> Also open source VHDL stuff is less "actually compiles" than I had hoped 11:32 <@matches> The two I've tried so far seem to generate absolute monstrosities of C or C++ files and then fail to compile and/or link --- Day changed Wed Apr 09 2014 15:27 <@sulix> So I've been hitting my head against my desk for about half an hour trying to work out where some bugs were in some ipdf code I'm writing. 15:27 <@sulix> Turns out to have mostly been precision issues due to the lack of precision in your Real data type. 15:28 <@sulix> Switching it to double fixes them all. 15:32 <@matches> Oh 15:32 <@matches> Sorry 15:37 <@sulix> Nah: it's good. It means that precision actually is important! 15:37 <@sulix> (I was getting a little bit concerned for a while :P) 15:40 <@matches> Well 15:40 <@matches> I have rediscovered just how awful VHDL is 15:41 <@matches> It seems like you can't define anything without typing it three times 15:42 <@matches> You define an entity 15:42 <@matches> Then you define a component with identical ports 15:42 <@matches> Then you tell it to use the entity for that component 15:42 <@matches> Then you tell it to map the identical ports to the entity ports 15:42 <@matches> adder_0 : adder port map (a=>a, b=>b, cin=>cin, s=>s, cout=>cout); 15:44 <@matches> Pretty much all the hardware papers I found talk about using VHDL for things 15:46 <@matches> Let's see if I can make any sense of this jop-devel thing that appears to be a JVM implemented in VHDL 15:47 <@matches> Uh oh, .bat files 15:48 <@matches> This looks ominous 15:51 <@sulix> The whole swapping out main thing breaks the makefile in a few ways btw. 15:51 <@sulix> Because none of main.cpp's dependencies are listed. 15:51 <@matches> Ah 15:51 <@sulix> So if you change main.h, nothing gets recompiled. 16:02 <@sulix> Okay, just pushed support for click+drag and zoom in and out in the viewer. 16:03 <@sulix> (I did change the default precision to single, rather than half, as zoom out was totally broken with half-precision) 16:05 <@matches> The half precision implementation is broken itself anyway 16:07 <@matches> Hmm 16:07 <@matches> I can't seem to compile anymore 16:07 <@matches> Hang on 16:07 <@matches> That would be because `uname -i` reports "unknown" 16:12 <@matches> I have made unknown default to x86_64 :S 16:13 <@matches> I can see the precision issues! Good work 16:14 <@matches> These lecture notes seem useful: http://www.cs.berkeley.edu/~demmel/cs267/lecture21/lecture21.html 16:14 <@matches> Lecture notes > Blog post in terms of suitable reference? 16:16 <@sulix> It's got fortran in it, it must be suitably acedemic. 16:18 <@matches> Haha 16:18 <@matches> The VHDL compiler I am experimenting with uses Ada 16:18 <@sulix> I'm getting my fill of new languages by trying out some c++11 features. 16:20 <@sulix> I think I broak realtofloat by changing things to be single precision by default. 16:22 <@sulix> (Hopefully fixed) 16:49 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 16:49 -!- Netsplit over, joins: @sulix 16:54 <@matches> What's with the netsplits 16:55 <@matches> You're on mussel? I'm on mantis? They are VMs on the same host? 16:55 <@matches> I don't know what this uniirc nonsense is 16:56 <@matches> What is "arctic" 16:56 -!- matches changed the topic of #ipdf to: Happy Bannana Netsplit 17:33 <@matches> Well I compiled the VHDL FPU 17:33 <@matches> It seems to work quite well 17:33 <@matches> Except for the part where it never actually finishes an operation 17:34 <@matches> One of the virtual transistors must have overheated 17:43 <@matches> Oops it might help to actually give it a valid operation 18:27 <@matches> Alright, so I'm going to experiment with getting our Real operations to run on the virtual FPU 18:28 <@matches> Then I can look into both hardware and software ways of getting arbitrary precision. 18:30 <@matches> VHDL appears to have text I/O so I could make everything read and write from pipes, but this seems like a terrible idea 18:30 <@matches> On the other hand the compiler is using Ada 19:21 <@matches> Oh wow 19:21 <@matches> To open stdout 19:22 <@matches> You pass it a string "STD_OUTPUT" for the filename 21:40 <@matches> Ok, I give up trying to link this thing 21:40 <@matches> fork() and exec() is seeming more and more elegant 22:11 <@matches> Nooo, buffering 22:11 <@matches> Ok, screw this --- Day changed Thu Apr 10 2014 00:00 <@matches> Note: Actually exec'ing the program instead of just going straight to "exit(EXIT_FAILURE)" is generally important 00:00 <@matches> Wall of text commit message incoming 00:01 <@matches> Horribly inefficient interface to virtual FPU sort of implemented 00:02 <@matches> I would have made it based on binary read/write rather than hex strings but I could not work out how to do that in VHDL 00:08 <@matches> I still can't believe what I have just done, it seems ludicrous 00:08 <@matches> Using an entire executable and stdio operations 00:08 <@matches> To do a floating point addition 00:10 <@matches> You should see how much is involved in compiling the VHDL FPU... 00:11 <@matches> I'm very pleased that it actually compiled from the version in jop's github without much effort, but still 00:11 <@matches> It's like 30 object files 00:11 <@matches> This is why it isn't in the code repo 00:19 <@matches> Whoops, there are some blatantly wrong comments in vfpu.cpp 00:19 <@matches> Oh well --- Day changed Fri Apr 11 2014 13:38 <@matches> Warning! I am about to make a ipdf/vfpu repo 13:43 <@matches> You know what's really cool 13:43 <@matches> You can run it as `vfpu --vcd=output.vcd` 13:43 <@matches> And it will create a gtkwave file as it runs showing all the operations 13:44 <@matches> You only get the simulated time from the point of view of the device 13:44 <@matches> Which is probably useful 13:46 <@matches> Or it would be if I wanted to compare different devices 13:47 <@matches> To do that I need to actually make different devices... 17:12 <@matches> Would you prefer seperate repos for the individual reports or just sub directories in the documents repo? 17:12 <@matches> I can't decide 17:12 <@matches> On the one hand 5+ repos is getting a bit out of hand 17:12 <@matches> On the other hand they are individual work 17:24 <@matches> Individual seems best 20:31 <@matches> Hmm 20:31 <@matches> The sqrt op in the fpu appears to have been commented out 20:31 <@matches> Also despite having constants for the sizes of things they have just used magic numbers everywhere 20:34 <@matches> I need an IRC script to prevent myself from saying stuff unless someone else has said things, or this channel will just be me ranting --- Day changed Mon Apr 14 2014 13:42 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 13:43 -!- Netsplit over, joins: @sulix 14:42 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 14:43 -!- Netsplit over, joins: @sulix 18:32 -!- Netsplit arctic.uniirc.com <-> mussel.ucc.au.uniirc.com quits: @sulix 18:32 -!- Netsplit over, joins: @sulix 18:34 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 18:35 -!- Netsplit over, joins: @sulix 18:36 -!- Netsplit arctic.uniirc.com <-> mussel.ucc.au.uniirc.com quits: @sulix 18:38 -!- Netsplit over, joins: @sulix 18:40 -!- Netsplit arctic.uniirc.com <-> mussel.ucc.au.uniirc.com quits: @sulix 18:41 -!- Netsplit over, joins: @sulix 18:41 -!- Netsplit mantis.ucc.au.uniirc.com <-> 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joined #ipdf 19:35 -!- ServerMode/#ipdf [+o sulix] by mussel.ucc.au.uniirc.com 19:40 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 19:42 -!- Netsplit over, joins: @sulix 19:44 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 19:48 -!- sulix [sulix@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 19:48 -!- ServerMode/#ipdf [+o sulix] by mussel.ucc.au.uniirc.com 19:54 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 19:54 -!- Netsplit over, joins: @sulix 19:54 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 19:54 -!- Netsplit over, joins: @sulix 19:55 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 19:56 -!- You're now known as 13VAAAAGJ 19:56 -!- Netsplit over, joins: @sulix 19:57 <@13VAAAAGJ> Why am I now known as 13VAAAAGJ 19:57 <@13VAAAAGJ> WHAT THE FUCK IS GOING ON 19:57 <@13VAAAAGJ> ARE WE UNDER ATTACK 19:57 <@13VAAAAGJ> Oh crap this is #ipdf 19:57 <@13VAAAAGJ> Um, disregard this bit of the totally project related conversation 19:57 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 19:57 <@13VAAAAGJ> I'd edit the commit script to censor the swear words, but effort 19:57 <@13VAAAAGJ> Oh dear 19:57 -!- Netsplit over, joins: @sulix 19:57 <@13VAAAAGJ> Hello 19:58 <@13VAAAAGJ> I think mantis might be dying? 19:59 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 20:00 -!- Netsplit over, joins: @sulix 20:01 -!- Netsplit arctic.uniirc.com <-> mussel.ucc.au.uniirc.com quits: @sulix 20:01 -!- Netsplit over, joins: @sulix 20:04 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 20:04 -!- Netsplit over, joins: @sulix 20:05 <@13VAAAAGJ> Sigh 20:07 -!- Netsplit arctic.uniirc.com <-> mussel.ucc.au.uniirc.com quits: @sulix 20:07 -!- Netsplit over, joins: @sulix 20:08 -!- Netsplit arctic.uniirc.com <-> mussel.ucc.au.uniirc.com quits: @sulix 20:08 -!- Netsplit over, joins: @sulix 20:08 -!- Netsplit mantis.ucc.au.uniirc.com <-> arctic.uniirc.com quits: @sulix 20:09 -!- Netsplit over, joins: @sulix 20:09 -!- Netsplit arctic.uniirc.com <-> mussel.ucc.au.uniirc.com quits: @sulix 20:10 -!- Netsplit over, joins: @sulix --- Log closed Mon Apr 14 20:11:29 2014 --- Log opened Mon Apr 14 20:18:05 2014 20:18 -!- matches [matches@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 20:18 -!- Irssi: #ipdf: Total of 2 nicks [1 ops, 0 halfops, 0 voices, 1 normal] 20:18 -!- Irssi: Join to #ipdf was synced in 0 secs 22:04 < matches> Ergh 22:06 < matches> http://szmoore.net/ghdl.bug 22:06 < matches> Pretty 22:10 < matches> Looks like we'll be sticking with ASCII input files for the FPU --- Log closed Mon Apr 14 22:29:33 2014 --- Log opened Mon Apr 14 22:44:34 2014 22:44 -!- matches [matches@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 22:44 -!- Irssi: #ipdf: Total of 1 nicks [1 ops, 0 halfops, 0 voices, 0 normal] 22:44 -!- sulix [sulix@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 22:44 -!- Irssi: Join to #ipdf was synced in 12 secs 22:53 <@matches> Someone's VPS was compromised and killing our network 22:53 <@matches> For reference 22:53 <@matches> It affects this project because 23:07 <@matches> Argh 23:07 <@matches> So I thought I was being really clever 23:07 <@matches> I had files of type "bit" and everything 23:07 <@matches> Guess how a "bit" is represented... 23:08 <@matches> It's an ASCII "0" or "1" 23:09 <@matches> I guess I will just conclude that ASCII strings treated as hex is the only way --- Day changed Wed Apr 16 2014 00:10 <@matches> I'm either about to perpetrate horrible things on your nice View class or give up and go to sleep 00:28 <@matches> Yeah... the problem is if we want to overlay objects rendered using different precision's over each other 00:28 <@matches> It leads towards templates 00:29 <@matches> And templates lead towards fear 00:29 <@matches> And fear leads towards anger 00:29 <@matches> And anger leads to hate 00:29 <@matches> I think 00:29 <@matches> Saving an image 00:29 <@matches> Recompiling the program 00:29 <@matches> Overlaying the image 00:29 <@matches> Is going to lead to less hate 00:30 <@matches> Otherwise pretty much every occurance of "Real" needs to be come a template 00:50 < sulix> So there are a couple of problems with doing that. 00:51 < sulix> - You'd need some way of storing objects of different precision. Possibly an extra "high-precision bounds" struct. 00:51 < sulix> - View also uses real for its internal bounds, which is where many of the problems appear. 00:52 < sulix> (I guess you could have a "high-precision viewport" as well.) 00:52 < sulix> - The actual upload of graphics data to OpenGL is done as 32-bit floats, no matter the type of real, as that's all OpenGL supports. 00:53 < sulix> (At some point we'll have to actually do some view transforms on the CPU rather than just passing all of the bounds and viewport straight to OpenGL) 01:02 <@matches> Yeah I don't want to replace Real with templates 01:02 <@matches> That'd be horrible 01:03 <@matches> By the way, the introduction of SDL_Renderer in SDL2 is confusing 01:05 <@matches> I thought it was replacing Surface with Renderer and Texture 01:05 <@matches> But Surface seems to still be a thing 01:13 < sulix> Yeah: basically Surfaces are in CPU memory, textures in GPU memory. 01:13 <@matches> Right 01:14 <@matches> And renderers magically put stuff on surfaces/textures 01:14 < sulix> Yeah. 01:14 < sulix> So it basically represents the graphics card. 01:15 < sulix> But if you want to just use OpenGL yourself, you don't need to create a renderer at all. 01:15 <@matches> Ah, but the plot thickens 01:15 <@matches> I'm saving the window to a bmp 01:16 <@matches> Which requires a renderer 01:16 < sulix> Hmm... I'm not sure if that will work. 01:16 <@matches> It does 01:16 <@matches> It seems rather convoluted though to be honest 01:16 < sulix> (In theory, it shouldn't, but it probably actually does) 01:16 <@matches> I seem to remember it not being this convoluted in SDL1.2 01:16 <@matches> -_- 01:16 <@matches> So the procedure is 01:17 <@matches> 1. Get a surface associated with the window 01:17 <@matches> 2. Allocate buffer of unsigned char for the pixels 01:17 < sulix> Yeah, TBH I prefer SDL1.2's rendering API, but I generally just use OpenGL anyway. 01:17 <@matches> 3. Get renderer from the window (NB: Don't use SDL_CreateRenderer, only the (undocumented) SDL_GetRenderer works because the Window already has a Renderer because it has been created with an OpenGL flag)... 01:18 < sulix> In theory we should probably use glReadPixels. 01:18 <@matches> 4. Use the magical renderer power to put pixels into the pixel array 01:18 <@matches> 5. Create an RGB surface from the pixel array 01:18 <@matches> 6. Now you can call SDL_SaveBMP, congratulations 01:18 <@matches> What's this about a glReadPixels 01:18 <@matches> I was just about to commit this 01:19 < sulix> Well, you can use glReadPixels instead of steps 1,3 and 4. 01:19 < sulix> (This is what SDL is doing behind the scenes) 01:20 < sulix> Unfortunately, the SDL wiki is still down thanks to heartbleed. :/ 01:20 <@matches> :O 01:20 <@matches> It was up when I looked at it before 01:20 <@matches> Throwing python exceptions when I tried the search function though 01:21 < sulix> Ryan said that it was up, but I'm still getting revoked certificate errors. 01:22 <@matches> Hmm, I needed to do step 1 in order to know the size of the pixel array in step 2... 01:23 < sulix> Screen::ViewportWidth(), Screen::ViewportHeight() 01:26 <@matches> Yeah this is looking a lot shorter than what I had 01:33 <@matches> It doesn't seem to work though 01:35 <@matches> I'm getting a segfault 01:35 <@matches> And of course valgrind automatically exits when it gets more than 1000000 errors from the flgrx driver 01:38 <@matches> First call to glReadPixels is OK but the bmp is just white, second call segfaults 01:39 < sulix> Hmm... what's the call? 01:44 <@matches> Segfault was due to me forgetting about the pixels needing 4 bytes for RGBA 01:44 <@matches> Still white though 01:45 < sulix> (That was going to be my guess) 01:45 <@matches> The advantage of getting the SDL_Surface 01:45 <@matches> Was that you just pass all the surf->format->format->stuff 01:45 <@matches> Everywhere 01:45 <@matches> Also makes it rather verbose 01:46 < sulix> The white screen might just be an fglrx bug. 01:46 <@matches> There we go 01:47 <@matches> No, it helps to remember that the pixels need 4 bytes for RGBA 01:47 <@matches> I have very selective memory 01:47 <@matches> I had to remember it for each line individually 01:47 <@matches> Right I guess it is slightly nicer now 01:47 <@matches> Although it has a bunch of magical "*4" everywhere 01:48 <@matches> I'm going to put this on Stack overflow as an alternative to the answer I was originally following 01:48 < sulix> Well, I'm going to attempt to sleep... 01:48 <@matches> Thank you for fixing my bug without seeing it :S 01:49 < sulix> I have far too much experience breaking glReadPixels... 01:53 <@matches> We need an easy way to compare our document rendering the same thing using a different Real and/or view representation 01:53 <@matches> Templates would only solve changing the Real and really they probably wouldn't actually solve it 01:53 <@matches> They'd just create nightmares 01:53 <@matches> Hmm 01:55 <@matches> Um 01:55 <@matches> Just looking at View::Render 01:55 <@matches> Why is there a seperate loop for each type of object... 01:56 <@matches> With "continue" statements for the other types in each loop 01:56 <@matches> Is this so you can just make one call to glBegin and glEnd... 01:56 <@matches> I am suitable scared 01:57 <@matches> suitably scared and also suitable scared 22:05 <@matches> Ok, trying again. This is the sort of thing a template is supposed to be used for... I just seem to always end up suddenly having to make everything all the way back to Document into a template class :S 22:07 <@matches> blergh 22:07 <@matches> trying again 22:07 <@matches> After getting coffee 22:07 <@matches> I think 22:30 <@matches> Ok, templates is way too complicated 22:30 <@matches> I am going to do the following instead: 22:31 <@matches> 1. Allow a "save this region to bmp" argument 22:31 <@matches> 2. It reads the specified bmp, saves a new bmp with the current view overlayed in a different colour or something 22:32 <@matches> 3. Makefile hacks to recompile the program using a different typedef of Real and then do 1. and 2. for them all 22:32 <@matches> 4. Realise I probably should have used templates 23:02 <@matches> So, according to my timeline that I haven't looked at since submitting the proposal, I will have done a draft literature review by tomorrow... 23:02 <@matches> Hah --- Day changed Thu Apr 17 2014 00:26 <@matches> I am not good at OpenGL/SDL 00:26 <@matches> I am the master of producing a black screen 00:26 <@matches> Also we have FILLED and OUTLINE the wrong way round still 14:01 < sulix> Bunch of bugfixes incoming. 14:01 < sulix> I'm not proud of what I did to glReadPixels, but it works. 14:02 <@matches> Uh oh 14:02 <@matches> I just worked it out! 14:03 <@matches> The dreaded merge begins 14:03 <@matches> I'm tempted to just delete my changes and merge yours but I should probably do a real merge 14:04 <@matches> I fixed it (on my machine at least) by: Using GL_BGRA instead of GL_RGBA (should probably detect which one to use from the screen's format) 14:04 <@matches> And calling glReadBuffers and glPixelStorei before glReadPixels 14:05 < sulix> glPixelStorei is probably nicer than what I'm doing. 14:05 < sulix> I tried just giving SDL a negative pitch and a pointer to the bottom-right corner of the buffer, but somehow it didn't like that much. 14:07 <@matches> You do actually check the byte order which is good 14:08 <@matches> I worked that out but basically just changed it to match my machine :S 14:08 < sulix> There are a bunch of endian problems in the load-save code anyway if we want it to run on big-endian machines. 14:09 < sulix> (Well, big-endian documents don't load with little-endian code and vice-versa) 14:10 <@matches> http://szmoore.net/ipdf/code/src/screen.cpp 14:10 <@matches> Is the merge 14:10 <@matches> Which one is better? 14:11 < sulix> I think yours will still get the bitmaps upside down? 14:11 <@matches> Ah yes they do tend to be upside down 14:12 < sulix> I'm not sure you should need the front buffer stuff anymore with mine, so if you just keep mine (which is doing the flipping), everything should work. 14:12 <@matches> Woah you fixed the FILLED vs OUTLINE 14:12 < sulix> I did test overlaying bitmaps and it was fine. 14:12 <@matches> Good 14:12 <@matches> Does this seem like a better way to compare approaches than using a template and having View View etc? 14:13 <@matches> It means recompiling 14:13 <@matches> But it means a lot less templates 14:13 <@matches> Pretty much the entire thing has to be templatified that way 14:13 <@matches> And then there's the issue of what type the document is saving with 14:13 < sulix> I think, long term, it'd be worth just extending the view to have a "bounds" and a "high_precision_bounds" or something. 14:14 < sulix> But that is kind-of ugly. 14:14 <@matches> I think it's probably nicer to just have real.h contain nothing but a typedef 14:14 <@matches> And just recompile with a different typedef and overlay the images 14:15 < sulix> Yeah, but there are some artefacts that really show better in motion, so it's probably worth supporting that at some point. 14:15 <@matches> True 14:15 <@matches> But including a video in the pdf will be difficult anyway 14:16 < sulix> (Clearly, we should add embedded videos to ipdf) 14:16 <@matches> You could also make a movie using ffmpeg 14:16 <@matches> Haha 14:16 < sulix> (I've got some OpenGL video playback code somewhere...) 14:17 <@matches> In fact, if you can output a video you can just overlay two videos 14:17 < sulix> Oh... my... god! 14:17 <@matches> I don't know if there's a better way to make a video but I'd just be saving a .bmp every frame and then combine them all with fmpeg 14:17 < sulix> Nope, that's probably a good way. 14:18 < sulix> With some MAGIC it wouldn't even be slow. 14:20 <@matches> Whoops your code isn't giving me a second bmp anymore 14:20 <@matches> At least, not one that has pixels that aren't white 14:20 <@matches> Does my glReadBuffer thing work for you? 14:21 < sulix> Hmm... 14:21 <@matches> Can fix the upside-downness some other way 14:21 < sulix> Did you make clean 14:21 < sulix> Because main.cpp/main.h won't recompile otherwise. 14:21 < sulix> And I moved the glClear() calls. 14:22 <@matches> I did make clean 14:22 < sulix> Which is a less hacky way of solving the problem than reading the front buffer. 14:23 <@matches> So the problem is that the texture rendered by Screen::RenderBMP isn't in the buffer that glReadPixels reads from? 14:23 <@matches> (Even though it gets shown on the screen fine) 14:25 < sulix> Hmm... it works fine here with or without glReadBuffers. 14:27 < sulix> Try changing it to save the screenshot before calling scr.Present() in main.h 14:29 <@matches> That works 14:29 <@matches> But why? 14:29 < sulix> Because when you call Present(), it allocates a new buffer to render into. 14:30 <@matches> Right 14:30 < sulix> This is so that you can start rendering the new frame immediately, rather than having to wait for the window manager to actually re-render the screen. 14:31 <@matches> I have merged it 14:33 < sulix> Excellent. 14:33 < sulix> This is much more fun than literature! 14:33 <@matches> :S 14:35 <@matches> It's important 14:35 <@matches> It's part of the timeline 14:35 <@matches> Just you know 14:35 <@matches> It comes after the Literature Review 14:37 < sulix> Strictly speaking the Lit Review deadline is past, now, isn't it... :/ 14:38 <@matches> Well technically it was never a deadline for me... :P 14:38 * sulix sighs 14:38 < sulix> I'm special. 14:39 <@matches> I need to read that last paper on FPUs more 14:39 <@matches> It was talking about how there are all these software techniques from the 1960s that can actually be done on the FPU itself 14:40 <@matches> I'll probably just work on getting our / jop's FPU working for different sized floats instead 14:40 <@matches> In theory that will teach me how they actually work 14:40 <@matches> Then I can actually understand the papers 14:40 < sulix> But can you write about it in a Lit Review? 14:42 <@matches> Maybe not so much the Lit Review, but it means I can write the Background section that explains how they work 14:43 <@matches> There's probably some early papers on them that I can reference at the same time if I try hard enough to find them 14:44 <@matches> The modern papers all have a lot of assumed knowledge 15:59 <@matches> Instead of reading papers I have progressed towards compiling different types and then overlaying them 16:02 <@matches> I didn't know you could do such cool things with Makefiles and flags to the compiler 16:02 <@matches> If people knew more about this maybe we wouldn't have to have python 16:03 <@matches> I will learn to do all my highlevel programming using Make 19:48 <@matches> Our Render/Screenshot combo for overlaying bitmaps and $$$ only works the first time it is done 19:49 <@matches> Or maybe it's RenderBMP that only works once 19:49 <@matches> Hmm 19:52 <@matches> I swear the format was BGRA earlier and now it's RGBA 19:53 <@matches> This can probably get fixed after some Literature Review 20:09 <@matches> Anyway you can now set the type of Real with `make DEF=-DREAL=X` 20:09 <@matches> Or `make single` and `make double` 20:09 <@matches> 0 and 1 respectively 20:09 <@matches> I tried a little bit too hard to get it working with actual C strings 21:32 <@matches> Minutes now have less "~*" in them 21:32 <@matches> Wrong channel 21:32 <@matches> Very wrong channel --- Day changed Mon Apr 21 2014 12:32 <@matches> Literature Review O'Clock 12:36 < sulix> I have just returned from my Easter holiday and have some horrible code for you to scream at while I have lunch. :P 12:43 <@matches> Uh oh 12:44 <@matches> stb_truetype ? 12:44 <@matches> DejaVuSansMono.ttf ?! 12:44 <@matches> Is this going to render a font... 12:45 <@matches> Woah 12:47 <@matches> Looks good 12:48 <@matches> I think I will avoid looking at stb_truetype too closely... 12:48 <@matches> Too late 12:48 <@matches> Why are all the implementations in the .h file 12:48 <@matches> And the .cpp file just has some defines... 12:48 <@matches> shudder 12:53 <@matches> I particularly like #define STBTT_assert(...) do {} while(0) 12:53 < sulix> That's a standard way of doing that. SDL_assert does the same thing. 12:54 < sulix> It lets you put a semicolon after it or use it in an if() statement without braces, etc, without things breaking horribly. 12:56 <@matches> But... your assert doesn't actually assert anything? 12:56 < sulix> That's because you generally only want it enabled in debug builds. 12:56 <@matches> I guess 12:57 < sulix> So typically you'd have it as do {} while(0) in release builds, and something like a function call in debug builds. 12:57 <@matches> So what is this "more code" going to do :P 12:57 < sulix> Slightly more modern opengl. 12:58 <@matches> Yeah, that would be a good idea 12:58 < sulix> In particular, uploading the content of a document to a VBO, and just re-rendering from that when needed. 12:58 <@matches> Cool 12:58 < sulix> Jumps from 9 fps -> 37 fps with 1024^2 objects. 12:59 < sulix> I've been without internet, though, so it's pretty broken in many ways, still. 12:59 < sulix> Like outline rects don't work. 12:59 < sulix> And it still uses a bunch of OpenGL 1.0 stuff. 12:59 < sulix> And for some reason the glPrimitiveRestartIndex() function isn't working. 13:00 < sulix> Also I need to write shaders at some point, which will be work. 13:00 <@matches> I just found the best comment in an IEEE email list 13:00 <@matches> We should totally use it 13:01 <@matches> "It is too late now to repair the mistakes of the past that are present in millions of installed systems, but it is good to know that careful research before designing hardware can be helpful" 13:01 < sulix> Oh man, that's basically the thesis in one sentance. 13:02 <@matches> Dibs! 13:02 <@matches> Although I doubt anyone will care if we both quote it 13:03 < sulix> One thing I did discover reading my OpenGL book is that I think we can get OpenGL to use doubles with some shader hackery. 13:03 <@matches> :O 13:03 < sulix> Then again, the book was (partly) written by (one of) the authors of fglrx, so take it with the requisite salt. 13:04 <@matches> Ah, so how many goats were required? 13:05 < sulix> Just the two, I think. 13:06 <@matches> This email message seems sort of vaguely relevant? It's the "infamous double rounding problem" 13:06 < sulix> I take it that you worked out how to swap between CPU and GPU transforms with right-click. 13:07 <@matches> I read it in the commit message 13:08 < sulix> I was quite happy with how much nicer things ran with CPU transforms and doubles. 13:08 <@matches> I think I can see a difference zooming in far enough 13:08 <@matches> Yeah that's a huge difference 13:08 <@matches> I had a tester that was going to automatically make images of the difference when you zoomed in really far 13:09 <@matches> But there were issues with the screen shot / bmp rendering 13:09 <@matches> Probably the bmp rendering 13:09 < sulix> .bmp files suck. 13:10 <@matches> They are nice and simple though? 13:10 <@matches> At least, the SDL API is nice and simple 13:10 < sulix> That's more a triumph of SDL than of the .bmp file format. 13:10 <@matches> After looking through gm6 files with a hex editor to try and extract sprites... 13:11 <@matches> Well we could always just fwrite the pixel buffer and fread it back 13:11 <@matches> If you want no one to be able to use our files without compiling our program :P 13:12 < sulix> I'm personally a fan of LodePNG, but I'm too lazy to hack it in at the moment: http://lodev.org/lodepng/ 13:13 < sulix> I'm probably going to get around to fixing all of the warnings in stb_truetype one day. 13:13 <@matches> Haha 13:13 <@matches> What about implementing an Oct-tree? 13:14 <@matches> So .bmp is just a header and then the raw pixel data? What's disgusting about that? No compression? 13:16 <@matches> Wait png is also just a header and then an IDAT section 13:17 <@matches> Oh well you can put lodepng in if you want I guess 13:17 <@matches> As long as I can open the images in eom 13:18 <@matches> Ah so PNG is compressed. I missed that 13:19 <@matches> Meh 13:19 <@matches> Oh and alpha channel 13:19 <@matches> Yeah 13:19 <@matches> I remember that now 13:20 <@matches> xpaint is the least shitty of the shitty sprite editors in debian, but it only stores RGB because it was designed around bmp and I guess they just hacked on exporting to other formats later 13:21 <@matches> If you open things with alpha it gets really confused 13:23 < sulix> You can put alpha in .bmp files, but then they sometimes crash KDE. 13:26 <@matches> We can just run all our bmp files through image magick 13:26 <@matches> convert a.bmp a.png 13:26 <@matches> Done 13:27 <@matches> Hmm, maybe if I opened the data from the gm6 files as png they would work, I was assuming they were bmps -_- 13:27 <@matches> Actually gif 13:27 <@matches> Probably 13:28 <@matches> Since it has "Save as gif" 13:28 <@matches> But that is not relevant to this project 13:33 < sulix> Damn, just discovered that the opengl feature I was using for rectangle outlines is not supported by my laptop's hardware. 13:34 < sulix> (This explains one of the bugs I've been seeing, but sadly only one) 13:47 < sulix> Okay, remaining code pushed. 13:47 < sulix> I am sorry. 13:53 <@matches> I'm messing around trying to do something evil so I'll merge later 13:53 <@matches> But you don't seem to call ToggleGPUTransform when there is a right click 13:54 <@matches> Oh wait, I need to make clean 13:54 <@matches> Cool 13:54 <@matches> (So much for our Makefile magically tracking the header files :S) 13:58 < sulix> It does it for every header file except ones included by main.cpp because of the weird main.cpp swapping stuff. 13:59 <@matches> That main swapping stuff is amazing 13:59 <@matches> It is worth it 13:59 <@matches> Except main.cpp ends up eventually including all the header files 14:00 <@matches> I think there is an alternative Makefile that just has every single header file in the current directory as a dependency for each .o file 14:01 <@matches> But I'm normally used to running make clean anyway 14:22 <@matches> Eh I was going to make a video of the difference between GPU and CPU coord transforms but it's not that great 14:23 <@matches> Whatever you have done does not look happy 14:24 < sulix> It takes like 5 minutes to DebugDumpObjects with a million objects, but it works okay* after that. 14:24 <@matches> Yeah ok 14:24 < sulix> *well, sort-of. 14:25 < sulix> If you just want to show off the precision, getting rid of most of those objects is probably the right thing to do. 14:25 <@matches> Interesting things happen when you zoom out really far 14:25 <@matches> Do we care about that 14:25 < sulix> I'm going to go with "no". 14:26 <@matches> Ah, but the rectangles are not all the same size 14:26 < sulix> This is a product of rounding to the nearest pixel. They'd be fine with antialiasing. 14:29 <@matches> I have pushed a single line contribution 14:29 <@matches> I decided not to bother with all the changes I made to make the video prettier 14:29 <@matches> Since I can't actually capture my desktop properly anyway 14:30 <@matches> I suppose I could make it render bmps and ffmpeg them all but that is way too much effort 14:31 <@matches> So 14:31 <@matches> Literature Reviews 14:31 <@matches> They are a thing 14:38 <@matches> I probably should not reference an email thread 14:53 <@matches> In other news, I think this jvm FPU doesn't actually implement sqrt 14:57 <@matches> It always gives 0x0 on sqrt ops 14:57 <@matches> I certainly hope there isn't a jvm somewhere that just doesn't do square roots 14:58 <@matches> They probably hacked it into some other part of their project instead of putting it in the FPU 16:08 <@matches> So fprintf style formatting isn't very clever when it comes to floats vs doubles vs long doubles 16:11 <@matches> Eg: %lf will work for either floats or doubles and %f will work for either floats or doubles (by truncating) but %llf is the only thing that works for long doubles and it only works for long doubles 16:12 <@matches> s/truncating/casting whatever 16:52 <@matches> We can compile with long double 16:52 <@matches> I suspect this may break things but whatever 16:52 <@matches> Running calculatepi on motsugo to see how much difference it actually makes... 17:08 <@matches> Charles Babbage seems like an interesting fellow 17:09 <@matches> "e sought to prove the 17:09 <@matches> reality of the devil by drawing with his blood a 17:09 <@matches> circle on the floor and repeating the Lord’s prayer 17:09 <@matches> backward" 17:09 <@matches> The things one does for science 17:44 <@matches> Reading about Charles Babbage counts as Literature Review... 17:44 <@matches> Actually I'm trying to find a paper written *by* him 17:44 <@matches> Since apparently he came up with Floating Point representations 22:11 <@matches> Found an actual paper talking about floating points on GPUs 22:12 <@matches> It says they don't conform to IEEE and also the manufacturers don't like to tell people what they do do 22:12 <@matches> So they wrote a version of Paranoia, which was a test program for computers in the 1980s before IEEE, to work out the characteristics of flops on various GPUs 22:13 <@matches> This is probably of interest 22:14 <@matches> So far one of the best papers I have on algorithms in software is actually one talking about implementing those algorithms in hardware instead 22:15 <@matches> I also have a random obituary to Charles Babbage just because 22:16 <@matches> Unfortunately UWA directs me to some useless website that just tells me the citation details and doesn't give me a download for any of Babbage's papers 22:17 <@matches> He has some books but they are mostly about economics 22:18 <@matches> Would have been nice if he'd written something that says "I have invented floating point" but I guess not 22:18 <@matches> That's only really of historical interest but it'd be nice --- Day changed Tue Apr 22 2014 01:17 <@matches> Urgh looking at the git diff 01:17 <@matches> I really have not accomplished much 01:30 <@matches> Oooh, motsugo finally got to a number of intervals where long double is better than double 11:56 < sulix> So it turns out that I've broken the open-source GL drivers. 11:56 < sulix> They don't support one of the features ("primitive restart") we need when in compatibility mode. 11:56 < sulix> So I guess now I've got to rewrite everything to use OpenGL 3. 14:47 <@matches> ? 14:48 <@matches> I should probably look more carefully at what the OpenGL stuff is doing nowdays 14:49 <@matches> Downgrading to OpenGL 3 sounds drastic 14:50 <@matches> Wait 3 is the OK one, 4 is the new one 14:50 <@matches> 1 is the ancient one 14:52 <@matches> I see pointer arithmetic... 14:53 <@matches> banana would be furious 14:53 <@matches> should be using std::super_ptr_unsegfaultable_arith 14:53 <@matches> (I am not a fan of the smart pointers) 14:55 <@matches> *indexData = 0xFFFFFFFF; // Primitive restart. 14:55 <@matches> I do not know what is going on here :S 14:58 <@matches> Ahh I get it now 14:58 <@matches> Reading commit messages turns out to be useful 15:04 <@matches> git blame for view.cpp reveals that I still own the opening braces on some things 15:05 <@matches> That's about it :P 15:06 <@matches> I'm going to keep looking at rounding errors and maybe have a better thing than calculating pi 15:06 <@matches> As a bench mark 15:07 <@matches> I might look at Paranoia 15:07 <@matches> Although it was originally in BASIC 15:07 <@matches> And ~7000 lines 15:07 <@matches> With almost no whitespace characters 15:07 <@matches> And totally no indents 15:08 <@matches> I sometimes get the feeling people used to be smarter than we are now... 15:08 <@matches> Then I remember that those people are ultimately responsible for the tools we use now 15:15 < sulix> Speaking of tools we use now, I think I've just got the debug font code to not only randomly corrupt a varible, but also cause valgrind to crash. 15:18 < sulix> Okay, we need to fix that makefile at some point. 15:38 <@matches> make clean? 15:41 <@matches> It's not actually swapping out main.cpp 15:41 <@matches> It just doesn't have main.o in the link objects and has main in the $(BIN) target and the testers in the tests/% target 15:42 <@matches> I guess that is swapping out main but MAIN is not being changed 15:42 <@matches> derp 15:45 <@matches> I think I fixed it? 15:45 < sulix> Ah. Well, you've got a merge conflict to look forward to. 15:45 <@matches> Not if I just NEVER COMMIT IT 15:46 <@matches> I'm going to call your fix being right and mine being a horrible hack 15:46 <@matches> Ok I pullsd some changes to graphics stuff, is that it or is there more? 15:46 < sulix> I haven't fixed it, I've just gone and bu(gg|ff)ered up the font stuff. 15:47 <@matches> So it's not meant to render unless something changes? But the debug font stuff is changing so it needs to keep rendering? 15:48 <@matches> I see a lot of "Flushing Debug Font arrays" 15:48 < sulix> The debug font stuff is separate from the whole view system. 15:48 <@matches> That makes sense 15:48 < sulix> It's just trying to fill up a buffer of quads with individual characters in it and then draws them when the buffer gets full. 15:49 < sulix> One more step on the path of getting rid of all of the OpenGL 1.1 stuff. 15:50 <@matches> Haha 15:50 <@matches> git stash seems to think I modified graphicsbuffer.h and screen.h 15:51 <@matches> git diff seems to think everything is identical 15:51 <@matches> I'm just going to git reset the things I didn't actually change... 15:52 < sulix> I do that far too often. 15:52 <@matches> Oh there is a comment "//test" for testing the Makefile 15:53 <@matches> And a comment "This isn't the Screen class?" where you copy/pasted the screen class description for the GraphicsBuffer class 15:53 <@matches> I don't think they need to be preserved 15:54 < sulix> Yeah, I should have got rid of that screen class bit by now. 15:55 <@matches> Have a 2 line commit 15:55 < sulix> The best kind. 15:55 <@matches> I really need to cut back on the new line creep 15:56 <@matches> It's like I can't add a line by itself without putting in extra whitespace 15:57 <@matches> Uh oh we've ran out of coffee here 15:58 <@matches> I'm slightly scared by how much the graphics code has increased since I last actually understood how it worked... 15:59 <@matches> Can you change those *vertexData to *(vertexData++) or is that considered even uglier 16:03 < sulix> I thought of that, but given how much pointer arithmetic debugging I was going to do, I wanted it to be really obvious when the pointer was being incremented. 16:03 < sulix> The plan is to have a nice AppendFloat() function or similar that will do this eventually. 16:05 < sulix> Hmm: "Buffer usage warning: Analysis of buffer object 2 (bound to GL_ARRAY_BUFFER_ARB) usage indicates that the GPU is the primary producer and consumer of data for this buffer object. The usage hint supplied with this buffer object, GL_STATIC_DRAW, is inconsistent with this usage pattern. Try using GL_STREAM_COPY_ARB, GL_STATIC_COPY_ARB or GL_DYNAMIC_COPY_ARB instead. 16:06 < sulix> Thanks nVidia. 16:06 < sulix> Now if only we were using OpenGL 4.4 which got rid of buffer usage hints entirely. 16:29 <@matches> Also I think you forgot the naming scheme :P 16:30 <@matches> vertex_data 16:31 <@matches> I will go back to pretending to be doing a literature review 16:32 <@matches> Instead I will probably plot some graphs 16:48 <@matches> So 16:48 <@matches> If you look up "Handbook of Floating Point Arithmetic" on google (which lots of things like to reference these days) 16:48 <@matches> You can download the entire thing 16:48 <@matches> I was prepared to pay like $20 for it on amazon 16:49 <@matches> Oh amazon doesn't sell actual books anymore though does it? 16:49 <@matches> No they do have it 16:50 <@matches> For $100... 16:50 <@matches> I think I'll just stick with my free pdf thanks 16:55 <@matches> "Handbook" being 579 pages... 17:04 <@matches> I think if a textbook is citing blog posts we can probably get away with it 17:05 <@matches> Oh my god I love this textbook 17:05 < sulix> I was watching a conference talk last night when the presenter just said: "this technique is described on this guys blog. Here's a link." 17:05 <@matches> "Table 1.1 gives the results obtained by compiling Program 1.1 and running on a Pentium4, using the GNU Compiler Collection and the Linux system" 17:06 <@matches> [Complete C code for Program 1.1 follows] 17:06 <@matches> None of this "Pseudo code" crap 17:07 < sulix> Clearly we should get an extra 10% for every line of pointer arithmetic in our theses. 17:07 <@matches> There' 17:07 <@matches> s a problem here 17:07 <@matches> How do I not make the entire literature review just paraphrased from this one text book 17:08 <@matches> Mr Gullible and the Chaotic Bank Society! 17:08 <@matches> It has stories! 17:08 <@matches> Parents should read this textbook to their children 17:09 < sulix> I'm pretty certain I know someone with a data structures and algorithms picture book... 17:09 <@matches> That reminds me of a children's book I wrote about multithreading 17:10 <@matches> I should probably scan it one day 17:10 < sulix> Did it begin "Once upa timeon... 17:10 <@matches> I think it did actually 17:10 <@matches> Once upon a time there was a process who had a lot of work to do... 17:11 <@matches> "I should probably scan it one day" - Why not TODAY! 17:11 * matches goes searching 17:16 <@matches> It is no where to be found 17:16 <@matches> I distinctly remember going to throw it out and deciding not to, but not where it actually went 17:27 <@matches> So maybe compiling a bunch of HFPA's examples using our Real type is a good way to make benchmarks 17:27 <@matches> I don't know 17:27 <@matches> My part of the project seems to move further and further away from the document formats thing 17:27 <@matches> Maybe I'll try and compile the GPU Paranoia 17:28 <@matches> Hah 17:34 <@matches> It seems like whatever Mathematica does is what we should do 17:35 <@matches> I wonder if wolfram is open about how Mathematica actually works 17:35 <@matches> I don't think they are 17:35 <@matches> The CQM lecturer for physics found a bug in Mathematica's number representation once that she showed us 17:35 <@matches> Apparently she reported it years ago and it's still there 17:36 <@matches> This segued nicely into why we should learn fortran --- Day changed Wed Apr 23 2014 14:00 <@matches> IEEE's float encoding is inconvenient 14:01 <@matches> The mantissa is like, reversed 14:01 <@matches> b_{23-i} * 2^{-i} 14:19 <@matches> And the implicit extra 1 except when it isn't is a pain in the ass as well 14:19 <@matches> It's like 14:19 <@matches> I can't just copy the right bits I have to think 14:19 <@matches> What is this 14:19 <@matches> Mental effort 14:19 <@matches> Blargh 14:20 <@matches> I should have just stuck with the 8 bit floats with their 2 sign bits 14:20 <@matches> The hydra float 15:17 <@matches> Wow you get really different representations with an IEEE encoding of the bits 15:17 <@matches> ... 15:17 <@matches> I think I liked just treating the two parts as integers in the order they were stored better 15:18 <@matches> I have to call pow(3) and a floating point division for every '1' in the mantissa to get it to agree with IEEE 15:19 <@matches> Unless I'm missing some obvious trick 15:20 <@matches> But in IEEE the mantissa is not an integer 15:37 <@matches> Ooookkk 15:38 <@matches> You're precision doesn't disappear as fast when you do it that way 15:38 <@matches> Your 15:38 <@matches> Whatever --- Day changed Thu Apr 24 2014 14:40 -!- You're now known as notmatches 14:40 -!- You're now known as matches 14:41 <@matches> Ok, less spammy channel time 14:41 -!- mode/#ipdf [+b m:matches!*@*] by matches 14:41 <@matches> Spam 14:41 <@matches> Dammit 14:42 -!- mode/#ipdf [-o matches] by matches 14:42 < matches> Spam 14:43 < matches> Yay 14:43 < matches> ... this will all appear in the next git commit won't it -_- 14:52 -!- You're now known as notmatches 14:52 -!- You're now known as matches --- Day changed Sat Apr 26 2014 00:45 -!- mode/#ipdf [+o matches] by OperServ 00:46 <@matches> Incoming "at least it is self consistent in its wrongness" floating point conversion 00:48 -!- mode/#ipdf [-o matches] by matches 00:48 < matches> Still can't talk 00:48 < matches> Excellent --- Day changed Sun Apr 27 2014 17:10 < sulix> I finally got ipdf working on my laptop again by porting everything to OpenGL 3.1. 17:10 < sulix> I'm so sorry about how ugly the code now is, by the way. 18:04 -!- mode/#ipdf [+o matches] by OperServ 18:04 -!- Pommers [bobgeorge33@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 18:05 < Pommers> You know what a really good feature for a PDF reader would be? The ability to have it completely borderless without menus, so you just see the page! 18:05 -!- Pommers [bobgeorge33@motsugo.ucc.gu.uwa.edu.au] has left #ipdf [] 18:06 <@matches> Wat 18:06 <@matches> Well we've got that 18:06 <@matches> We just can't read pdfs 18:07 <@matches> Did you get much done not going to the cleanup? 18:07 <@matches> I managed to transfer some dust from one location to another location, and then the wind blew it back in my face 18:08 <@matches> Then I looked at Frames' proposal and despaired at how much it is actually complete and has words in it 18:08 <@matches> I think he's onto something with his plan of actually writing things 18:14 -!- matches changed the topic of #ipdf to: ipdf the pdf doesn't stand for pdf 18:14 -!- matches changed the topic of #ipdf to: ipdf the pdf doesn't stand for pdf but the df stands for df 18:14 -!- matches changed the topic of #ipdf to: Sort of 18:15 <@matches> I need a script to auto mute me... 18:15 < sulix> I spent basically all of today on that one commit. 18:15 -!- mode/#ipdf [-o matches] by matches 18:15 -!- mode/#ipdf [+o matches] by OperServ 18:15 < sulix> Whether or not that was more useful than the cleanup remains to be seen. 18:16 <@matches> I should look at it I guess :P 18:16 < sulix> It compiles* 18:16 < sulix> *but has lots of warnings. 18:16 <@matches> It can't be worse than my tester that converts floats to floats 18:17 < sulix> I'm pretty certain it can be and is worse. 18:17 <@matches> However I've realised I kind of actually do need to be able to do that 18:17 <@matches> Woah 3k+ lines 18:17 <@matches> * 4k+ lines 18:18 < sulix> Most of it was autogenerated, but still... 18:18 * matches weeps for OpenGL 1 18:18 < sulix> You don't realise how much you miss it until it's gone... 18:19 <@matches> So what does all this stuff actually do 18:19 <@matches> Because I could see rectangles and things just fine without it 18:19 < sulix> Exactly the same thing as before but it works on my laptop now. 18:19 <@matches> I see a shader program, that's obviously good 18:20 <@matches> Actually I see code for a shader but no shader yet 18:20 < sulix> The shaders are all #defines, I'm afraid. 18:22 <@matches> What was wrong with your laptop? 18:23 < sulix> It doesn't support the OpenGL compatibility mode, so --- as I was using the OpenGL 3.1 feature of "primitive restart", I had to code the entire thing in OpenGL 3.1 18:23 < sulix> On the bright side, this paves the way for doing things like getting the GPU to use doubles. 18:26 <@matches> Ooh 18:27 < sulix> (also halves) 18:27 < sulix> (halfs?) 18:27 <@matches> Do GPUs use IEEE floats? I had a reference that seemed to be complaining they didn't 18:27 <@matches> Although it was circa 2007 18:28 < sulix> I don't think that there's a requirement that they internally use them, but they do read and write them. 18:28 < sulix> A bit like how x86 processors use(d) 80 bit reals internally and rounded when reading/writing to memory. 18:28 <@matches> Do halves have a different mantissa encoding 18:29 <@matches> The examples given on wikipedia seem wrong 18:30 < sulix> I think this is the canonical description: http://www.opengl.org/registry/specs/NV/half_float.txt 18:33 <@matches> That would be before IEEE specified half (binary16) but its the same summation for the mantissa anyway 18:33 <@matches> binary16 is (briefly) in the 2008 revised 754 18:34 <@matches> So I think wikipedia is giving a wrong example, but I'm not confident enough to go and change wikipedia 18:35 <@matches> Also I just realised my conversion of the mantissa to a Real is horrible 18:35 <@matches> Oh well, it can get fixed later 18:36 <@matches> Hopefully I can finish my fluid mechanics assignment quick enough to actually work on my progress report / proposal / thing 18:36 <@matches> (Hah) 18:36 -!- mode/#ipdf [-o matches] by matches 18:37 < sulix> Yeah, I'm going to see how much Lit review I can write for tomorrow. :/ --- Day changed Mon Apr 28 2014 22:06 -!- mode/#ipdf [+o matches] by OperServ 22:10 <@matches> Must find motivation to work on Lit Review at 10pm... --- Day changed Tue Apr 29 2014 10:06 <@matches> Must find motivation to work on Lit Review at 10am... --- Day changed Wed Apr 30 2014 13:04 <@matches> I wanted to rasterise a vector image so I could compare them at the same scale ("These look the same!") and zoomed ("This one looks crappier!) 13:04 <@matches> But because vector graphics editor/viewers don't use pixels as units but they do when they export to a bitmap, it's difficult to actually get them to look the same 13:04 <@matches> Before scaling 13:05 <@matches> I guess a screenshot tool might be the best way 13:06 <@matches> I don't know if I need to do this really 13:07 <@matches> I guess Mechanical and Chemical engineers marking this will probably benefit from having an example 13:07 <@matches> Doesn't everyone know the difference between vector and raster graphics 13:07 <@matches> Where was that paper that had tux vector and rasterised 13:10 <@matches> Ah, worth2003xr.pdf 13:11 <@matches> If it's in a paper I guess it can go in a Lit Review 13:11 <@matches> At least until I have something better 13:15 <@matches> Kind of ironic that the image I am using was actually scanned first as a bitmap and then converted to vector using Trace Bitmap 13:57 <@matches> Ah, it's actually impossible to get it to be exactly the same, because even taking a screenshot on my own screen it will then be different depending on the display of whoever reads the digital pdf 13:57 <@matches> Oh well 13:58 <@matches> I suppose "It looks shittier" will have to suffice without trying to make them look exactly the same before scaling 13:59 <@matches> I have spent WAY too long making this example 13:59 <@matches> I could have just gone "See \cite{worth2003xr.pdf}" 16:00 <@matches> So it might be worth talking about dpi in pdf viewers and how it SUCKS 20:17 -!- mode/#ipdf [-o matches] by matches 21:14 -!- mode/#ipdf [+o matches] by OperServ 21:46 <@matches> I have perpetrated XML on the codebase 21:47 <@matches> I have grand visions of our code supporting SVGs 21:47 <@matches> I also have grand visions of actually doing a Literature Review 21:50 * sulix git pull's with some trepidation. 21:52 < sulix> Never heard of pugixml before but it looks okay. 21:55 <@matches> The W3C XML specification is pretty terrifying 21:56 <@matches> I will feel more like I've satisfied the "Document Formats" part of the Literature Review if I say some things about it 21:57 <@matches> Well SVG in particular 21:57 <@matches> SVG defines a "minimum" precision of IEEE binary32 21:58 <@matches> But there's a specification for "High Quality" viewers that have to use binary64 21:58 <@matches> That's probably the only real thing relevant directly to our problem --- Day changed Thu May 01 2014 01:23 <@matches> It's May 1st 01:23 <@matches> This means we can no longer say "The Literature Review is due Next Month" 01:23 <@matches> IT'S DUE THIS MONTH 01:23 * matches freaks out 01:23 <@matches> ... but after sleep 01:25 <@matches> Page 12 of my Literature Review by the way 01:25 <@matches> Is the only page I like 16:34 <@matches> The C version of paranoia compiled for me 16:34 <@matches> Not terribly exciting (I have an IEEE 754 compatible processor! Amazing) 22:17 <@matches> W Kahan's website is a very interesting if slightly difficult read 22:24 <@matches> He appears to have written this 80 page pdf in a day 22:27 <@matches> It kind of reads like one of those religious propaganda pamphlets 22:27 <@matches> "Java is the Work of Satan" 22:27 <@matches> "Kernighan-Ritcie C floating-point semantics are the light" 22:28 <@matches> But every so often he has a graph or example that makes him seem less crazy 22:34 <@matches> "And now Java forbits you to mention or use extra-precise long double arithmetic, though IEEE Standard 754 recommends its use and over 95% of computers on desktops have it built into their hardware. You paid for it, but Java denies you its benefits." 22:34 <@matches> Java has long double now right? 22:34 <@matches> Although that JOP I was looking at was just 32 bit 22:36 <@matches> Ah, java.lang.math.BigDecimal 22:37 <@matches> "But be careful with division, because it will throw exceptions if it's like 1/3, then it will be Non-terminating decimal expansion." 22:37 <@matches> That sounds horrifying 22:40 -!- mode/#ipdf [-o matches] by matches --- Day changed Sat May 03 2014 22:01 < sulix> My crazy idea to you would be to research p-adic number representations. 22:01 < sulix> It's been a while, but they were mentioned a couple of times in pure maths units and seemed interesting/crazy and I can't remember much about them. 22:28 -!- mode/#ipdf [+o matches] by OperServ 22:29 <@matches> I will look at them, the "just use a float but with more bits until you run out of memory" doesn't seem a very well thought out approach 22:29 <@matches> Maybe someone actually cares enough to research better ways 22:29 <@matches> I mean, something's wrong with an idea when you can write "1/3" and have a runtime exception (re: Java BigNumber) 22:30 <@matches> I plan to write some nasty things about Java based on Kahan's rants so as to gloss over the fact that it has BigNumber built into it and forstall the inevitable "Why didn't you use Java!" 22:31 < sulix> I think we want to truncate to whatever the most accurate you can see at the given zoom level. 22:31 <@matches> Yeah 22:32 <@matches> It annoys me that XML and HTML specs don't have a PDF version 22:32 < sulix> I've been printing to pdf for some of those things. 22:33 <@matches> None of the links to different sections would work though 22:35 <@matches> Specifications are thrilling 22:35 <@matches> "How to read this specification" 22:35 <@matches> "This specification should be read like all other specifications" 22:35 <@matches> Oh wait 22:35 <@matches> It actually gets better 22:35 <@matches> Is that... 22:35 <@matches> Humour! 22:36 <@matches> I thought that wasn't allowed! 22:36 <@matches> "First it should be read cover-to-cover, multiple times. Then, it should be read backwards at least once. Then it should be read by picking random sections from the contents list and following all the cross references" 22:37 <@matches> As much as I love the idea of reading 626 pages of specification backwards... --- Day changed Tue May 06 2014 00:39 <@matches> http://szmoore.net/ipdf/sam/rate-my-litreview.py 00:39 <@matches> Tim will be thrilled! 00:40 <@matches> I'm probably going to really regret making that 00:41 <@matches> The regret is rising to the surface 00:41 <@matches> It's an example of an interactive document format 00:41 <@matches> The pixels or perish guy would approve 00:43 <@matches> So much regret 00:43 -!- mode/#ipdf [-o matches] by matches 23:37 -!- mode/#ipdf [+o matches] by OperServ 23:38 <@matches> So, I have this book called "Computer Graphics" that is pretty amazing 23:38 <@matches> Funnily enough it has all the algorithms in it 23:38 <@matches> For computer graphics 23:38 <@matches> Probably should have been reading it ages ago but I thought we were worrying more about precision 23:38 <@matches> I don't even know anymore 23:39 <@matches> Have to read 500pg textbook on graphics, 500pg textbook on floating point numbers, 500pg PDF/PostScript standards... 23:39 <@matches> Too many pages 23:39 <@matches> Anyway it has a section on Octrees 23:39 <@matches> But don't worry 23:39 <@matches> It mentions Quad trees 23:39 <@matches> It also actually mentions fractals 23:39 <@matches> As a thing 23:40 <@matches> In other news, extending the document we have at the moment to allow anything other than rectangles will be interesting 23:41 <@matches> Did you do this on purpose? :P --- Day changed Wed May 07 2014 12:32 <@matches> We need to do something about all the warnings generated by the magic OpenGL 3 stuff 12:32 <@matches> It's making it hard to sport warnings that I actually care about 12:33 <@matches> Like: You forgot to return a value in this function :S 13:52 <@matches> Gah I did it again 13:52 <@matches> auto is dangerous 13:53 <@matches> Possibly because it's buggy 13:53 <@matches> I can't actually see any compiler warnings at all 17:39 <@matches> So you can almost maybe see a difference between beziers calculated using floats and doubles 17:40 <@matches> If you squint 17:40 <@matches> And view them on different monitors 17:41 <@matches> Ah there we go 17:41 <@matches> I successfully broke it 17:42 <@matches> When you round to pixel positions it doesn't make a difference 17:43 <@matches> But on the other hand if you calculate beziers using really big numbers they look wierd :P 17:43 <@matches> That's important 17:43 <@matches> Because if you have an arbitrary infinite document you might be at coordinate positions that are really big 17:43 <@matches> Captain Obvious strikes again 17:45 <@matches> I think I will make a video of a circle moving towards infinity 17:45 <@matches> This probably won't help the literature view much but it's too tempting to resist 17:46 <@matches> I gave up trying to deal with our document format so I currently just generate vector > and then map that to a bitmap :P --- Day changed Thu May 08 2014 10:57 <@matches> So circle was a terrible example 10:57 <@matches> It stays as a circle 10:58 <@matches> Hopefully the first curve I tried wasn't just a bug 12:31 <@matches> I think it was a bug 13:35 <@matches> There are bezier things in ipdf/code/src/tests now 13:57 < sulix> I am very confused. 13:57 < sulix> It generates bitmaps of circles in varying shades of red? 13:58 * sulix decides to actually read the code. 14:03 < sulix> Ah: I see what it's doing now. 14:16 <@matches> Your first comment was pretty accurate :S 14:17 <@matches> I was trying to obtain some amazing animation of a circle that hopelessly collapsed or exploded or something 14:19 < sulix> I'm slightly terrified that it's generating a vector of points. 14:19 < sulix> On the other hand, it looks like the rest of the world is realising what a mistake making OpenGL 3 terrifying was. 14:19 <@matches> Yeah that's a bit lazy 14:19 <@matches> Although, is returning a vector optimisable? 14:20 < sulix> In C++11 it is. 14:20 < sulix> (But not C++98) 14:20 <@matches> C++11 is growing on me 14:20 < sulix> Yeah: I've found the same thing. 14:21 < sulix> I'm a bit scared about what that means, though. 14:21 < sulix> Maybe one day I'll think boost was a good thing, and then I'll truly be lost. 14:21 <@matches> Hahaha 14:21 <@matches> The lambdas remind me of Javascript :S 14:22 < sulix> I think lambdas are one of those things that are good for you in moderation, but poisonous in large quantities. 14:22 <@matches> Probably 14:23 < sulix> I won't be around on Monday, btw, so I'll miss the meeting. 14:23 < sulix> (Also I'm missing out on Codejam, sadly) 14:23 <@matches> No! 14:23 <@matches> (To both of those things) 14:24 <@matches> Oh god that means I need to make double the progress 14:25 < sulix> I spoke to Tim, he said that it might be worth cancelling the meeting altogether. 14:26 <@matches> Haha 14:26 <@matches> I'm not sure if I should take that as a good or bad sign 14:27 <@matches> I'm not going great with the literature review 14:28 < sulix> I rated a bit of it. 14:28 < sulix> (Though there wasn't a submit button, and it took me a few goes to get through the Turing test) 14:28 <@matches> Page 20? 14:28 <@matches> Haha 14:28 <@matches> The turing test defaults to the accepted answer though! 14:28 <@matches> You have to actually change it to get it wrong 14:29 < sulix> Yeah, I thought it was a trick question. 14:29 <@matches> Maybe I'll give Tim a slightly less joke-worthy version of Rate My LitReview when the draft is done 14:29 <@matches> ... when hell has frozen over... 14:29 <@matches> Whichever comes first 14:31 < sulix> You should read James Mickens' USENIX articles: mkdir -p vogl/vogl_build/bin/release64 && cd $_ 14:31 < sulix> cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_X64=On ../../.. 14:31 < sulix> make -j 10 14:31 < sulix> (Also I should paste the right thing in) 14:31 < sulix> http://research.microsoft.com/en-us/people/mickens/ 14:32 <@matches> Ah yes, I will read those at some point 14:32 * matches downloads the first one, telling himself he will not read it until working on the lit review 14:33 * matches reads it anyway 14:33 * sulix feels guilty about not doing lit review at the moment, too. 14:40 <@matches> Have you heard of /read Computer Graphics by Hearn and Baker? 14:40 <@matches> I have the ancient "In the dawn before OpenGL 1.0" version 14:41 <@matches> There is a section mentioning "GL" 14:41 <@matches> I don't think they use GPU anywhere, they call them "Display Rasterisers" or something 14:42 <@matches> Display Processor 14:43 <@matches> A Display Processing Unit is a Display Processor for a Random Scan (vector) display system 14:43 <@matches> Input devices are interesting too 14:44 <@matches> "Input Dials" 14:44 <@matches> A box of variable resistors basically 14:45 <@matches> Working with computers in the 70s/80s would have been interesting although probably just as horrible as it is today 14:45 <@matches> But at least it would have been less "webby" 14:46 <@matches> Where "How do I centre a div" is a deep philosophical question 14:48 <@matches> I should probably obtain / read a newer edition of this if I want to put it in my lit review? 14:48 <@matches> Although it is referrring to the same papers we had about Bressenheim 15:14 <@matches> Oh my god they mention precision! --- Log closed Thu May 08 17:04:49 2014 --- Log opened Thu May 08 18:56:39 2014 18:56 -!- matches [matches@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 18:56 -!- Irssi: #ipdf: Total of 2 nicks [0 ops, 0 halfops, 0 voices, 2 normal] 18:56 -!- Irssi: Join to #ipdf was synced in 3 secs 19:55 < matches> Bresenham made a tutorial on rasterisation 19:56 -!- mode/#ipdf [+o matches] by OperServ 19:56 <@matches> Bresenham has a nice tutorial about rasterising 19:56 <@matches> Ties in with the "Since mankind came down from the trees" angle 19:57 <@matches> "Needlepoint or counted cross-stitch, such as that popularised by the image on a box of Whitman Sampler chocolates..." 19:57 <@matches> I'm not sure how to relate the rasterisation stuff to the precision stuff 19:58 <@matches> You have to make a pretty big rounding error to end up in the wrong pixel 19:59 <@matches> Hearn and Baker mention rounding errors as being one reason why you don't want to use floats and then round them when rasterising things 19:59 <@matches> The (bigger) reason being that floating point operations are expensive 20:00 <@matches> They say pixels could move from the line in the DDA algorithm for long lines... I wonder how long they mean... 1e38 pixels? :P 20:02 <@matches> I want to actually make a drawing of things that look different due to rounding errors dammit! 20:03 <@matches> None of this "here is a sentence or two of handwaving" 20:04 <@matches> Maybe rounding errors were a problem on computers with 8 bit floats and terrible resolution displays :P 20:04 <@matches> Except the worse your resolution the less you'd notice rounding errors 20:04 <@matches> Well the more you'd notice them, the less they'd happen? 20:04 <@matches> I don't know 20:05 -!- mode/#ipdf [-o matches] by matches 20:30 < sulix> These were recommended: http://www.amazon.com/Forman-S.-Acton/e/B001IYTXGY/?_encoding=UTF8&tag=mollrock-20&linkCode=ur2&qid=1358713701&camp=1789&sr=8-3&creative=390957 20:30 < sulix> (By a blog post, which turned out not to be about floating point precision, but does mention it: http://mollyrocket.com/casey/stream_0009.html ) 21:21 < matches> I'll look at them at some point 21:22 -!- mode/#ipdf [+o matches] by OperServ 21:22 <@matches> I'll look at them at some point 21:22 <@matches> I sort of got bogged down explaining how lines are drawn :S 21:22 <@matches> Graphics is complicated dammit 21:22 <@matches> I'll probably get more done if I just write about everything no matter how irrelevant 21:23 <@matches> Sooner or later I'll actually write something important and the rest can be appendicised 21:23 <@matches> Hopefully 21:25 <@matches> Oh dear, I have located some primitive form of blog 21:26 <@matches> Well, it talks about things, so I'll reference it... 21:26 <@matches> "The good-looking textured light-sourced bouncy fun smart and stretchy page" 21:26 <@matches> It's generally best to not go up a directory from the page you are looking at --- Day changed Sun May 18 2014 15:47 <@matches> So things are due soonish 15:47 <@matches> :S 20:09 <@matches> Are you alive, because I don't think I'm alive 20:10 -!- Irssi: #ipdf: Total of 2 nicks [1 ops, 0 halfops, 0 voices, 1 normal] 20:11 <@matches> I'm feeling pretty guilty about all that work I didn't do last week... 20:47 * sulix agrees entirely. 22:11 <@matches> I give up 22:11 <@matches> I will just have to face disappointment O'clock tomorrow 22:22 < sulix> I still have to put more work in before I feel I even deserve disappointment, I think... :/ 22:23 < sulix> I made the mistake of deleting the irrelevant bits from my lit review, and now there's almost nothing left! --- Day changed Mon May 19 2014 08:03 < sulix> At the risk of causing terror: is your final Lit review due on Friday too? 08:05 * sulix has discovered that his is, and is currently trying to work out how to type in the foetal position. 09:59 <@matches> Yeah it's due on Friday 09:59 <@matches> Today is not off to a good start 10:00 <@matches> I missed an 8am lab but I can't blame the 2 buses I missed because I actually forgot about it 10:00 <@matches> Then I missed the 2 buses 10:00 < sulix> Ouch. 10:00 <@matches> I think missing my tutorial this afternoon is a bad idea but on the other hand... lit review 10:02 < sulix> I'm frantically writing irrelevant stuff now. 10:03 < sulix> I'm a little concerned about my entire section on "Document Formats" basically only referencing some specs and "Pixels or Perish". 10:03 <@matches> That's what I do 10:03 < sulix> Whereas I have like 20 references for graphics papers that are almost totally irrelevant. 10:04 <@matches> I have a reference for shading on a vector display 10:04 <@matches> That's pretty irrelevant 10:04 < sulix> I've started referencing data structures that are "kinda similar I guess" to the Quadtree, as well. :/ 10:05 <@matches> I ham fisted it in with the paper about embedding 3d figures in documents 10:05 <@matches> Like "in the 70s even though people had algorithms for things they still drew the diagrams by hand!" 10:05 < sulix> Peasants! 10:06 <@matches> My section on number representations is pretty shite 10:06 <@matches> I still haven't finished floats 10:06 < sulix> Mine is currently under construction, as it were. 10:06 <@matches> And the whole point is supposed to be that floats are not good enough 10:07 < sulix> I've got a terrible thing about floats, but have started talking about arb. precision floats now. 10:07 <@matches> All I know about the alternatives are that they are basically still floats 10:07 <@matches> But with more bits... 10:07 < sulix> I also have some maths I made up that is maybe wrong. 10:07 <@matches> Will you be here in time for doom O'clock? 10:08 <@matches> *cough* I meant eleven 10:08 < sulix> We can but hope. 10:08 < sulix> I'm sort-of counting on the meeting not happening until 11:20 or so. :/ 10:09 <@matches> I'll show him Rate My Lit Review 10:09 <@matches> That'll distract attention from the lack of Lit Review 10:09 <@matches> I'm also assuming no one is ever going to read these IRC logs 10:09 < sulix> We can but hope. 10:10 < sulix> I'm feeling dirty because I've just referenced the java standard library. 10:10 < sulix> Out damnéd 10:10 < sulix> java.math.BigDecimal. 10:15 <@matches> I was going to reference that at some point 10:16 <@matches> I feel like you've made more progress than I have been 10:17 <@matches> Possibly the decision to sleep last night was a poor one 10:26 < sulix> Having done the opposite: it wasn't. 10:30 <@matches> Argh I just got the icedove reminder for the meeting 10:32 <@matches> So I washed out my Guild (TM) Keep Cup (TM) this morning and now my tea tastes like detergent 16:37 <@matches> We didn't get the random asking about photoshop in here 16:37 <@matches> I feel left out 22:49 <@matches> sjy in #ucc mentioned Knuth's Metafontbook in regards to rendering fonts at infinite precision 22:49 <@matches> Yet another thing to get around to reading :S 22:49 <@matches> Before Friday :S 22:50 <@matches> Wednesday I guess if we meet Tim's deadline for a draft :P 23:08 <@matches> I guess I was meaning to reference the TeX book at *some* point 23:08 <@matches> So many things 23:08 <@matches> Oh dear it's 11pm already 23:08 <@matches> :-( 23:09 <@matches> Ok, so 23:09 <@matches> Metafont seems to basically be symbolic ways to define fonts 23:10 <@matches> Also Beziers 23:10 <@matches> All the beziers 23:10 <@matches> Good 23:11 <@matches> I was on the right track when I said Beziers were really important 23:11 <@matches> Knuth is so detailed 23:12 <@matches> Now I feel guilty about my cartesian line 23:12 <@matches> That I didn't reference Rene Descartes La Geometrie 1637 23:12 <@matches> I'm a monster 23:15 <@matches> I think instead of thinking of things as either interpreted or dom-y like Hayes does, the best way is to think about "What is in the document (eg: DOM)" and "How it is drawn" and you can either have your format care about both things or just one but obviously the most useful formats allow for both 23:16 <@matches> Actually scratch that 23:16 <@matches> I don't know anymore 23:16 <@matches> It's too philosophical 23:16 * matches goes back to floating point nubers 23:18 <@matches> So I wonder how much of PostScript is a shameless rip off of METAFONT 23:18 <@matches> It's not like you have to give credit when you are trying to sell something --- Day changed Tue May 20 2014 09:29 <@matches> So it's quite easy to do a 09:29 <@matches> "fractal" in SVG/Javascript 09:29 <@matches> Where easy does not necessarily mean it isn't horrifying 09:30 <@matches> Aaand there goes all my RAM 21:43 <@matches> Casually slipping in a footnote directing the reader to rabbitgame.net in my lit review... 21:43 <@matches> So my webby documents section is probably my least shitly written, or maybe that's just because it has pointless pretty pictures in it 21:44 <@matches> It is basically 21:44 <@matches> "Here are the w3c standards" 21:44 <@matches> "Here are some pretty pictures made with SVGs, can't you just see the DOM leaching out of them?" 21:44 <@matches> :S 21:45 <@matches> I'm not sure how well I am treading the line between actually reviewing literature and just giving examples of things --- Day changed Wed May 21 2014 12:09 <@matches> PDF is a mess of a "standard" 12:09 <@matches> As are all useful things I suppose 12:09 <@matches> As far as I can work out 12:09 <@matches> It is not a DOM but a graph 12:10 <@matches> However, it is also PostScript-y 12:10 <@matches> But they deal with "interactivity" 12:10 <@matches> By including XHTML 12:10 <@matches> And having an "action dictionary" which is literally just a string of javascript 12:11 <@matches> I just 12:11 <@matches> Can't even begin to understand how it all works 12:12 <@matches> But yeah, not really "Crippled Postscript" so much as "Everything including the kitchen sink except for a few bits of Postscript" 12:13 <@matches> So the Postscript part of it is no longer turing complete, but I don't think you can pretend something in which you can stick arbitrary Javascript isn't turing complete :S 12:13 <@matches> Oh and even though they have XHTML-ish stuff their Javascript API is totally different to W3Cs 12:13 <@matches> Hooray 12:14 <@matches> I suppose the fact that nothing except Adobe products seem to actually use Javascript/XHTML stuff is telling us something about this approach 12:15 <@matches> I reckon the ideal standard 12:15 <@matches> Would probably be the DOM but with the "we actually care about efficiency" parts of PDF 12:18 <@matches> The interactivity of web pages combined with the actually professional looking type setting of PDF 12:18 <@matches> Or just plain text files 12:19 <@matches> Plain text files are an underapreciated Document Format 12:23 <@matches> Ah, I think it sort of makes sense now 12:23 <@matches> PDF uses what is essentially PostScript to construct this graph thing 12:24 <@matches> And the graph thing can have elements in it that are just "Make this part of the graph the equivelant DOM from this XHTML" 12:25 <@matches> And it can also have elements that are "Execute this Javascript to dynamically change this graph" 12:25 <@matches> But the normal elements are just like PostScript as it would be sent to a printer to show the thing statically 12:26 <@matches> So when it's rendered it is interpreting the Postscripty bits and when its being interacted with it is updating the Postscripty bits 12:26 <@matches> I *think* 12:26 <@matches> This is different from the webby standards which don't really specify how things are actually drawn 12:27 <@matches> No wait it's not 12:27 <@matches> Argh I don't know 12:27 <@matches> You can't classify this shit 12:27 <@matches> Document Goes In -> Pixels Come Out 12:28 * matches despairs 12:49 < sulix> You will find (slightly) less despair if you relegate javascript to the footnote where it belongs. :P 13:07 < sulix> Hmm... the HTML 2 spec looks like it almost got properly IETF standardised. Might just reference that. 13:12 < sulix> Oh, they obsoleted it and replaced it with a "Just look at w3c" standard... 13:17 <@matches> But PDF isn't just flattened PostScript 13:17 <@matches> It is like, everything 13:17 <@matches> All merged into one horrifying standard 13:18 <@matches> Oh well 13:18 <@matches> I made my shape example in PostScript by removing the alpha 13:18 <@matches> I'm not sure whether there's any point in including it as a figure 13:18 <@matches> Most of the PostScript file is taken up by the header 13:19 < sulix> Holy balls, I just looked up the CSS spec. There are like 200 of them. 13:19 <@matches> Yeah I just used CSS2 13:19 <@matches> The others are like 13:19 <@matches> Colours 13:19 <@matches> Or something 13:20 < sulix> That's what I'm using, too. 13:20 < sulix> The tired and tested "what gets top result on google" method of paper selection. 13:20 <@matches> Closer examination reveals that most of the PostScript header is defining commands to be shorter :P 13:20 <@matches> Amazing 13:20 <@matches> Cairo probably needs to get referenced somewhere 13:21 <@matches> If only so I have a way out of my Javascript in PDF section by saying that Cairo doesn't support it 13:21 <@matches> I desperately need to escape the Javascript 13:25 < sulix> I think the secret is to use the phrase "rendering model" wherever possible. 13:51 <@matches> Dammit 13:51 <@matches> So I have that wierd shape in both SVG and PostScript now 13:51 <@matches> The SVG version fits beautifully and is wonderfully concise and you can see how SVG works 13:51 <@matches> The PostScript version is just like, BLARGH WALL OF TEXT 13:51 <@matches> ALSO WE DON'T HAVE ALPHA 13:52 <@matches> So I'm not sure whether to cut just the PostScript one or both of them now :S 13:53 <@matches> PDF looks distinctly not like it is just PostScript the more I think about it 13:53 <@matches> It's like "We are using the same model as PostScript in that commands go in and pixels come out" 13:54 <@matches> By that logic SVG is also the same 13:54 <@matches> I think what I should do is just make an appendix 13:54 <@matches> "A Shape in 20 Document Formats" 13:56 <@matches> SVG really is the most concise compared to PS and PDF 14:53 <@matches> Right I can simplify the god awful mess of PS a bit 14:54 <@matches> I'm hoping I can just say "Here is the PS reference and here is some PostScript as you can see it is interpreted-ish" 14:54 <@matches> Cairo appeared to draw each element backwards and reverse it after drawing it 14:54 <@matches> It is stupid 14:57 <@matches> Like, why bother doing definitions like m == moveto etc 14:57 <@matches> If you're just going to stick pointless crap in 14:57 <@matches> My document is half the size without using single letter definitions 15:31 < sulix> Welp. The wrath of Tim is upon us... 15:41 <@matches> I'm choosing to latch onto the "quite good" rather than "some way to go" 15:45 <@matches> It sort of sounds like "Well at least you gave me a pdf file" :P 15:48 < sulix> One day, all anyone will use are ipdf files... 15:50 <@matches> Right, TeX is very different from PostScript I think 15:50 <@matches> At least, pure tex 15:50 < sulix> Also, holy mackerel, I might have just found a paper on precision in document formats... 15:50 <@matches> :O 15:50 < sulix> It even quotes Kahan 15:50 <@matches> :OOO 15:50 < sulix> https://www.tug.org/TUGboat/tb28-3/tb90beebe.pdf 15:50 <@matches> What is it 15:50 <@matches> Emergency rewrite of entire lit review 15:51 < sulix> It's a bit TeX specific, but still. 15:51 <@matches> That's alright 15:51 <@matches> It ties in amazingly with my decision to hamfist TeX and Metafont into the lit review 15:52 <@matches> Although I'm not sure it is wise because it means I have to talk about fonts and things 15:53 <@matches> I wonder if "Fonts are just bezier curves" is sufficient 15:53 <@matches> They are always treated seperately to curved paths 15:53 <@matches> Which is understandable because it's a bit inconvenient if you want text in a document to have to define the paths for each glyph 15:54 <@matches> Anyway I'm glad my assertion that Beziers are the only curves we care about is proving true 16:33 <@matches> Are you in a position to retrieve this "envelope" 16:57 < sulix> Not tonight: I'm going to pick it up tomorrow morning. 16:58 < sulix> And hopefully replace it with a sparkling, glorious review of literature. 17:00 <@matches> :( 17:00 <@matches> I cannot concentrate now 17:00 <@matches> Because I haven't read the comments, I could be doing everything wrong! 17:02 <@matches> Admitedly I'm technically "working" right now 17:27 < sulix> My "Document Format Taxonomy" is almost complete... Just need to add SVG. 17:28 < sulix> (And close my eyes and assert that Microsoft Word documents are not actually documents or something) 17:28 <@matches> I am jealous 17:29 <@matches> I just added PostScript it's not particularly well written 17:29 < sulix> (I don't have any pretty pictures or code, though) 17:29 < sulix> I've discovered that, despite having totally different numbers for "implementation limits", the PostScript and PDF specs are (a) talking about the same data types and (b) lying. 17:32 <@matches> Bahaha 17:32 < sulix> Do you know where the SVG spec mentions precision? 17:33 <@matches> Ah, I regret not noting the page number 17:33 <@matches> But a text search should find it 17:33 <@matches> It specifically says things 17:33 <@matches> I am interested in whether or not Javascript is subject to the same requirements 17:34 < sulix> All I've found is "must be correct within 1px at 1:1 zoom", and "It is suggested that viewers attempt to keep a high degree of accuracy when zooming". 17:35 <@matches> There's something that is about IEEE floats 17:35 < sulix> Aaah... and a "High-Quality Viewer" must support at least double precision on coordinate system transforms. 17:35 < sulix> But "IEEE" does not show up in a search of the spec. 17:36 <@matches> Ah right 17:36 <@matches> My brain just inserts IEEE whenever I hear "single" or "double" now 17:36 <@matches> "An IEEE Double Episode of MasterChef!" 17:36 <@matches> (Which would probably be infinitely more exciting) 17:37 < sulix> (Or would it be NaNly more exciting...? :P) 17:38 <@matches> Speaking of "where things are" are we meant to reference page numbers in standards? 17:38 <@matches> I guess I'll find out when I read Tim's comments 17:39 <@matches> Excellent my lab finished 20 minutes early 17:39 <@matches> And also 40 minutes later than the other demonstrators :S 17:40 <@matches> Do you want me to pick up your comments and scan them and email them to you? :P 17:40 < sulix> That'd be great. 17:40 < sulix> Also probably depressing. 17:41 < sulix> But great. 17:41 <@matches> Alright, ETA Transperth + Scanner is probably broken O'clock 17:42 < sulix> I'll savour the blissful ignorance. 19:50 <@matches> I don't think scanning is worth it, I'll just spam the feedback into this channel 19:50 <@matches> First up, David's Lit Review 19:50 <@matches> There is either "Gool" or "Cool" or possibly "Good" written and underlined on the first page 19:51 <@matches> The opening paragraph is "A little overdramatic?" 19:51 <@matches> (Since it's a question, I'd like to voice a "No" opinion here) 19:51 <@matches> The DOM in a footnote is not defined 19:52 <@matches> Page 2 19:52 <@matches> There is a tick 19:52 <@matches> A question mark in regards to the hyphenated bit in the rendering paragraph 19:53 <@matches> Say "avoid" instead of lack 19:53 <@matches> Add what the "basic primitives" actually are 19:53 <@matches> There appears to be an issue with hyphenated phrases the hyphens are circled 19:53 <@matches> Another tick! 19:54 <@matches> Oh, you have a $2^64 - 1$\footnote{} which is unfortunate because it looks like $2^64 - 1^2$ 19:54 <@matches> That footnote (probably others?) would work in the paragraph without being footnote 19:54 <@matches> Fullstops go after \cite{} 19:55 <@matches> A tick (in regards to the quadtree diagram) 19:55 <@matches> The concluding comment 19:56 <@matches> "OK, Much to do (underline) There doesn't seem to be much scholarly references used. You have enough, but you seem to cite them in the context of their contributions to standards as opposed to how they addressed a research question or open problem" 19:57 <@matches> And (not even our references lists are safe!) 19:57 < sulix> Oh dear. 19:57 <@matches> Where referencing web pages, include the date retrieved 19:57 <@matches> That's it 19:57 <@matches> I shall move on to my own for completeness although you might not need to care 19:58 < sulix> Phew, that's not quite as horrible as it could have been, I guess. 19:58 <@matches> I also have "Good" 19:58 <@matches> There are some "I didn't read this bit but it had words that seemed vaguely relevant" ticks in Chapter 1 (Introduction) and 2 (Proposal) 19:59 <@matches> Sorry Tim if you read this 19:59 <@matches> But when I mark lab reports for Physics that's usually where I put the ticks :P 19:59 < sulix> (The secret comes out) 20:00 <@matches> (In my defence I did spend two hours marking the reports this morning and I am paid for none of them, so...) 20:01 <@matches> (It's the bits that I scribble all over that are where the marking gets done) 20:01 <@matches> (I think I've covered myself in case the lawyers of any of my students read this channel now, so I will resume my story...) 20:02 <@matches> Attention is called to the many glaring instances of [?] and "Refer to Section ?" 20:02 <@matches> :S 20:02 <@matches> I should probably define a vector image before comparing it to a raster image 20:02 <@matches> Incidentally my Fox looks amazing 20:02 <@matches> On printed paper 20:03 <@matches> (Tim didn't say that, that's just my modest opinion) 20:03 <@matches> Ahem. 20:03 < sulix> Can you see the difference between the vector and bitmap versions easily? 20:04 <@matches> At the original scale there is, alas, a very slight fuzziness 20:04 <@matches> But I reckon the markers will be old and blind 20:04 <@matches> Hmm, I should either be more careful about what I say here or stop logging this channel... 20:04 * sulix hopes they don't read that. 20:04 <@matches> Sorry markers 20:04 <@matches> I worship your power 20:04 <@matches> Please do not smite me 20:05 <@matches> The scaled up version is interesting 20:06 <@matches> It looks a bit like your circle with the blocky non-anti-aliased bit but actually anti-aliased by the pdf viewer 20:06 < sulix> I guess the scaling would be done by the printer's postscript RIP. 20:06 <@matches> Yeah I guess 20:07 < sulix> (Side note: I find the whole idea of Postscript interpreters being called RIPs somewhat fitting) 20:07 <@matches> The PDF decides not to antialias it and converts it to Postscript and then the postscript interpreter adds its own antialiasing? 20:07 <@matches> I don't know 20:07 * sulix joins the "SVG is the least broken format" club. 20:07 <@matches> It's very tempting to descend into footnote madness with this lit review 20:07 <@matches> "By the way, this very document is an example of this thing!" 20:07 <@matches> Etc 20:08 <@matches> Moving on 20:08 <@matches> The point of talking about vector displays at all is questioned (at least I think that's what the "Why?" refers to here) 20:08 <@matches> Or it could be "Why is there yet another ?? in this paragraph" I guess 20:09 <@matches> But probably the former 20:09 <@matches> I do not have space to include Bresenham's algorithm 20:09 <@matches> Oh boy, he's going to love what I did with the SVG and Postscript images... 20:09 <@matches> But I am glad I do not have to actually explain Bresenham's algorithm because it's actually annoyingly detailed 20:11 < sulix> All sane descriptions of Bresenham's algorithm end up being cascades of "By symmetry" anyway. 20:11 <@matches> I need to actually find a reference that applied Wu/Bresenham directly to a non-straight line 20:11 <@matches> You said Bresenham adapted his algorithm to circles but I don't think I'll bother unless someone adapted them to beziers 20:12 <@matches> Bresenham's paper on rasterisation techniques basically says "Compute some points close enough together and then just connect them with straight lines" 20:12 <@matches> But I think things might have advanced since the 1980s 20:12 < sulix> Well, we can compute points that are closer together and draw more lines, I guess. 20:13 <@matches> Next, Tim wants an example of a spline 20:13 <@matches> (Oh boy have I got that covered) 20:13 <@matches> My mathematics terminology on Beziers is not really great 20:14 <@matches> Well it's right but confusing maybe 20:14 <@matches> Or I just need to say "t is a trajectory parameter" 20:14 <@matches> Haha 20:15 <@matches> He found one of my "????" that is actually just me typing question marks and not a broken reference 20:15 <@matches> The *entire* section on shading and compositing has a big question mark 20:15 <@matches> Oh dear 20:15 <@matches> I just finished writing the compositing bit 20:16 <@matches> I hope the question mark means "Why isn't this written" and not "Why is this in here" 20:16 <@matches> Because it is quite useful for an excuse to say PostScript can't do alpha 20:17 <@matches> I need to refer to the IM (I really don't think that's a thing) and DOM when citing Hayes 20:17 <@matches> "I don't think Turing Completeness is essential" (Big cross through the Crippled Interpreted Model) 20:17 <@matches> Fair enough 20:17 <@matches> A tick appears 20:18 <@matches> Predictably in the web based documents part 20:18 <@matches> I need to explain why Ipython is cool if I want to talk about it 20:18 <@matches> My entire section on Precision as defined in the various formats is ? 20:20 <@matches> My still to be completed/started section on Graphics APIs, GPUs and Arbitrary Precision is three question marks and "How's all this going" 20:20 <@matches> The progress report gets a single tick 20:20 <@matches> And the references have similar issues 20:20 <@matches> Well 20:21 <@matches> I'll take a few minutes to quiver in terror 20:21 <@matches> But I think if I can just find a way to not sleep and still maintain productivity, I might be able to pull this off 20:22 <@matches> Interestingly he didn't call me out for just talking about standards 20:22 <@matches> But now I realise that's because I didn't have all the crap I've just written on standards in there 20:23 < sulix> It's going to be a long night, but I think we'll manage it. 20:23 <@matches> Mine will be too long but I don't care 20:24 <@matches> I'll ask for an extension to prepare a condensed version if I must :P 20:28 <@matches> It's kind of funny I've been spending more time making my vector image in SVG and PostScript nice than actually writing about either of those standards 20:50 <@matches> Argh the idea of making my koch snowflake example for PS just got in my head 20:50 <@matches> Which would be brilliant I guess if the topic was still "Fractal Document Formats" 20:50 <@matches> It probably would be useful if I could demonstrate precision issues.. 20:50 <@matches> NO 20:50 <@matches> MUST WRITE 20:50 <@matches> WORDS 20:50 <@matches> NOT PICTURES 20:51 <@matches> But still it would make the PostScript and SVG sections consistent with each other... 20:51 <@matches> NO 20:51 <@matches> Must control urge to put pointless pictures in 20:51 <@matches> No matter how much it seems like a good idea 20:51 <@matches> And not pointless 20:52 <@matches> Help I'm losing this battle 20:53 <@matches> It is probably actually a better way of making a Koch curve than the hideous Javascript parsing of strings version 22:50 <@matches> By the way, you can totally have "pre layout" stages in PostScript since you can define your own operators 22:50 <@matches> Or do I misunderstand your sentence 22:50 <@matches> Oh well it sounds smart anyway 22:51 <@matches> In fact it's a lot more concise than my DOM-y section 22:52 <@matches> I should sign my Lit Review as Captain Obvious 22:57 < sulix> My current version does have a "PostScript programs typically embody documents which have been type- 22:57 < sulix> set, though as a turing-complete language, some layout can be performed 22:57 < sulix> " sentence. 22:57 < sulix> by the document. 23:01 * sulix is still a little bit concerned about how he should reference things for their solutions to open problems rather than their contributions to standards. 23:03 <@matches> I think I am managing to do it 23:03 <@matches> I will commit something at some point 23:03 < sulix> I'm hoping that rewriting most of the rendering section with painful discussions of algorithms will do it. 23:03 <@matches> An example is Porter and Duff Compositing 23:04 <@matches> Because PostScript doesn't have alpha and I am really hoping that's just because Adobe had moved on to PDF by the time alpha was a thing 23:04 <@matches> And not because they thought alpha was dumb :P 23:05 <@matches> So I can relate Porter and Duff's model to the standards that do use it and say how it solves a problem that the standards that don't use it still have 23:05 <@matches> And then I can sit back in satisfaction 23:05 <@matches> And realise this says fuck all about precision 23:06 <@matches> But at least by talking about it, I have eliminated it from the set of things we need to worry about when talking about precision :P 23:06 < sulix> I've got a section which basically goes through all of the different document formats and looks at what their specs say about precision now. 23:06 <@matches> Yeah I have that, but it was dot-pointed 23:06 <@matches> I thought that would be OK actually but it has a question mark here... :S 23:06 < sulix> Basically most of them say "implementation-defined" anyway. 23:06 <@matches> Oh right because I was saying random stuff about how Postscript *used* to not have IEEE 23:07 <@matches> Yeah it is odd that the standards don't actually reference IEEE 23:07 <@matches> You'd think, since it's a standard... 23:07 <@matches> Instead they just say "single" or "double" or "it might be single if you're lucky but we don't care really" 23:08 <@matches> I assume "single" is widely accepted to mean IEEE single 23:08 < sulix> From my reading of the Postscript spec, it says basically "We've put IEEE here, but ask your printer manufacturer because they could be using anything for all we care." 23:08 <@matches> Ah I will check that more carefully 23:08 <@matches> But it sounds about right 23:08 < sulix> They give "typical limits" for their data types, but specifically do not specify what they are to be implemented as. 23:08 <@matches> I don't think I have the time to look at what PostScript did historically before IEEE-754 although it would be kind of interesting to know 23:09 <@matches> PostScript also does a bunch of silly maths because of units 23:09 < sulix> The idea being that each postscript interpreter could do whatever they liked. 23:09 <@matches> Cool 23:09 <@matches> I should know this already :S 23:09 <@matches> I just included a single character as a figure 23:10 <@matches> But I want to actually work out how to do it in LaTeX by setting the size of the font appropriately 23:10 < sulix> The PDF spec says pretty much the same thing, but notes that Adobe's implementation uses "Mostly IEEE singles" but "used to use 16.16 fixed point" and "still uses it for some things" 23:10 <@matches> I did see that 23:10 < sulix> TeX using 14.16 fixed point. 23:10 < sulix> DVI uses "up-to 32bit" signed integers. 23:11 <@matches> So basically no one actually uses IEEE for anything :P 23:11 <@matches> Good work 23:11 <@matches> I shall panic a bit and then try and actually do that work myself 23:11 < sulix> SVG uses "implementation defined" or "double-precision floating point" "for coordinate transforms" if you want to be certified "High Quality" 23:12 <@matches> I saw that one 23:12 <@matches> But I'm skeptical about how this plays with Javascript 23:12 <@matches> Not for High Quality even, just in general 23:12 < sulix> Javascript numbers are always IEEE 754 doubles. 23:13 <@matches> Ah thanks 23:13 < sulix> (Even their integers are IEEE 754 doubles, which just happen to be integers) 23:13 <@matches> Yes I have heard this before 23:13 <@matches> From you probably :P 23:14 < sulix> I don't have a source for that, and I'm not going to read the ECMAscript spec to find one, though. 23:16 <@matches> Oh right, Javascript is actually ECMAscript 23:16 <@matches> I forgot that 23:17 <@matches> Dammit I am struggling to stay awake here 23:17 <@matches> I'm not sure whether it's healthier to try to not sleep and give Tim a draft tomorrow and demand he read it in enough time to make last minute changes 23:18 <@matches> Or sleep and then be more coherant tomorrow 23:18 <@matches> I guess I'll try and finish a couple more sections 23:19 < sulix> I'm going to try to finish this tonight. 23:20 * sulix has another assignment due Friday that needs significant work. --- Day changed Thu May 22 2014 00:47 <@matches> So X just managed to totally shit itself 00:47 <@matches> Time to see when I last pressed Ctrl-S 00:48 <@matches> Oh good (I typically press it once per sentence) 00:48 <@matches> I hope it wasn't one of my SVGs that broke everything 00:49 <@matches> Making all my figures in SVG 00:49 <@matches> Lovingly hand written 00:49 <@matches> I'm not sure that was a good idea 01:43 <@matches> Heh, converting SVG to PS in Inkscape appears to introduce rounding errors of up to 0.1 of whatever unit PS is using 01:44 <@matches> 1.25*56 01:45 <@matches> Disregard I appear to have mistaken this terminal for a calculator 01:45 <@matches> They do look similar at this hour in the morning 01:49 < sulix> I'm seriously doubting whether starting to write stuff about how all of the rasterizing algorithms work was a good idea. 01:49 <@matches> Haha 01:49 <@matches> I don't really have much rasterising as such 01:49 <@matches> Straight lines 01:50 <@matches> Beziers aren't really "rasterising" so much as defining curves 01:50 <@matches> Then I mention fonts and how they are all bezier-ish 01:50 < sulix> I've just spent about an hour trying to prove that bresenham's algorithm can be made to not depend on any coordinates outside the screen. 01:50 <@matches> Then I have a bit on shading that I can't do 01:50 <@matches> :S 01:50 <@matches> That's probably not important 01:50 <@matches> To quote Tim in my thesis regards to actually explaining algorithms 01:50 < sulix> It turns out that if you clip the endpoints (even correctly), you adjust the slope of the lines slightly. 01:51 <@matches> "No you don't have space. [...] details should be left to where they are useful" 01:51 <@matches> Having said that absolutely none of this is "useful" 01:51 < sulix> To fix it you have to initialize bresenham's "accumulated error" properly. 01:51 <@matches> That sounds sort of relevant 01:52 <@matches> Well I just copied some SVG into PostScript and discovered that the coordinates are all reflected :S 01:52 < sulix> My choices for referencing this is either a textbook I don't have that "apparently mentions this" or a blog post which rants about it a bit. 01:52 <@matches> Bahaha 01:53 <@matches> That sounds like work for the final lit review rather than this one 01:53 < sulix> Still need to work out how to actually work in how my references solved problems rather than contributed to standards or whatever. 02:05 <@matches> minipage for latex is great by the way 02:06 <@matches> Like
but not awful 02:40 <@matches> Oh year 02:40 <@matches> The best spline curve example ever 02:41 <@matches> Fuck it took about 3 hours to do that 02:41 <@matches> Dear god 02:41 <@matches> Ergh remind me to go censor the log before Friday 1am 02:50 <@matches> I pushed my references changes by the way 02:51 < sulix> Yay merging! 02:51 <@matches> Oh I forgot the actual pdfs but whatever 02:51 <@matches> I am jealous of your actual concise and to the point lit review 02:51 <@matches> Mine suddenly exploded into figures 02:51 <@matches> I should stop 02:51 <@matches> I think I will delete the Shading section 02:52 <@matches> No wait it would be a gap to take it out now 02:52 <@matches> Argh 02:53 <@matches> I will just have to resist the urge to put a diagram in showing how shading works 02:53 <@matches> All these diagrams will probably kill me 02:53 < sulix> I'm thinking of scrapping chunks of the Rendering section of mine just so I don't have to finish them and can go to sleep. 02:54 <@matches> Tim did seem strongly in favour of covering the rendering stuff 02:54 <@matches> At least referencing the papers and giving the definitions of things if not actually how to render them 02:55 <@matches> Anyway I think Beziers at least are important 02:55 <@matches> I'm discovering a few interesting things about SVG 02:56 <@matches> The path definitions are basically exactly the same as postscript's commands except less stack-y 02:56 <@matches> But it has relative commands as well 02:56 <@matches> Which is interesting because if you have a really really long curve defined with relative commands 02:56 <@matches> Maybe, just maybe, it will actually cause a precision issue 02:57 <@matches> I doubt it though 03:00 <@matches> Well good luck, I am going to sleep 03:01 < sulix> Thanks. I will see what I can say about Béziers. 03:38 * sulix collapses. 08:07 <@matches> Nice work 08:07 <@matches> Mine is too detailed I think 08:07 <@matches> It's horrible because now I'm committed to following through on that level of detail everywhere 08:09 <@matches> Removing detail feels like murder 08:12 <@matches> Would you be offended if I cited your lit review as a "more concise" overview for the bored reader? :P 14:28 < sulix> So apparently the entire internet is talking about Bézier curves today. 14:28 < sulix> This would have been really useful, say, yesterday. 14:30 < sulix> Also this page looks amazing... http://pomax.github.io/bezierinfo/ 14:39 <@matches> Haha 14:39 <@matches> I think I've got the Beziers covered 14:39 <@matches> If you could just hop over to ratemylitreview and check me on that... 14:39 <@matches> :P 14:42 < sulix> Ratemylitreview has broken some of the equations... 14:46 <@matches> If I had time I would include a "rate ratemylitreview" field 14:46 <@matches> I sent an email 14:46 <@matches> Now to fear the wrath 14:47 <@matches> Half time 14:48 <@matches> Haha I'm somewhat regretting choosing such condescending ratings 14:49 < sulix> I got terrified seeing that email before I realised it was from you. 14:49 <@matches> Bahaha 14:49 <@matches> Well I have to give him something 14:50 < sulix> You should clearly make the ratings be all amazing, like: "Good, Great, Amazing, Truly Spiffing, Superlative and \"Everything in creation has been leading up to this page of my Lit review\"" 14:51 <@matches> You can POST your own ratings but expecting that might be a bit much 14:51 <@matches> They are emailed to me as text and they are also stored in the database as text 14:51 <@matches> Not the most objective of systems :S 14:51 <@matches> I thought the ratings covered all the bases though 14:52 < sulix> You could always do what the Shakespeare proramming lanugage does. Positive adjectives +1, negative adjectives -1. 20:18 <@matches> I haven't said half of what I thought I should about floats 20:18 <@matches> Tim has been scarily silent :P 20:19 <@matches> I guess I will assume that means everything is FINE 20:19 <@matches> I finally got my Table of Contents and things to not take up 6 pages 20:20 <@matches> I have to resist the urge to add some snarky comments to my section on LaTeX 20:22 <@matches> About how in theory you don't have to worry about where things go but in practice you spend hours doing horrible things like arbitrarily adding vertical space to force something into position because the anchor position doesn't take into account your line spacing and thus isn't where you expect and the next element overlaps things as a result 20:22 <@matches> Blargh 20:22 < sulix> Just stumbled upon a mention of numerical precision causing issues with Wu's algorithm in a book. 20:22 <@matches> Cite it 20:23 <@matches> Also give it to me to cite if I can stay awake long enough to read it 20:23 <@matches> You have contributed some good last minute references 20:23 <@matches> I seem to have contributed Javascript 20:23 <@matches> I should be ashamed 20:24 < sulix> It's in Abrash's Black Book, end of Chapter 42 ("Wu'ed in Haste; Fried, Stewed at leasure"( 20:24 <@matches> Haha 20:24 <@matches> My venerable graphics book doesn't even have Wu in it :S 20:25 <@matches> It also doesn't really properly reference people's papers, or I guess you don't need to in a textbook? 20:26 <@matches> It gives De Casteljau's method without crediting him for example. It does credit Bezier with things though. 20:26 <@matches> But they clearly didn't have to worry about putting \cite{} after every single statement 20:27 <@matches> I'm not sure how well my "I couldn't find a reference, have a look at my website" footnotes are going to go down 20:27 < sulix> Casey from the Jeff & Casey show did a video blog on Bézier curves and interpolation this morning. 20:28 <@matches> I really should start reading blogs more, but I was in no position to be watching blogs this morning 20:28 < sulix> He claims that Bézier did not invent the Bézier curve, so why the hell are they named after him. 20:28 <@matches> Had I known 20:28 <@matches> Oh he didn't 20:28 <@matches> I know that 20:28 <@matches> That's in Metafont 20:28 < sulix> I should read Metafont. 20:28 <@matches> They were named after him because he was the first guy that said "These look useful for things" 20:28 <@matches> However 20:28 <@matches> I can't find the paper in a peer reviewed journal 20:29 <@matches> I think it was for Industry (TM) 20:29 <@matches> And also in French 20:29 <@matches> I just cited a paper he did write in English about his experiences with Computer Aided Design 20:29 <@matches> He doesn't define anything, just shows pictures of nice bezier curvey car bodies 20:30 < sulix> I saw a bunch of french papers by him, but couldn't be bothered trying to work out which ones were useful. 20:30 <@matches> De Casteljau's paper is also hard to find 20:30 <@matches> The order of events was 20:30 <@matches> 1912 - Bernshtein comes up with the basis polynomials for some sort of mathematical fitting 20:31 <@matches> 1959 - De Casteljau decides to approximate the curves using his algorithm 20:31 <@matches> (De Casteljau is only an approximation by the way, but it would converge to the true bezier curve) 20:31 <@matches> 196? - Bezier does stuff 20:31 <@matches> 1983/4 - Knuth decides to use them for fonts 20:32 <@matches> Somehow they ended up in PostScript around that time as well 20:32 <@matches> Now we're stuck with them 20:34 <@matches> Hmm I hope my Tensor Equation is right there 20:34 < sulix> Here's that Wu thing, btw: http://www.jagregory.com/abrash-black-book/#notes-on-wu-antialiasing 20:36 <@matches> I'm struggling to make my floating point section sound sane 20:36 <@matches> Too many little details 20:37 <@matches> Like that you can choose different bases 20:37 <@matches> What even is a number anyway 20:38 <@matches> I think the proper way to approach it is talking about a number represented by digits and some numbers take infinitely many digits etc 20:39 <@matches> Then computers can only fit X binary digits in their registers 20:39 <@matches> A floating point is basically where you have a fixed point mantissa and then shift the location of the fixed point 20:39 <@matches> Let's try and ignore the implicit leading one... 20:40 <@matches> It sort of all falls apart when trying to fit IEEE in there 20:40 <@matches> This thing is too big as well :( 20:41 <@matches> Page limits are stupid 20:42 <@matches> I can't remember what it even is but it's definitely less than what I have 21:06 <@matches> Ah I see, the aliasing of Wu's line isn't perfect 21:06 <@matches> I think Wu admits that 21:06 <@matches> Hmm, that is interesting 21:11 <@matches> Argh that blog is all like "We should use web based documents instead of PDF" 21:11 <@matches> Pixels or Perish detected 21:11 <@matches> To be fair it does actually look nice 21:14 <@matches> The table of contents in the black book are quite amusing 21:14 <@matches> No! I finished writing about graphics stuff I need to do floating stuff 21:15 < sulix> It's a brilliant book, but possibly for another day. 21:16 <@matches> Dammit I guess I do need to produce more figures 21:16 <@matches> Sigh 21:17 <@matches> A picture is worth a thousand words and all that 21:17 <@matches> And therefore takes at least as long as writing a thousand words to make 21:27 <@matches> The more I look at SVG files the more convinced I am that they are actually the write way to do things 21:27 <@matches> right 21:28 <@matches> Despite all that philosophical guff, you can do the same things as postscript in similar ways, but you also have a DOM that isn't terrifying like whatever PDF supposely does 21:28 <@matches> I guess PDF would be more efficient though 21:29 < sulix> That's pretty much the conclusion I've come to. 21:31 <@matches> Unfortunately now I know more about SVG I keep hand editing my figures 21:32 <@matches> I don't need to use gnuplot's terrible data point markers anymore! 21:32 <@matches> I am free! 21:40 <@matches> I particularly like 21:40 <@matches> That I can make the points have alpha now 21:40 <@matches> So if you plot overlapping points it is no longer impossible to see them 21:40 <@matches> Of course we are restricted by the zoom in the pdf viewer... 21:41 <@matches> This project is too meta 21:41 <@matches> It is doing my head in --- Day changed Fri May 23 2014 11:22 < sulix> Welp. Submitting this version: http://davidgow.net/stuff/LitReviewDavid.pdf 11:23 < sulix> (The introduction has only got more over the top, I'm afraid) 11:48 < sulix> Do you know what is happening/isn't happening RE: Revised project proposals? 12:03 < sulix> Well: Literature review is submitted. 12:03 < sulix> (In person to the coordinator, which is a little bit scary) --- Day changed Sun May 25 2014 15:42 <@matches> No meeting tomorrow by the way 15:43 < sulix> Ah. Cool. I have like 300 things to do. 15:43 < sulix> Just pushed fixes for all of the compile warnings, btw. 15:43 <@matches> Cool 15:44 <@matches> I want to keep editing my Lit Review :S 15:44 < sulix> I had thought that Float() always returns a "float", but it sometimes returns a double. 15:44 <@matches> Oh 15:44 <@matches> Whoops 15:44 <@matches> Well a double is technically still a float... 15:44 < sulix> (Also, it turns out OpenGL actualy breaks the C++ spec, and is therefore impossible to use without hacks if you have -Werror enabled) 15:45 <@matches> Sigh 15:45 < sulix> It was warning that I was losing precision from float x = Float(blah); 15:45 <@matches> One of the things I want to put in my lit review is a snarky paragraph about how no one actually obeys standards anyway 15:46 < sulix> There are points where you get function pointers as void* pointers, but C++ needs to work on systems where code and data are stored in different bits of memory with different size pointers. 15:46 <@matches> On the other hand no matter how much better I make the lit review no one will read it because I'm being assessed on a conference paper not a dissertation 15:46 <@matches> Ah 15:46 < sulix> So casting any data pointer to a function pointer is apparently illegal. 15:47 <@matches> That's annoying 15:47 < sulix> Fortunately, gcc doesn't complain if you start the line that does it with "__extension__", so that's what we do. 15:47 <@matches> Haha 15:54 <@matches> Ok I am still about 3 days behind on sleep but I guess I should do work 15:54 <@matches> Bye --- Day changed Tue May 27 2014 12:49 <@matches> We missed the Computable Document Format (CDF) by Mathematica by the way 12:49 <@matches> Wolfram would be offended 12:50 * matches hopes none of the Mathematica fanatics read the lit review 12:50 <@matches> Or this channel 12:54 <@matches> I did have both Mathematica and IPython as a dot point and they got the mighty question mark of confusion over them 12:54 <@matches> Maybe I'll add them in later 12:55 <@matches> Frames does not seem to agree with my assertion that practically anything can be considered a document format :P 12:55 <@matches> Plain text! 12:57 <@matches> So I was looking through last year's Mech/Chem final year conference 12:57 <@matches> Naturally there is nothing remotely like this project in there 12:57 <@matches> :( --- Log opened Tue Jun 10 13:59:54 2014 13:59 -!- matches [matches@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 13:59 -!- Irssi: #ipdf: Total of 2 nicks [1 ops, 0 halfops, 0 voices, 1 normal] 13:59 -!- Irssi: Join to #ipdf was synced in 3 secs 16:29 -!- mode/#ipdf [+o matches] by OperServ --- Day changed Wed Jun 11 2014 13:13 <@matches> JVB just asked me if it was possible to have a self updating pdf 13:13 <@matches> I suppose he didn't ask whether it would be easy 13:15 <@matches> As in, one that would download itself if there was a newer version 13:16 <@matches> Technically with the crippled PostScript it would be "No" but with all that stuff in the standard about DRM and "Action Objects" and Javascript and stuff... 13:18 <@matches> Hmm, a webserver running git and a cronjob and requiring authentication may solve his problem 13:18 <@matches> With pdf.js or just relying on browsers to have pdf plugins 13:18 <@matches> Wait why am I solving JVB's problem --- Day changed Fri Jun 13 2014 16:31 <@matches> So exams have finished 16:31 <@matches> Well my exams have finished 16:32 <@matches> Now I can go back to panicking about the project again 16:37 <@sulix> Excellent: it's your turn to do something impressive for the meeting on Monday, then. :P --- Day changed Mon Jun 16 2014 14:49 <@matches> Some of this OpenGL stuff doesn't quite add up 14:49 <@matches> Like m_cahed_display.UnBind(); m_cached_display.Blit(); 14:50 <@matches> Oh 14:50 <@matches> I see 14:50 <@matches> There is a difference 14:51 * matches -> OpenGL documentation 14:53 <@matches> Right I see 15:03 <@matches> Well, this makes a lot more sense than tpg's "Adventures in VEMS" in #ucc at least 15:18 <@sulix> Well that's an achievement, I guess. 15:18 <@sulix> Also http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2431.pdf 15:18 <@sulix> It's the spec for "nullptr"... 15:20 <@matches> "Pointers are pretty cool. Pointers that are NULL are pretty cool. We address these issues by proposing nullptr" ? 15:21 <@sulix> Haha: Pretty much. 15:22 <@matches> Why not just reserve the word "null" 15:22 <@matches> I could get behind it then 15:23 <@matches> It is not a null reference 15:23 <@matches> But if you ever have a null reference something is horrifyingly wrong 15:23 <@matches> Bah humbug 15:24 <@sulix> They have a page about that where they said "everyone was naming their variables \"null\"". 15:24 * sulix realises he just escaped those quote. Oh dear. 15:24 <@matches> A valid point, which should have lead to "Everyone are morons" 15:24 <@matches> Fun fact 15:25 <@matches> Matlab (like fortran actually) will let you use key words as variable names. 15:25 <@sulix> "It's a feature!" 15:25 <@matches> Question on CITS2401 exam: "Why is 'ii' preferred over 'i' and 'jj' over 'j' for loop iteration?" 15:26 <@matches> Both i and j are the complex number sqrt(-1) 15:27 <@matches> It seems like naming it 'nullptr' instead of 'null' missed an opportunity to stop people naming their variables really confusing things :P 15:30 <@matches> Well I am infinitely wiser about nullptr now but I don't think it will stop me just using NULL 16:15 <@matches> This is slowly starting to make sense 16:35 <@matches> I'm having a bit of difficulty because it's all so optimised for the GPU 16:35 <@matches> I think what we need is an ObjectRenderer class or similar 16:36 <@matches> Have one for each type of object and implement RenderUsingGPU and RenderUsingCPU 16:36 <@matches> I will see what monstrosity I can come up with 16:36 <@matches> But a lot of that code for the circles and rectangles is exactly the same just copied and pasted with different variable names 16:37 <@matches> I think there is an official software engineering term for that sort of thing... 16:46 <@matches> Alright, breaking everything 16:46 <@matches> This will probably take a while 16:47 * matches dreads merges 17:02 <@sulix> Yeah, I was going to basically end up with an ObjectRenderer class, too. 17:02 <@sulix> So I'll leave it to you for now and procrasinate from doing my maths in some other way. 17:07 <@matches> Cool :) 17:52 <@matches> Now I'm not very strict about the whole RAII thing myself, but there seem to be some cases where things can probably just go in the constructor? 17:52 <@matches> I guess we can fight about those later 17:54 <@matches> I guess I can see us wanting to set m_render_inited to false and have it automatically recreate everything, maybe, but I can't see a case where we will want to recompile the shaders, so I am going to put the shader initialisation in the constructors 17:54 <@matches> I have gone mad with power 17:54 <@matches> Maaad 20:30 <@matches> This ObjectRenderer is like a two headed hydra 20:31 <@matches> I thought about using just the ibo and vbo and getting the indices out of it, but that's a bit terrible 20:31 <@matches> So it will have an ibo for the GPU and an array for the CPU 20:35 * sulix thinks this makes sense. 21:47 <@matches> Good news! I have things on the screen. Bad news. They are still on the GPU and they are wrong. 21:49 <@matches> More coffee required... 21:58 <@matches> Not sure if code wrong or fglrx having an existential crisis 22:04 <@matches> Unrelated to the segfaults of doom, but I just realised that there's all this interest in using GPUs for scientific computation, and everything seems to point to them having vastly inferior floating point computation to a CPU, which is a bit disconcerting 22:05 <@matches> I imagine the OpenCL libraries etc actually use the IEEE floating point capabilities? I hope? 22:05 * matches files under "beyond the scope of project" 22:06 <@sulix> If you commit code I can test it on non-fglrx if that'll help. 22:06 <@matches> I'd rather not commit it just yet, I am 90% sure it is something I have done wrong and don't want to shame myself by committing broken code 22:06 <@matches> It'd be like vomiting all over the codebase 22:07 * sulix is pretty sure half of his commits broke something. 22:29 <@matches> Ok I committed stuff that should in theory work with the test pattern again 22:30 <@matches> Using new and improved ObjectRenderer classes 22:30 <@matches> For some definition of improved 22:30 <@matches> It doesn't actually use the CPU yet 22:30 <@matches> It'll get there 22:33 <@matches> You can go and add your MandleBrotSetRenderer now though :P 22:36 <@sulix> Cool. 22:37 <@sulix> The circles do trigger that intel driver bug again, though... 22:38 <@matches> Ah damn 22:38 <@matches> Would making CIRCLE_FILLED the first ObjectType fix that? 22:38 <@sulix> It does. 22:38 <@sulix> (I just checked) 22:38 <@sulix> Yay intel! 22:39 <@matches> Haha 22:49 <@matches> Hey, does our rendering approach completely break compositing? 22:49 <@matches> Render all circles 22:49 <@matches> Then render all rectangles... 22:49 <@matches> There's no depth... 22:49 <@sulix> Um, maybe. 22:49 <@matches> :P 22:49 <@matches> I was just worrying about how to make compositing work using the CPU 22:49 <@matches> and then I realised it won't work using the GPU as it is either 22:50 <@sulix> If we're not doing alpha-blending, we could just add a z-coordinate and use the z-buffer. 22:50 <@sulix> Otherwise, they need to be sorted if they intersect. 22:50 <@matches> Let's not worry about this for now... 22:50 <@matches> Even though I spent a rather significant part of my lit review explaining how awesome compositing is 22:51 <@matches> I guess it doesn't matter, clearly the lit review was not intended for anyone to actually read 23:42 <@matches> I suspect RenderPixels doesn't work 23:45 <@sulix> This may be the case. --- Day changed Tue Jun 17 2014 01:05 <@matches> Behold the magnificence of CPU based rendering 01:06 <@matches> In which we pass a massive pixel array to the ObjectRenderer's and just save it to a BMP 01:06 <@matches> Because OpenGL 01:06 <@matches> I'll probably fix it later 01:11 <@matches> Whoops seg faults ahoy 01:12 <@matches> Wait I swear it wasn't segfaulting before I commited that 01:19 <@matches> It segfaults sometimes depending on where you have the view. If you just have one circle and zoom in you can see the amazingly less jagged looking lines. 01:19 <@matches> That, is a certified result 10:13 <@sulix> I got the CPU rendered version to show up on the screen. 10:14 <@sulix> RenderPixels was pretty broken. 10:38 <@matches> Nice 10:39 <@sulix> I think the segfaults are it trying to draw outside of the display. 10:39 <@matches> Yeah 10:39 <@sulix> I haven't managed to zoom in too much yet. 10:39 <@matches> My clipping is probably wrongish 10:40 <@matches> fonttex_frag.glsl? Fear 10:40 <@sulix> Yeah, the "basictex_frag" file did a bunch of pretty font-specific things. 10:40 <@matches> Ah 10:43 <@sulix> The CPU renderer also shows some random lines when there are no outlines on the screen. 10:43 <@matches> Is it just me or does it look slightly nicer on the CPU when zoomed out a bit 10:44 <@matches> Well it looks different 10:44 <@matches> I can't quite work out whether it looks nicer or worse :P 10:44 <@sulix> Okay, it doesn't segfault if the rectangle outlines are disabled. 10:45 <@matches> Ah 10:45 <@matches> Yeah it is setting top/bottom/left/right outside the pixels 10:45 <@sulix> I think there are just some slightly different edge-case rules when zoomed out. 10:47 <@matches> With my skills at writing renderers I should be working on the fglrx drivers 10:47 <@matches> :P 10:47 <@sulix> Things vanish if you zoom in too much, too. 10:48 <@matches> Blame it on floats 10:49 <@matches> The CPU renderer is using a width of 1 pixel less than it should be 10:49 <@sulix> Why are the floats sinking? :P 10:49 <@matches> That's unrelated 10:49 <@matches> It's probably an integer rounding issue somewhere 10:49 <@matches> When the view gets big something goes to zero 10:50 <@matches> The CPU renderer transforms everything to pixel positions and then renders using those 11:02 <@matches> The GPU renderer occassionally leaves off the corners of things 11:02 <@matches> I never noticed before 11:02 <@matches> Anyway I think the segfaults are fixed 11:03 <@matches> Looking at the mysterious disappearances next 11:04 <@matches> It's integer overflow! 11:04 <@matches> Facepalm 11:05 <@sulix> Is it int64_t time? 11:05 <@sulix> Or magic huge bigint time? 11:05 <@matches> No I don't think that's necessary 11:06 <@matches> If the transformed width is smaller or larger than the width of the screen you can surely just ignore it 11:06 <@matches> Well, depending on what you are drawing 11:08 <@matches> Well it does matter unless you do some clever maths 11:08 <@matches> The clever maths was your part of the project... 11:09 <@matches> So I will just make them int64_t for now 11:50 <@matches> Pushe 11:50 <@matches> *d 11:50 <@matches> I should probably just make all the coorinates into Real instead of int64_t actually 12:03 <@sulix> Wow: this is pretty awesome. 12:03 <@sulix> I still get the artefacts, but I have to zoom in a lot more. 12:03 <@matches> Haha 12:04 <@sulix> Also, the CPU rendering artefacts and the GPU rendering artefacts are pretty similar on my machine, so it looks like it's just precision causing them. 12:04 <@matches> That is nice 15:20 <@matches> I'm trying to do a performance graph. Gnuplot doesn't like it much 15:20 <@matches> Well actually it's python's crappy interface to gnuplot that doesn't like it 15:23 <@matches> ... tempted to implement the performance graph in ipdf... 15:23 <@matches> Just keep adding circles to the document 15:24 <@matches> So meta 15:25 <@matches> We need a cool performance graph-y thing 15:26 <@matches> I think doing it in OpenGL is going to be the least shitty way actually 15:26 <@matches> This is a wheel that's probably been invented but it was invented wrong 17:11 <@matches> I've got a performance graph sort of working 17:11 <@matches> It almost looks like we are doing real science! 17:13 <@matches> I think we'll need to put some effort into our data analysis though because it's extremely noisy 17:13 <@matches> Smoothing averages or something 17:13 <@matches> Smoothing averages are the best 17:14 <@matches> They make any data look amazing 17:15 <@matches> Anyway, CPU rendering is only worse than GPU rendering when you force re-rendering 17:16 <@matches> So well done with the amazingly efficient cached frame buffer 17:18 <@matches> We can probably make it draw every frame both on the CPU and GPU to compare them in real time 17:18 <@matches> The possibilities are limitless! 17:19 <@matches> Graphs graphs graphs! 17:20 <@matches> Also I did end up using Gnuplot and python (sorry) but I made it slightly less shitty 17:27 <@matches> I have pushed things 17:27 <@matches> Also we probably don't need all three of those ways to measure performance 21:00 <@sulix> I got the graphs working on my laptop: very nice. 21:00 <@sulix> I can see how more GPU time is used with GPU rendering and more CPU time with CPU rendering quite well, actually. 21:59 <@matches> So the objects all being in one structure of arrays is sort of inconvenient because the size of objects has to be constant 21:59 <@matches> Also the size of Real has to be constant 22:03 <@matches> I guess we could have union {Rect rect, Bezier bezier} and do rectangles and Beziers in the same thing but that is slightly terrifying 22:04 <@matches> But there's still the problem of Real because as soon as Real becomes arbitrary precision it will start allocating memory and not be fwrite/fread'able 22:04 <@matches> :S 22:05 <@matches> You'll still want the struct of arrays because that will make view reparenting much easier 22:05 <@matches> Gah 22:06 <@sulix> I'm tempted to just split it by type: Have an array of Rects, an array of Béziers, an array of Circles, etc. 22:06 <@matches> Yeah but you need to store an "indexes" array as well 22:06 <@matches> But that might be the least terrible 22:07 <@matches> Yes that should work 22:07 <@matches> Our fwrite/fread is still doomed though 22:07 <@matches> When shit gets Real 22:07 <@sulix> Yeah, you'd need some indices one way or another. 22:08 <@sulix> And yeah, we'll need a massive "ConvertWhateverRealIsStoredInTheFileToWhateverRealIsDefined" function or something. 22:08 <@matches> That will totally be its name 22:08 <@sulix> (Some old compilers had function name limits... I wonder if modern gcc has) 22:09 <@sulix> (There is but one way to find out!) 22:09 <@matches> We don't need an array of circles/ellipses since we get those for free with Rect. Unless you want circular arcs as well as bezier curves 22:10 <@matches> Which you probably will? So you can approximate beziers 22:10 <@matches> Anyway I'll worry about adding Beziers first and once we've worked that out others should hopefully be easier 22:11 <@matches> I was sort of thinking it would be good to be able to define groups of objects as a special object type 22:11 <@matches> Then you can make paths out of your beziers 22:11 <@matches> But they won't be fixed size 22:12 <@matches> Anyway I will see if you have magically solved the problem for me in the morning :P 22:14 <@sulix> I wouldn't count on it... --- Day changed Wed Jun 18 2014 16:50 <@matches> Behold, the glory of Beziers and Bresenham! 16:50 <@matches> Breseniers I shall call them 16:54 <@matches> I'm getting a very strong vibe of "Reinventing graphics technologies from the 1990s" at the moment 16:55 <@matches> I should probably look at floating point some more 16:55 <@matches> And reinvent numerical computation technologies from the 1980s 16:56 <@matches> We need a GPU renderer for the Beziers, and we need to fix save/load to not assume everything is a fixed size, and ... 16:56 <@matches> Argh 16:56 <@matches> All the things 17:00 <@matches> Maybe I'll multithread the CPU rendering too, just to make things more difficult :P 22:48 <@sulix> So I got some béziers rendering on the GPU. 22:48 <@sulix> They're not the ones in the document, and they're not in the right spots, though. 23:12 <@sulix> First 3 béziers are rendering properly on the GPU, then we get corrupted memory or something. 23:14 <@sulix> Ah: I see, I need some way of uploading which bézier IDs are being used. 23:41 <@sulix> Okay, Béziers now render on the GPU as well. 23:43 <@sulix> The code is a little bit ugly, and for that I am sorry, but blame the fact that the GL feature that makes this nice is only about a year old and so nothing supports it. 23:43 <@sulix> So we're basically uploading all of the raw document data into a huge texture. 23:47 <@sulix> (If you ask me, the GPU ones also look slightly nicer, though that's probably a bug) --- Day changed Thu Jun 19 2014 13:55 <@matches> From those papers I was under the impression just rendering a bezier on a GPU was an impressive feat, so well done :P 13:57 <@sulix> (It's basically just a direct port of your CPU implementation, tbh) 13:59 <@matches> When I zoom out the GPU ones look nicer, there's probably something wrong with my Bresenham implementation 13:59 <@matches> Although it was mostly shamelessly copied from "Computer Graphics" 13:59 <@matches> Except they were like "Here it is for 0 < m < 1, the rest can be done by symmetry" 14:02 <@matches> The lines definitely have gaps on the CPU, and they also seem too thick as you zoom out 14:02 <@matches> Having said that, I don't think the GPU starts at x0,y0 14:03 <@matches> Anyway I'm going to implement a Rational number type and see if anything exciting happens (that's how you do research right?) 14:06 <@matches> Fortunately I sort of did most of this for one of the codejam problems (where it turned out I didn't really need Rational numbers but I thought I did) 14:20 <@sulix> Fixed the missing bit off the end. 16:43 <@matches> I suspect Rationals are either not a very good idea, or there is a bug in one of my fundamental operations 16:43 <@matches> +, -, *, / are hard 16:56 <@sulix> Is it at least a pretty bug? 16:59 <@matches> Um... 16:59 <@matches> No 17:00 <@matches> It seems buggy for anything other than the {0,0,1,1} starting view 17:14 <@matches> I suspect it's the expf in the mouse wheel scrolling 17:14 <@matches> Since you know, exp is definitely not a rational number... 17:15 <@matches> Hmm, but it shouldn't matter because it will just convert to the nearest rational number 17:16 <@matches> ie: p = (int64_t)(whatever*1e10) q = (int64_t)1e10 17:28 <@matches> Oh 17:28 <@matches> Oh 17:28 <@matches> Head -> Desk 17:28 <@matches> Rational & operator*=(const Rational & r) {this->operator=(*this*r); return *this;} 17:28 <@matches> Rational & operator/=(const Rational & r) {this->operator=(*this*r); return *this;} 17:29 <@matches> Rational & operator-=(const Rational & r) {this->operator=(*this+r); return *this;} 17:29 <@matches> I think the worst part is that I actually said "It is probably a bug in my +,-,*,/ 17:29 <@matches> And it still took me this long to notice 17:30 <@matches> The second worst thing is I've made that sort of mistake like 1000 times before 17:30 <@matches> The third worst thing is I am recalling that article where the guy says "At least plus and times are sort of the same thing" 17:30 <@sulix> Feel the power of copy and paste flowing through you. 17:32 <@matches> Well let's not celebrate just yet, the view still goes to shit. Just slightly slower :P 17:33 -!- matches changed the topic of #ipdf to: NaNpdf 17:33 <@matches> Our document supports a view of {-inf,-inf,nan,nan} thus making it truly infinite precision 17:34 <@sulix> I had that happen a lot when I was writing the original zoom code. 18:19 <@matches> So I suspect that Rationals are just a really shitty number representation :P 18:20 <@matches> Specifically, you get integer overflows really really fast 18:20 <@matches> And if you are going to have a Rational that's BigInt / BigInt you may as well just have a BigFloat 18:21 <@matches> The ancients were probably right. 18:21 <@matches> When they decided not to use rationals. 18:23 <@matches> I guess floats are rationals technically, I mean the representation using P/Q 18:23 <@matches> I kind of wish I'd done some pure maths here... 18:23 <@matches> Or paid more attention in second year 18:28 <@matches> At least I sort of have conclusive evidence that rationals suck. As opposed to "it should be obvious to anyone with half a brain" 19:00 <@sulix> Floats are not rationals. 19:00 <@sulix> Not exactly. 19:01 <@sulix> Something which can be stored in a finite amount of space as a rational cannot always be stored in a finite amount of space as a float, but not vice-versa. 19:01 <@sulix> e.g.: 1/3 19:04 <@sulix> Basically floats = rationals where the denominator must be a power of two. 19:05 <@sulix> (Of course, these are all the same in the limit, but the limit of a cauchy sequence of rationals gives the reals, so the point is kinda moot, there, anyway) 19:18 <@matches> Yeah floats are a subset of the rationals I think I meant --- Day changed Sat Jun 21 2014 16:22 <@matches> So I got a new smartphone today... I'm having fun trying to zoom in on things 16:24 <@matches> Actually the zooming isn't annoying so much as the needing to pan around to view all the text in a pdf 16:25 <@matches> This is what I get for buying the cheapest phone with the lowest resolution they had :P 16:26 <@matches> I didn't want to get one more expensive than my old one because I'm still convinced I will get around to fixing it one of these days 16:26 <@matches> Or months. Or years. But eventually. --- Day changed Mon Jun 23 2014 11:51 <@matches> The meeting happened at ~11:30 12:49 <@sulix> Oh damn. I thought there wasn't going to be one today. 12:49 <@sulix> What did I miss? 13:04 <@matches> Basically I told him what we'd done 13:05 <@matches> Which was rendering on CPU or GPU, and Beziers (but only degree 2) 13:06 <@matches> And I implemented Rationals but they are terrible, so he sent me some code from an ACM competition about approximating things with Rationals 13:13 <@sulix> Some javascript guy is trying to convince people that the only numeric data type should be some custom 64-bit decimal thing. 13:13 <@sulix> A lot of people have started quoting Kahan at him. 13:20 <@matches> Haha --- Log closed Tue Jun 24 16:07:29 2014 --- Log opened Tue Jun 24 16:17:39 2014 16:17 -!- matches [matches@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 16:17 -!- Irssi: #ipdf: Total of 2 nicks [1 ops, 0 halfops, 0 voices, 1 normal] 16:17 -!- Irssi: Join to #ipdf was synced in 15 secs --- Day changed Wed Jun 25 2014 21:41 < matches> So... if we need to put a HTTP server in IPDF I've got us covered... 21:44 <@sulix> You terrify me. 21:45 < matches> I still have to work out Websockets 21:45 < matches> They are silly 21:46 <@sulix> I take it they aren't compatible with regular sockets. 21:46 < matches> Well you use a TCP socket, but they aren't just plain text 21:46 < matches> There's a protocol on top of it 21:46 < matches> It's wired 21:47 < matches> *wierd 21:47 < matches> There are frames and things 21:47 < matches> And copious amounts of base64 encoding the SHA1 hash of a string prepended to a magic string 21:48 < matches> Apparently this makes it more secure 21:48 * sulix looks doubtful. 21:48 <@sulix> I could understand it being more secure if they actually encrypted things. 21:48 < matches> They have wss:// as well which is just the same thing through ssl 21:48 < matches> Yes it doesn't make sense 21:49 <@sulix> But plain "boring" TCP has been used since (I am assured) the beginning of time and there are still one or two things that use it which are not currently being hacked into. 21:49 < matches> Haha 21:49 < matches> I'd like websockets so I can control my robot via my phone through its web browser... 21:50 < matches> I can probably do that without websockets but it will also be useful for humphrey the rabbit 21:50 <@sulix> Surely with plain old TCP you could control your robot via telnet, which is more awesome and just as user friendly. 21:51 < matches> :P 21:51 < matches> It will have a webcam image though 21:51 * sulix mutters "ASCII art" under his breath. 21:52 < matches> I figure if I implement everything in C++ it will be less "Webby" 21:52 < matches> And more segfaultastic 21:52 * sulix has a new favourite word. --- Day changed Thu Jun 26 2014 14:58 < matches> I think the WebSocket RFC put this "Framing" business in just to confuse people 14:58 < matches> My RFC Compliant* WebSocket server just sends the entire message in a single frame 14:59 < matches> Doesn't TCP already do framing or something 15:00 < matches> I mean, they specifically allow for frames with up to 2^63 bytes 15:00 < matches> Sorry, bits not bytes 15:02 < matches> So server -> client is pretty much TCP but you stick some stupid frame guff on the message 15:02 < matches> client -> server involves... "masking" 15:02 < matches> There are several long paragraphs on it 15:10 < matches> I'm going to pretend this is related to precision --- Day changed Wed Jul 02 2014 17:30 < matches> I put the code repository on github 17:32 < matches> This is where a more hip and cool person would say something like "#yolo" but I prefer to wonder how I got 26K of lines and you have 65K... 17:32 < matches> "How many lines of code does it take to draw a rectangle?" 91000 --- Day changed Fri Jul 04 2014 12:59 < matches> Found my rational bug 13:00 < matches> ... 13:00 < matches> Copy paste strikes again 13:00 < matches> My operator/ looked suspiciously similar to operator+ -_- 13:00 < matches> -____- 13:02 < matches> Not sure how it got like that, it was definitely working at one point 13:02 * matches should probably use git properly 13:12 < matches> Pushed it 13:21 < matches> So yeah, it should work fine until you zoom 13:21 < matches> Then crazy things happen 16:44 < matches> I think all the references you added at the last minute break my litreview 16:45 < matches> (he says several months later :P_ 21:00 <@sulix> Question: in Rational::Simplify(), why is (-P)/(-Q) becoming (-P)/(Q) rather than P/Q? 21:01 <@sulix> Shouldn't P = -P here? http://git.ucc.asn.au/?p=ipdf/code.git;a=blob;f=src/rational.h;h=41cce09078b4e96eb17a6bb6e28478ea64637b57;hb=HEAD#l74 21:02 <@sulix> Also zoom can be improved (but not totally fixed) by reducing precision when overflow would be possible. 21:19 < matches> Yeah, that's the idea of using the Stern Barcot tree Tim was talking about 21:20 < matches> Which I still need to read about 21:20 < matches> Also yes P should be -P because I am just that amazing at maths 21:22 < matches> In other news assembly happened 21:22 < matches> http://git.ucc.asn.au/?p=ipdf/code.git;a=blob;f=src/tests/add_digits.s 21:22 < matches> Which no doubt has terrible bugs in it :P 21:23 < matches> It was a bit confusing how passing and returning arguments with x64 was completely and utterly different from x86 and almost every tutorial is from at least ten years ago talking about x86 21:24 < matches> x64 is actually much easier though 21:25 < matches> At least, I think they are different, I didn't have to mess with the stack which seemed to be a thing with x86 and also that motorolla language we used in first year 21:25 < matches> Just got all the arguments in a bunch of registers 21:31 <@sulix> I think I just worked out why you have 16 "inc" instructions, and am loving it! 21:32 <@sulix> inc doesn't change flags! 21:32 < matches> I wonder if it would be faster to just store the carry flag in a register though 21:33 < matches> Actually probably not because there'd be branches involved 21:33 < matches> Hmm 21:33 <@sulix> Traditionally, mucking about with flags is slow. 21:33 < matches> Yep cool 21:34 < matches> I've got the AMD64 ABI 21:34 < matches> Chapter 2 is a good one 21:34 < matches> "Software Installation" 21:35 < matches> "This document does not specify how software must be installed on an AMD64 architecture machine" 21:35 < matches> End chapter 21:35 <@sulix> Just a thought, can use use the lea instruction instead of all of those incs. 21:37 <@sulix> Like lea rsi, [rsi+8h]? 21:37 * sulix ponders. 21:38 < matches> Maybe, my assembly is very rusty and was based on those ELEC1301 labs in the first place... 21:38 < matches> I don't even remember if they had lea 21:39 <@sulix> (Also I just got a message from KDE: "could not launch a process. perhaps you have reached the limit of running processes") 21:39 < matches> :S 21:40 < matches> When did you last reboot? 21:40 <@sulix> This morning, actually. 21:40 < matches> Integer overflow in PID? 21:40 <@sulix> It looks like it was an out-of-memory problem. 21:40 <@sulix> On a related note, the intel instruction set documentation is a 3 and a half thousand page pdf. 21:41 <@sulix> and firefox has a PDF viewer written in javascript. 21:41 <@sulix> ...that runs by default. 21:44 < matches> Hahaha 21:44 < matches> Yes, pdf.js is apparently the best thing since sliced bread... 21:45 < matches> I'm having some difficulty with lea, possibly the syntax 21:47 < matches> "lea (%rsi+8), %rsi" is wrong 21:48 <@sulix> Yeah, gcc's assembler uses whacked syntax. 21:48 < matches> I thought it was just () instead of [], add % to all the registers, and swap destination and source 21:48 <@sulix> http://git.ucc.asn.au/?p=ipdf/code.git;a=blob;f=src/tests/add_digits.s;hb=HEAD 21:49 <@sulix> They replaced the arithmetic operators with strange things, too. 21:49 < matches> Riight 21:49 < matches> Thanks 21:49 < matches> So 8(,%rdi,1) means [rdi+8] 21:49 < matches> That is dumb 21:49 <@sulix> I'm not sure if it's worth using nasm or the ".syntax intel" directive. 21:51 < matches> Hopefully there won't be too much more assembly to write... 21:51 <@sulix> Technichally lea (and other memory addressing instructions) take the form "[register+register*(1,2 or 4)+(number)]" in intel and "number(%register,%register,(1,2 or 4))" 21:51 <@sulix> in gcc 21:51 < matches> ok 21:51 < matches> Well once I know the syntax I can cope with it 21:51 < matches> But all the documentation being written in a different syntax doesn't help :P 21:52 <@sulix> Yeah, there are a lot of people who hate gcc syntax, which was an (unsuccessful) attempt to make assembly for different machines more consistent) 21:52 < matches> I decided to go with it because I vaguely remembered your commander keen patches looked like they were in gcc syntax :P 21:53 <@sulix> Hah: they were in "ckpatch" syntax. 21:53 <@sulix> And were just the final output bytes. 21:53 < matches> The memory can play strange tricks... 21:54 <@sulix> I used the "debug.com" utility that came with dos to assemble them, which let you write assembly to arbitrary memory. 21:54 <@sulix> and then read the contents of that memory to see what it assembled down to. 21:55 < matches> So, I need subtraction and multiplication but not division to implement arbitrary rationals 21:55 < matches> I'll try sort those out tomorrow 21:56 < matches> I'm pretty sure I'm doing better than at least one arbitrary integer representation 21:56 < matches> Which had a int32_t word and int64_t "double" word 21:56 < matches> So they could tell if they had a carry by doing the additions using double words 21:57 < matches> The code in C was longer than add_digits is in assembly 21:57 < matches> Although to be fair it might actually work on things that aren't amd64 21:57 <@sulix> Well, the good news is that there's an "sbb" instruction like "adc" 21:57 < matches> Excellent 21:58 <@sulix> The bad news is that multiplication is harder. 21:58 < matches> Yeah, at least I don't need division though 21:59 < matches> Although converting it to a string will be annoying 21:59 <@sulix> IIRC, the IMUL instruction gives an output twice as long as the inputs, to prevent overflow. 22:00 <@sulix> Converting to a string won't be so bad if you get division done. 22:00 <@sulix> And you can always just implement multiplication and division by slow recursive addition/subtraction. 22:03 < matches> There's a bunch of papers on number representations that use things that aren't floats or rationals from a quick look 22:04 < matches> I guess I just need to implement as many things as possible and compare them all 22:04 < matches> Seems easy enough... 22:04 < matches> (Famous last words) --- Day changed Sat Jul 05 2014 11:09 < matches> Well... subtraction took me two seconds 11:09 < matches> Should probably have just done it last night 11:09 < matches> I got distracted 11:09 < matches> By someone actually using my websocket library 11:09 < matches> Does this mean I'm officially an open source developer now 11:09 < matches> I didn't even give it a license :S 11:11 < matches> Hmm 11:12 < matches> Multiplication... 11:12 < matches> It is tempting to just use a for loop and call the += operator... 11:40 < matches> I'll do that for now I think 11:41 < matches> Once += actually works 11:41 < matches> Turns out I will definitely need division also 11:42 < matches> I was looking at the rationals going "There are no divisions here!" 11:42 < matches> But there are 11:42 < matches> In the gcd 11:42 < matches> Mind you maybe I don't need to call gcd if I have arbitrary integers :P 11:42 < matches> Just use all the memory 12:39 < matches> Ok for loop for multiplication is not easy 12:39 < matches> Bah 12:39 < matches> Having to actually learn assembly properly 12:40 < matches> I mean I could use a for loop but it would have to use an Arbitrary integer and take a very long time... 12:47 <@sulix> There's no need to have a for loop index > 64bit because there will never be enough memory for an integer that big. 12:47 < matches> True 12:54 < matches> Putting "_asm" in filenames so that our Makefile can do the .s files is kind of irritating 12:54 < matches> Would naming them .cpp work? That would be even more irritating though! 12:54 < matches> Oh well it compiles 12:58 < matches> I bet it turns out 128 bit integers would have been more than sufficient for any zoom range people could feasibly get to by scrolling 13:15 <@sulix> I'm told 256-bit integers can represent the visible universe to the width of a proton or something. 13:45 < matches> I might put a maximum length in once this works 13:45 < matches> So I'm not doing a Java 13:46 < matches> Where 1/3 becomes "Runtime Exception!" 13:46 < matches> That's with BigDouble not BigInt but whatever 14:00 < matches> I must admit, assembly is pretty nice for this sort of thing 14:00 < matches> At least, the inner operations 14:00 < matches> Not for managing the memory 15:29 < matches> Alright. We have an Arbint class that is equivelant to an int64_t when it only has one digit. 15:30 < matches> I'm not sure how to test that extra digits function correctly 15:30 < matches> Other than just looking at a few cases and going "Yep that looks right" :S 16:40 < matches> Well... somewhere along the way I lost kcachegrind and now I seem to have to run dist-upgrade to get it back 16:41 < matches> Currently 10% of the way through upgrading tex-live... 16:41 < matches> The mystery of just how shitty the Arbints are will have to wait 16:42 < matches> Well it's clear they are shitty but I suspect there is a bug in division 16:42 < matches> Maybe I should actually read my code 16:42 < matches> Blargh 16:47 < matches> Ok constructing a rational takes infinite time 16:51 < matches> Ah, 1 % 1 == 1 16:51 < matches> That is definitely not correct :P 17:56 < matches> Oh my goodness I just rendered a frame 17:56 < matches> On the GPU... 18:00 <@sulix> Hmm... {add,sub}_digits_asm.s are missing from git. 18:05 < matches> Really 18:05 < matches> Whoops 18:07 < matches> There you go 18:07 < matches> Addition, subtraction, multiplication should be fine, I need to actually do division properly 18:08 < matches> Also probably pow at some point 18:08 < matches> Since pow still just casts things to doubles 18:22 <@sulix> It works! 18:22 <@sulix> (Eventually) 18:24 < matches> Haha 18:24 < matches> Of course it's still in the single digit range 18:24 < matches> Or did you manage to wait long enough to zoom a bit 18:25 < matches> I'm sure I can make this division better if I use some kind of binary searchish type algorithgm 18:25 < matches> I could look up the proper algorithm too I guess 18:25 <@sulix> Yeah, I was thinking binary search. 18:26 <@sulix> You'd want a decent bitshift implementation. 20:32 < matches> Yeah it is more difficult than I thought 20:33 < matches> I'm going to need "shift_digits" assembly functions 20:33 < matches> C style bit shifting has too many wierd edge cases 20:36 < matches> 0x7000000000000000 >> 3 == 0x0e00000000000000 ? 20:36 < matches> There are more bits set in the second number than the first! 20:38 < matches> And unlike multiplication where it fills an extra register for you, you just lose the extra bits with shr and shl :S 20:39 < matches> Except for a carry 20:39 < matches> So I'd have to do a loop one bit shift at a time 20:39 < matches> Blergh 20:40 < matches> I shall resume my epic battle with primary school level mathematics tomorrow --- Day changed Sun Jul 06 2014 00:32 <@sulix> long division of an arbint by a uint64 worksish. 09:47 <@sulix> long division of an arbint by a uint64 now actually works and is less obviously badly designed 10:32 < matches> Thanks... 10:33 < matches> In other news I seem to have broken X again 10:34 <@sulix> Oh no! 10:35 < matches> We need an ASCI renderer... 10:36 <@sulix> That can not possibly end badly. 10:40 < matches> shouldn't be too hard... 10:40 < matches> Lets see if reinstalling fglrx works 10:41 < matches> I need to add that to a boot script :S 10:42 < matches> uhoh installation failed 10:48 <@sulix> Hmm... enabling optimization makes Arbint segfault. 10:49 < matches> You should probably make quadtrees 10:50 < matches> Although I admit you're better at Arbints than me :P 10:50 <@sulix> Yeah... I should. 10:50 <@sulix> But segfaults... 10:51 < matches> Yeah somewhere in std vector I had some as well 10:51 < matches> I think I might change to a custom dynamic array 10:52 < matches> Then fast copying is easier 10:52 <@sulix> Yeah, it's segfaulting in std::swap somewhere, I think. 10:52 < matches> I'll fix it when I have X 10:53 < matches> Or an ascii renderer... 10:54 < matches> Probably more realistic at this stage 10:55 <@sulix> I'm pretty certain there's a unicode character for "face of disapproval due to fglrx bugginess". 10:56 < matches> Yeah but when you try and render it you get a seg fault 11:24 < matches> Woo, xvesa 11:26 < matches> I see what you mean about fglrx being hard to remove 11:58 <@sulix> So: quick profile. 98% of frame rendering time is spent in Arbint::Division. 11:59 < matches> Yeah 12:00 < matches> I *was* trying to install kcachegrind you know 12:00 <@sulix> The vast majority of that time is spent in malloc and free. 12:01 < matches> Well copy constructing an Arbint requires copy constructing the vector 12:01 < matches> I'll investigate 12:01 < matches> Now I have X again 12:01 < matches> Go make a quad tree 12:02 <@sulix> Also, should add_digits clear the carry flag at the beginning? 12:02 < matches> Hmm 12:02 < matches> Probably 12:02 < matches> Yeah 12:09 < matches> I suspect having a copy-on-write Arbint won't help as much as having a non-terrible division algorithm so I'll try fix that first 12:09 < matches> But copy-on-write Arbint shouldn't be too hard 12:09 < matches> Oh unless the original changes 12:10 < matches> Yeah it would be hard 12:10 < matches> I'm sure I did something like it before 12:10 < matches> Back when I actually made my own data structures instead of just using std::vector 12:15 <@sulix> My custom vector class: http://davidgow.net/stuff/DynamicArray.h 12:15 <@sulix> Probably won't compile without a bunch of other files, though. 12:16 < matches> I think I have several, in different versions of neurosis 12:16 < matches> Which was never under git 12:16 < matches> Some of them were prone to segfaults though 12:17 < matches> So, will you have some kind of quad-tree-y thing by monday? :P 12:17 <@sulix> Mine works, but doesn't call constructors or destructors, so it's only really useful for ints/floats/pointers or structs thereof. 12:18 <@sulix> I have a "struct QuadTree". 12:18 <@sulix> (You can't do anything with it, but the basic idea is there) 12:20 < matches> My shifting operators might not have been as fith as I thought last night 12:20 < matches> Since 7 and e do actually have the same number of bits 12:21 < matches> I'm not sure where that came from 12:21 < matches> Ah dammit 12:21 < matches> Cannot find -lGL 12:22 <@sulix> Try just removing that from the Makefile 12:22 <@sulix> I think when I GL-3'd everything I made it load libGL at runtime. 12:23 < matches> Well it will compile but I get glx errors 12:23 < matches> I get similar errors running glxinfo though... 12:24 < matches> Odd 12:26 <@sulix> I think you still have some of fglrx breaking things. 12:26 <@sulix> It replaces the system libGL.so 12:26 < matches> I installed mesa's stuff 12:27 <@sulix> You need to also get the version of libGL that runs as part of the X server, IIRC. 12:28 < matches> I'll try some apt-get --reinstalls 12:29 < matches> I think most of my problems were that debian was going "You don't have a graphics driver, here, have one" and then things were breaking and reinstalling fglrx would give me graphics but leave me with a partially installed debian driver as well :S 12:30 < matches> Well ok 12:30 < matches> most of my problems were fglrx 12:30 <@sulix> I remain sceptical that installing fglrx by hand will ever cause anything that is not pain. 12:30 < matches> Well it worked better than the open source drivers for a very long time 12:30 < matches> It all ended in tears and segfaults though 12:32 < matches> Also it worked better than the non-free fglrx package in the debian repos which always ended in tears and segfaults 12:33 <@sulix> I use the non-free nvidia package, which works fine, even if it is horribly outdated. 12:34 <@sulix> I'm scared of the sheer amount of ripping up the rendering code getting quadtrees working will take. 12:39 < matches> Haha 12:40 < matches> It might be easier to do the CPU rendering in quad trees first? 12:40 < matches> I'm not quite sure how you'll do it 12:41 < matches> CPU rendering at least gives you direct control over the rendering target as a pixel buffer 12:41 < matches> GPU rendering is a bit shady (ho ho) 12:41 <@sulix> ... 12:42 <@sulix> That was terrible, yet accurate! 12:42 < matches> With the CPU rendering we're already passing the objects list, view, and target bounds 12:42 < matches> So maybe you can adapt View or something to be quad-tree-ish 12:43 < matches> Good luck 12:44 <@sulix> Yeah, the current plan is to adapt the rendering stuff to accept a "first object id" and "last object id", and then only render those. 12:47 < matches> Hmm, you could call RenderUsingCPU with a different target pixel buffer for each part of your quad tree or something 12:48 < matches> Oh well, hopefully I can adapt whatever you do into RenderUsingASCII :P 12:49 < matches> I don't need GLX working to try and fix division but I'd really like to have GLX working 12:49 < matches> Sigh 13:12 < matches> I'm making progress, instead of reporting an invalid operation glxinfo segfaults now 13:13 < matches> So I have the wrong libraries or something... how to get the right ones... 13:32 <@sulix> Woo. I got it compiling again! 13:32 <@sulix> And the rendering is only half-wrong. 13:33 < matches> Nice 13:33 < matches> Manually deleting anything on my system with fglrx in it... 13:34 <@sulix> Someone really needs to write an "fglrx removal guide". 13:34 < matches> I'm not sure why reinstalling the radeon driver and mesa isn't actually giving me a libGL 13:34 < matches> At least 13:34 < matches> I suspect it is just leaving the existing broken one 13:36 <@sulix> So it turns out that *2 I don't understand is important. 14:01 < matches> Ok 14:01 < matches> I have glxgears 14:01 < matches> An epic achievement 14:01 < matches> I had to go back to fglrx but at least this time its the debian packaged version 14:02 < matches> The radeon driver seems to work better for stuff that isn't glx 14:03 < matches> Which is pretty cool but I kind of like glx actually working 14:11 < matches> Ok... time to fix division 14:11 < matches> Finally 14:11 < matches> No wait time for coffee 14:11 < matches> Then time to fix division 14:24 < matches> Did you test the div_digits function at all? 14:25 < matches> # We want to point to the end of the buffer (LSB) 14:25 < matches> Aren't I doing it the other way around... 14:25 < matches> I'll test it 14:28 <@sulix> With long division you do things in the opposite direction to addition. 14:29 <@sulix> I tested it with some simple things and it worked. 14:34 < matches> Hmm 16:35 < matches> Well the good news is that division is faster now 16:35 <@sulix> Cool! 16:36 < matches> The bad news is that I can't see anything 16:36 < matches> Even when GPU rendering 16:36 < matches> Also segfaults 16:36 <@sulix> I've just pushed some initial quadtree-enabling breakage. 16:36 < matches> I didn't work out how to apply the div_digits to a multi digit number either 16:36 <@sulix> Yeah, I thought about that, then went to bed. 16:36 < matches> I might convert the current algorithm which is all based on bit shifting 16:36 < matches> To assembly 16:37 < matches> But maybe not 16:37 < matches> Actually being able to see something render would be good even if it were slow 16:37 < matches> Then I can think about making it faster 16:38 <@sulix> The old one had all of the beziers connected for no readily apparent reason. 16:38 < matches> I have a tester called "Arbitrary Rationals" (arbrationals.cpp) which sounds like some kind of political party 16:39 < matches> A rather indecisive political party 16:39 <@sulix> That's amazing. 16:48 < matches> Ah, I might be having trouble with the sign of things, hm 16:49 < matches> Rational 15625/288230376151727369 (0.000000) is not close enough at representing 1.000000 (1.000000 vs 0.001000) 16:49 < matches> That doesn't look like a sign problem... 16:52 <@sulix> I admit, 15625/288230376151727369 is not really similar to 1. 16:54 < matches> So, somewhere along the way Arbint(1e6) became 15625 and Arbint(1e6) also became 288230376151727369 ? 16:54 < matches> Uninitialised things? 16:54 < matches> Constructing from int64_t seems fine 17:00 < matches> That amazing moment when it works perfectly and then you realise that's because you compiled with reals as doubles and not rationals 17:00 <@sulix> Ha: I've done that a few times. 17:19 < matches> Maybe I shouldn't have pulled your latest commit 17:19 < matches> Now I have two problems :( 17:22 < matches> Meeting tomorrow 17:22 < matches> "So how much progress have you made?" 17:22 < matches> "Segfaults are up 100% to a record high!" 17:26 < matches> Oh ok 17:26 < matches> I'm not sure if this is new 17:26 < matches> But if there is nothing in the document the GPU rendering doesn't like it 17:27 <@sulix> Hmmm... there might be some issues with that. 17:28 < matches> Ok 17:28 < matches> Rectangle renders 17:28 < matches> With arbitrary rationals 17:28 < matches> In the default view 17:29 <@sulix> Ooh! 17:31 < matches> I'm going to commit this even though it's totally broken 17:32 <@sulix> Things being broken hasn't stopped me from committing them. 17:35 < matches> I love this though 17:35 < matches> When you activate CPU rendering 17:36 < matches> You get like a billion errors from Rational::CheckAccuracy 17:36 < matches> And then the Bezier appears! 17:36 < matches> Magically! 17:36 < matches> I guess I shouldn't rule out a bug in CheckAccuracy :P 17:36 < matches> Although zooming will definitely cause a segfault 17:38 <@sulix> I tried running the really slow version under valgrind, but that turned out to be a bad idea. 17:39 < matches> I've pushed the slightly less really slow version 17:39 < matches> That is still really slow 17:39 < matches> I can't install kcachegrind 17:39 < matches> It is really annoying 17:40 < matches> There aren't any valgrind analysis things that don't require the entirity of KDE are there? 17:40 < matches> Or should I just learn how to read the raw output files 17:40 <@sulix> Cool: it works. 17:41 <@sulix> (I dunno, I just use KDE :P) 17:41 <@sulix> You can try "perf" or "oprofile". 17:41 < matches> Well I can't even install KDE :S 17:41 <@sulix> They're terminal-based. 17:41 <@sulix> Well, perf is, at least. There's a gtk+ oprofile gui. 17:41 <@sulix> They both measure the entire system by default though. 17:43 <@sulix> Rational::Simplify is ~54% of time (w/ GPU rendering) with the new build, according to callgrind. 17:50 < matches> I'm a little confused by some of the outputs of Rational::CheckAccuracy given that it does actually seem to render the bezier properly on the CPU 17:50 < matches> I think the segfault might be related to my (ab)use of things like memcpy on std::vector::data() 17:52 < matches> Also I think I've fixed my dependency hell 17:52 < matches> Well 17:53 < matches> Depending on how this turns out I will end up with the entirity of KDE hopefully including kcachegrind, or I will end up with no X again 17:53 < matches> And much swearing will ensue 17:54 <@sulix> Yeah, it segfaults immediately if you enable optimization level 2 or higher. 17:55 < matches> Hm 17:56 < matches> I'll probably get rid of std::vector then 17:57 <@sulix> The problem I'm seeing is in the vector::push_back() bit, so who knows what is going on. 17:58 < matches> Oh that's odd 17:58 <@sulix> Okay, don't run it in valgrind. 17:58 <@sulix> I'm getting about 200 "uninitialized values" a second in the nVidia driver. 17:58 < matches> But I just installed kcachegrind! 17:59 <@sulix> (Oh wait, that was with REAL=double) 17:59 < matches> Haha 18:00 < matches> Wait, vector::push_back causes problems even with REAL=double :S 18:00 <@sulix> Nah, the nVidia driver seems to. 18:01 <@sulix> I've now compiled again with REAL=5 and I'm getting a number of invalid reads off the end of the vector in GetBit() 18:02 < matches> Division 18:02 < matches> Oh 18:02 < matches> oooh 18:02 < matches> > -> >= 18:02 < matches> ... 18:03 <@sulix> Well, my first attempt to fix it just broke rendering. 18:04 <@sulix> Ah, yep, I see it. 18:05 < matches> I think I need to do less memcpy/memseting and more std::vector::operator= -_- 18:05 < matches> I mean, they implemented it for a reason 18:05 <@sulix> So, with that change it no longer segfaults! 18:05 <@sulix> (It corrupts memory and throws an exception instead) 18:05 < matches> Woah 18:06 < matches> I changed Arbint operator= to use std::vector operator= 18:06 < matches> And now I get a filled circle on top of my bezier... 18:07 < matches> Ok, I will rewrite Arbint to just rely solely on std::vector operations 18:08 < matches> That might slow it down but it's impossible to test that the maths works properly with all these memory errors 18:09 <@sulix> Should you be using m_sign more often? 18:09 <@sulix> It seems to be "forgotten" in a number of places... 18:10 <@sulix> Hmm... everything looks like it's working at the moment, actually. 18:10 < matches> What else did you change? 18:10 < matches> Try zooming 18:11 < matches> That will break it 18:11 <@sulix> Zooming seemed to work, actually. 18:11 < matches> Are you sure you compiled with REAL=5 18:11 < matches> The sign is a bit wierd 18:12 <@sulix> It works for a little bit, then the view bounds suddenly become huge. 18:12 < matches> Haha 18:12 <@sulix> For no reason, the y coordinate jumps to 10^8. 18:13 <@sulix> Also after you've zoomed, sometimes translating goes in the wrong direction or is otherwise broken. 18:15 < matches> That might be related to m_sign... 18:15 < matches> The joys of implementing your own number representation 18:16 <@sulix> Trying to "fix" the sign fixed zoom, but broke translation even more. 18:18 <@sulix> Also: best representation of 1 ever: 9223372036854775807/9223372036854775807 18:18 < matches> Hahaha 18:18 < matches> Oh 18:18 < matches> I think I commented out a Simplify() somewhere :P 18:18 < matches> No 18:18 < matches> I didn't 18:18 < matches> Hmm 18:19 < matches> Well I am going to push some minor changes 18:20 <@sulix> Also: T g = gcd(T(llabs(P)),T(llabs(Q))); 18:20 <@sulix> Is that "llabs" truncating everything? 18:20 < matches> ... 18:20 < matches> Probably 18:20 < matches> ! 19:05 <@sulix> Well, my attempt to write a templated abs() function that worked for Arbint may have worked, but it crashed X before I could find out. 19:05 <@sulix> I do not want to know how that is possible. 19:05 < matches> Heh, I was trying to do that before dinner 19:06 < matches> I just got segfaults 19:08 < matches> Oh 19:08 < matches> I see 19:08 <@sulix> I suspect the best thing for me to do is to just stash all of my changes and break some more quadtrees. 19:08 < matches> Yeah 19:08 <@sulix> But first I'll have to get X working again. 19:08 < matches> The problem with overriding llabs is that the constructor for Arbint calls llabs... 19:08 < matches> And Arbint has a constructor from int64_t... 19:09 < matches> So as soon as you implement llabs using Arbint it will call itself for eternity 19:09 <@sulix> I made a new function called "real_abs" (because "i_went_to_the_gym_now_look_at_my_abs" was too long) and just used that. 19:09 < matches> Bahaha 19:10 <@sulix> Then X started using 100% of my CPU and nothing responds to anything. 19:10 < matches> :S 19:10 <@sulix> The mouse cursor still moves, but everything else is a black screen. 19:11 <@sulix> Excellent, "sudo pkill -9 Xorg" has made everything work again. 19:12 <@sulix> (And even fixed an unrelated problem, which is good but worrying) 19:17 <@sulix> Note to self: if something crashes X when you run it once, don't run it again after fixing X. 19:18 < matches> Haha 19:18 <@sulix> Now to try it for a third time. 19:18 < matches> I've got an abs working 19:18 <@sulix> Ah, excellent. 19:19 <@sulix> Does it make things better? Worse? The same but slower? 19:19 <@sulix> Crash X? 19:20 < matches> It doesn't crash X but I think I have an infinite loop in gcd now 19:21 < matches> I should probably work out why X/X for really big X is not simplifying to 1/1 19:43 < matches> So it turns out it's a pretty good idea to have a tester that actually tests lots of different numbers with every single operation 19:43 < matches> As opposed to 19:43 < matches> "1/2 == 0.5" yep looks good she'll be right 19:43 < matches> One could say 19:43 < matches> There are *signs* of serious problems 19:44 * matches puts on sunglasses 19:44 < matches> No wait I got the order wrong 19:44 < matches> Oh well I wasn't cool enough to watch that show anyway 20:18 < matches> So now I have a tester that actually tests things 20:18 < matches> I just need to blindly fumble around with m_sign until all the tests are passed! 20:18 < matches> Right?! 20:26 < matches> Heh, it's amazing how many errors fixing the sign in Division prevents 20:27 < matches> Well amazing until you realise that every single Rational calls a division at least once 20:44 <@sulix> Hmmm... there seem to be a lot of cases where we get things becoming 1 (randomnumber/randomnumber) instead of what they should be, according to CheckAccuracy. 20:46 < matches> Yeah 20:46 < matches> It should work nicer nowish 20:46 < matches> At least, the tester works most of the time... 20:46 < matches> It still randomly fails sometimes 20:46 <@sulix> Yeah, it's working much better. 20:46 < matches> Now 12% of the time is in std::vector::size() 20:46 <@sulix> All of the things I've seen have been to do with subtraction in ScaleAroundPoint() 20:47 < matches> Ah 20:47 < matches> Wait I haven't pushed the 12% in std::vector::size yet 20:47 < matches> tl;dr I was allocating one extra digit every single addition operation and then deleting it if it wasn't used 20:48 < matches> Because I am just that good :P 20:48 < matches> I suspect the Arbint is going to break when it actually does need to resize itself 20:49 < matches> But for now I will settle for "At least as good as an int64_t" 20:49 < matches> * But slower 20:49 <@sulix> I'm curious as to why digit_t is int64_t and not uint64_t. 20:49 < matches> Oh it is uint64_t now 20:49 < matches> It was int64_t mainly because geany doesn't syntax highlight uint64_t 20:50 <@sulix> Ah. 20:50 < matches> Then I realised being int64_t instead of uint64_t broke the shift operators 20:50 < matches> Because they try to preserve the sign 20:50 <@sulix> Shift on signed ints is undefined behaviour, IIRC. 20:51 < matches> Yeah I was considering writing the shift in assembly but its easier to handle the underflow/overflow into the next digit in C 20:52 < matches> Zooming is still incredibly slow 20:54 < matches> In fact it is infinitely slow 20:54 <@sulix> I once waited about 10 minutes and did get another frame. 20:54 < matches> In fact the Arbint appears to want to grow an infinite number of 0L digits 20:55 <@sulix> Ah ha! I have realised why CheckAccuracy is only throwing errors on "-". 20:55 <@sulix> The CheckAccuracy calls for everything else have been commented out, 20:55 < matches> They should all be commented out so I can use tests/realops.test instead 20:57 < matches> 23 / 12000 operations failed... doesn't seem too bad... 20:58 <@sulix> Keep in mind that == isn't precise as it casts to doubles. 20:58 < matches> You get more like 40 out of Rational 20:58 < matches> Yeah they are "equal" if it is within 1e-1 :S 20:58 < matches> I'm searching for the more totally catastrophic failures like the wrong sign first :P 21:20 < matches> Ok tomorrow I might just try using boost arbitrary integers or something 21:28 <@sulix> All of the failures I'm getting are with "/=" 21:28 <@sulix> Except one, which was only just outside the error bounds, so probably the doubles' fault. 21:30 < matches> I was restricting the test values somewhat though 21:30 < matches> (With rand()%100 + 1) 21:33 <@sulix> You do know that the Rational -> double conversion is totally broken if either P or Q have > 1 digit. 21:33 < matches> Yeah I noticed that 21:37 <@sulix> Oh man, re-enabling the operator double on Arbint totally breaks things. 21:40 < matches> Yeah don't touch it 21:40 < matches> Basically touching anything will totally break something else 21:40 < matches> :S 21:40 < matches> I should probably sleep some more before attempting to fix things 21:40 <@sulix> The other bug I just found is that Arbint didn't have the unary "-" operator, so writing "-P" would silently cast to int64_t. 21:41 < matches> Ah ok 21:41 < matches> I thought unary - was equivelant to "0 - x" but I suppose that doesn't make sense 21:41 <@sulix> Nah, it has to be written explicitly. 21:44 <@sulix> Okay, I think I've got realops.test down to 0 errors with Arbint. 21:45 < matches> Well you're doing better than me 21:46 <@sulix> I'm running it with a huge number of tests now. 21:47 <@sulix> 85.95% of my entire computer's processing time is in IPDF::Rational::operator/= 21:48 < matches> Can you push what you have? 21:48 <@sulix> Yeah, I will in a second. 21:48 <@sulix> It's basically a lot of hacks. 21:49 <@sulix> CPU rendering is broken, though. 21:49 < matches> There were cases where it would grow an infinite number of digits; did you fix those? 21:49 <@sulix> Probably not: it still gets very, very slow zooming. 21:51 < matches> Yeah there's something wrongish it shouldn't need extra digits so fast 21:51 <@sulix> Pushed now. 21:52 <@sulix> Now to look at the diff and see what I actually changed. 21:53 < matches> Oh 21:54 < matches> Simplify call in Rational operator= is good 21:56 < matches> I think I fixed some more bugs but I also introduced an infinite loop so... 21:57 < matches> How is the quad tree bit going :P 21:57 <@sulix> Yeah, about that... 21:58 < matches> Remember Arbints don't have to work for quad trees to work :P 21:58 < matches> Or do they 21:58 <@sulix> In theory, no. 21:58 <@sulix> In practise, it probably depends on how one defines "success". 21:59 < matches> I think we need to design a test pattern where you actually want to zoom forever 21:59 <@sulix> Highly theoretically, I'm pretty certain the QuadTree basically ends up isomorphic to the Arbint. 21:59 < matches> Seems legit 21:59 < matches> Can you prove it? 21:59 < matches> That would be a useful result 21:59 <@sulix> Yes* 22:00 <@sulix> *hopefully 22:00 < matches> I'm afraid most of my "theory" is based solely on intuition at this point :S 22:00 < matches> Well the division algorithm came from wikipedia but division isn't as intuitive as the other operations 22:01 < matches> Actually if I can fix all these other stupid bugs I'll try my binary searchish division idea 22:01 <@sulix> Yeah, I spent a while racking my brain for long division, and then only managing to work it out for dividing by a single digit. 22:02 <@sulix> That's really, really easy in asm, as well, which is nice, but not quite as useful as I'd hoped. 22:02 < matches> It's pretty useful; we can still have a "if div.m_digits.size() use the assembly function" 22:02 < matches> * size() == 1 that is 22:02 <@sulix> Wikipedia mentioned doing newton-raphson for division, which is a terrifying thought. 22:02 < matches> Haha 22:03 < matches> So I've got Arbint::Shrink() calls pretty much after every operation now for no apparent reason 22:04 <@sulix> Does it help? 22:05 < matches> On the 551st test Shrink has been called 4 times in a row and then something after that causes an infinite loop 22:05 < matches> I can't work out what it is 22:05 < matches> I have a GrowDigit that spams Debug messages now 22:05 < matches> So its not that 22:05 < matches> It's silent 22:05 < matches> Let's see what callgrind has to say 22:06 < matches> A few minutes should be enough for it to be obvious right 22:07 < matches> I think the division loop runs forever 22:07 < matches> Bugger 22:08 < matches> Wait that doesn't make sense there's only 1 digit 22:08 < matches> Blargh 22:17 <@sulix> So using the asm version when possible makes realops.test 20x faster, but there were a couple of failed tests. 22:18 <@sulix> I'm not sure if they're new or not, because I was able to run many more tests. 22:20 <@sulix> Also, I think I've found your infinite loop. 22:23 <@sulix> Okay, maybe I've just obfuscated the code some more. 22:24 < matches> Infinite loop is due to subtraction bug 22:24 < matches> I'm pretty sure 22:24 <@sulix> Yeah, pushing a "fix" 22:26 <@sulix> Pushed, but think I might have found a bug in the fix. 22:26 < matches> Ok 22:27 < matches> (0,0) - +(16292953875657448384,1) = -(16292953875657448384,2) seems wrong 22:28 <@sulix> Pish! Nothing could be more beautiful. 22:28 < matches> It's pretty hard to debug with such huge numbers :P 22:31 <@sulix> Try this... 22:31 * sulix pushes. 22:32 < matches> What does that do... 22:33 < matches> oh 22:33 < matches> You negate the entire thing and add one 22:33 < matches> Seems legit 22:33 <@sulix> So "two's complement" negatives mean that -A == flip all bits of A and add 1. 22:33 < matches> Yeah 22:34 <@sulix> There seems to be a bug in the asm div_digits though. 22:35 < matches> I'm taking that out until I know the main algorithm works :P 22:35 < matches> Silly I spent so much time wondering why division was broken without checking subtraction 22:36 < matches> After I spent all that time thinking I was so clever for doing division using bit shifts and subtractions 22:37 <@sulix> It still takes forever. 22:37 <@sulix> (Zooming in, that is) 22:37 < matches> Nah there's still a bug 22:37 < matches> You're running with an older version of realops test 22:37 < matches> Hang on 22:37 < matches> I will push things 22:38 < matches> Trying to avoid a merge... 22:38 <@sulix> And I will get a drink. 22:44 < matches> So if you run enough tests you eventually get a bunch of SubBasic spam 22:45 < matches> Which is actually occuring due to "<" operators 22:45 <@sulix> Yeah: I'm going to add a bunch of hacks to "<" at some point. 22:45 < matches> Which are in the Division loop ( >= is implemented in terms of <) 22:45 < matches> Don't add the hacks until subtraction works! 22:46 < matches> I don't want to optimise it yet 22:46 < matches> Otherwise all the optimisations hide the bugs 22:47 < matches> Time for a tester that just does subtractions I think 22:48 <@sulix> It might be worth adding a bunch of SDL_assert_paranoid()'s everywhere that check that (a - b)+b == a and similar on every - call. 22:49 < matches> Most of the tested numbers can be represented in a single digit which is causing problems 22:50 < matches> With finding the bugs in the multi-digit algorithm 22:52 < matches> For small enough multi digit Arbints testing against doubles might work? 22:52 <@sulix> Maybe. 22:53 <@sulix> You'd lose enough precision that it's not worth it for anything > 2 digits, I'd say. 22:53 < matches> Yeah, 2 digits should be enough to make sure the algorithms actually work though 22:54 < matches> 2 digits in one operand and 1 in the other (which will resize itself to have a leading zero if necessary) 22:55 < matches> At some point I am going to have to use a library for Arbints and compare ours to it 22:55 < matches> But I kind of want ours to work properly before bringing in an external one 22:56 < matches> When I try floats I might just bring in the external library :P 22:56 <@sulix> Two questions: 22:57 <@sulix> 1. What is "borrow" supposed to be? Is it the "carry" or the "result has changed sign" or something else? 22:57 <@sulix> 2. What do you think of replacing Sub() with Add() + Negate()? 22:59 < matches> borrow's like carry (I'm using subtract with borrow in asm) it should get subtracted from the next digit, and if at the end it is still set then it means your result is less than zero 22:59 < matches> and 2 sounds like an excellent idea 23:00 <@sulix> Okay. 23:00 <@sulix> 'cause there's a separate "carry" flag and "sign" flag, so I wasn't sure. 23:01 < matches> subtract actually working would be slightly faster than add and then negate I think 23:01 <@sulix> I'm not 100% sure if all the code is using m_sign as the sign or if some of it is trying to use 2's complement, which isn't really possible with arbints. 23:03 < matches> When I was testing the subtraction code I was using int64_t instead of uint64_t and it seemed to work :S 23:04 < matches> I should check whether sbb does unsigned or signed subtraction 23:04 <@sulix> Both, I think. 23:04 <@sulix> 2's complement makes them the same, which is why it's so nice. 23:04 <@sulix> But it requires a fixed number of bits to work. 23:09 < matches> Whoops now the bit shift tester runs forever as well 23:13 < matches> Oh no it doesn't 23:13 < matches> It just exceeds the limit on GrowDigits 23:14 < matches> Phew 23:14 < matches> Bit shifting works at least 23:14 < matches> Or at least it is consistently broken 23:14 < matches> (a >> X) << X == a 23:14 < matches> But == could be broken 23:14 < matches> NOTHING IS SAFE 23:14 < matches> When you are writing your own number represntation :( 23:15 <@sulix> Idea: 2's complement subtraction will make -ve numbers have an "infinite" number of 1s at the front, so would that be infinite looping, trying to continually add digits with 1s. 23:15 < matches> Operator overloading is amazingly powerful and yet it seems like the best way to make seemingly sane code do batshit insane things 23:15 <@sulix> I think the answer is "no: we're always trapping it and converting it" but am not sure. 23:16 < matches> Our subtraction doesn't take forever 23:16 < matches> The issue is when the result would be less than zero 23:16 < matches> Hang on let me make another tester 23:17 < matches> Well, I'll put it in the arbint tester instead of the real tester 23:18 < matches> Since it's pretty clear the bugs are in arbint not rational itself 23:18 < matches> Although there might be bugs in rational as well 23:18 < matches> But we'll squish those when we get to them 23:18 < matches> Also quad trees are they a thing yet? 23:20 <@sulix> "The quadtrees aren't in the code, they were in your heart all along." 23:21 < matches> Haha 23:21 < matches> Tell that to Tim :P 23:21 < matches> Ok (45,10) - (128,0) = -(83,18446744073709551605) 23:21 < matches> But I'm pretty sure it should be -(83,9) 23:21 < matches> + even 23:22 < matches> (The least significant digit is first) 23:23 < matches> Actually the plot thickens 23:23 < matches> +45,10 - +128,0 = +18446744073709551533,9 23:23 < matches> +45,10 - +128 = -83,18446744073709551605 23:23 <@sulix> What is 0 + -1? 23:24 < matches> +0 + -1 = -1 23:24 <@sulix> I am pleased to hear that. 23:25 < matches> +0 - +1 = -1 23:25 <@sulix> -1 + 2? 23:25 < matches> Now you're getting tricky... 23:25 <@sulix> (As a maths major, I should know this) 23:25 < matches> -1 - +2 = +1 23:25 < matches> They're all single digit though 23:26 <@sulix> Do you mean -1 + +2 = +1? 23:26 <@sulix> Otherwise I'm slightly concerned. 23:26 < matches> Uh yeah 23:26 < matches> Sorry I have to change both the Arbint c(a + b) and the Debug 23:26 < matches> Before copy pasting 23:27 < matches> So I guess I should calculate if 45 + 10*2^64 - 128 == 18446744073709551533 + 9*2^64 23:31 < matches> Expletive grenade 23:31 < matches> I started Mathematica 23:31 < matches> fglrx segfaulted 23:31 < matches> startx 23:32 < matches> -bash: /usr/bin/startx: No such file or directory 23:32 < matches> Also now I am getting zenity int3 error messages all over the bottom line of my terminal 23:33 < matches> Whyyy 23:33 <@sulix> That's terrible. 23:33 < matches> Why does this computer persecute me so 23:34 < matches> I gave it a good life 23:34 <@sulix> You should ask frames how he runs mathematica on the command line. 23:34 < matches> I fed it lots of AC power 23:34 < matches> I replaced that keyboard that I broke 23:34 < matches> I only spilled coffee on it once 23:34 < matches> I *tried* to use the drivers that weren't fglrx 23:35 < matches> I give up, see you tomorrow. Try not to totally rewrite all the Arbint code :P 23:35 < matches> I think the subtraction might actually work except for the resizing bit 23:35 <@sulix> Nah, I'm calling it a night here too. 23:36 <@sulix> I tried replacing the carry bit with the sign bit and all went to hell there, so I'm inclined to agree with you. 23:37 < matches> Well using my calculator I get something with a 184 ish at the start and too many digits to display 23:37 < matches> Hence the mathematica disaster 23:40 < matches> Oh well, I got startx back by installing "xinit" so that's something 23:41 < matches> I guess apt decided to remove it as part of apt-get autoremove in its infinite wisdom 23:41 <@sulix> I have decided to never call apt-get autoremove. 23:42 <@sulix> If at any point there are too many old packages for me to get things done, I'll just reinstall the OS entirely. --- Day changed Mon Jul 07 2014 08:40 < matches> I try to avoid it, but sometimes apt won't let me do anything because it would break some dependency 08:40 < matches> Although usually even after I run autoremove it complains 08:41 < matches> Had to use aptitude to fix my "You can'd have kde-runtime!" issues 08:45 < matches> Anyway wolfram alpha says that example +45,10 - +128 == +18446744073709551533,9 08:45 < matches> is correct 08:45 < matches> Checking the algorithm using 8 bits it should work too 08:46 < matches> So it works as long as you supply the leading zeros... 08:46 < matches> (On that particular case...) 08:48 < matches> I hope it's not interpreting Arbint(128L) as Arbint(128u, ...) 08:48 < matches> Nope sanity seems to prevail there 08:50 < matches> Ah 08:50 < matches> Ok 08:50 < matches> First bug of the day: The subtracted argument needs to be resized 08:50 < matches> As I am doing (45,10) - (128) 08:59 < matches> :O 08:59 < matches> I passed the realops test 09:00 < matches> And it's also a lot faster now! 09:00 < matches> Probably because the subtraction bug meant it was spending a long time in division to get the wrong result 09:01 < matches> Yeah it should have been obvious division can't have been that slow for numbers starting at 64 bits since it does at most as many iterations as the number of bits 09:01 < matches> Oh well 09:02 < matches> Should probably not celebrate just yet, now the bezier looks really wierd again 09:04 < matches> Ok 09:04 < matches> Actually compiling with Real == Rational might be a better test 09:04 < matches> But it still passes 09:05 < matches> In particular it passes with Arbints where int64_t fails horribly 09:05 < matches> So something is right 09:05 < matches> Just not all of it... 09:08 < matches> The GPU rendering seems to workish 09:09 < matches> We really quickly end up with Arbints of size 30 digits or so :S 09:09 < matches> Which is big enough to give an overflow in doubles I think 09:10 < matches> Rational::ToDouble can probably be written as double(integer division) + Rational(remainder, quotient).ToDouble() 09:10 < matches> (With some things to stop it recursing infinitely) 09:20 < matches> Or even double(integer division) + double(remainder)/double(quotient) 09:20 < matches> I don't think any recursion is needed 09:22 < matches> Oh, there's a "pow" call that is probably broken 09:24 <@sulix> Yeah, I feel the growing quickly is just a fact of life. 09:25 <@sulix> Perhaps changing the zooming to avoid coprimes or something. 09:27 <@sulix> I'm pretty certain that about 3 seconds of zooming is enough to make us need precision and range to match measuring the size of the visible universe in Planck lengths, too. 09:28 <@sulix> "New biggest Arbint of size 173" 09:28 <@sulix> and counting... 09:34 < matches> haha 09:34 < matches> There are more issues I spotted with add and subtract 09:34 < matches> Basically you have to add the leading zeros - all of them 09:35 < matches> My patch only simulates adding one leading zero 09:35 < matches> Actually maybe I don't need to add them all, just enough until the borrow becomes zero 09:36 < matches> But whatever 09:36 < matches> If you're left with a borrow you can't assume that subtracting it from the next digit won't cause a borrow as well 09:37 < matches> Realops is not a good enough tester 09:42 <@sulix> Surely if there's borrow bit, subracting it from zero will always give another...? 09:42 < matches> You only need as many as there are digits in your number 09:42 < matches> At most 09:42 < matches> If you still have a borrow at the end 09:42 < matches> That means the result is negative 09:43 <@sulix> Yeah, that's what I thought: you need to cap the number of digits you add. 09:44 < matches> The problem was the algorithm before didn't finish all the borrows 09:44 < matches> eg: 100 - 2 would have become "-8" 09:44 < matches> Because 2 only has one digit 09:44 <@sulix> My powers of mathematics tell me that that is not quite correct. 09:45 < matches> What, that our algorithm was wrong? 09:45 <@sulix> No, that 100-2 is not -8 09:45 < matches> Yes 09:45 < matches> Yes that's the problem :P 09:46 < matches> So basically the two numbers need to be the same size but since we have a constant argument I'm sticking in a "borrow_digits" vector if there is a borrow 09:46 < matches> Addition also needs it for carry 09:46 < matches> Damn 09:47 < matches> I'd hoped that might fix the beziers not looking like beziers on the CPU bug 09:50 <@sulix> I've pushed code to clear the carry/borrow flag before adding/subtracting. 09:50 <@sulix> I don't think any bug is triggered, but there was the potential for off-by-one errors. 09:52 < matches> Argh no 09:52 < matches> Merge 09:53 < matches> Yeah I'm pushing a fix for bugs that I don't think we've seen (yet) 09:54 <@sulix> Out of curiosity, I tried removing the Simplify() calls from Rational. 09:54 <@sulix> Relatedly, I've coined the term "NaN soup" 09:54 < matches> Oh, clearing the carry/borrow flag might actually fix a bug with the code I just committed 09:54 < matches> No wait it won't 09:55 < matches> Eh it's still kind of dangerous to assume it isn't set to start with 09:55 <@sulix> I think the flag was probably already cleared by the code the compiler generated, but that might not be the case if it's optimized. 09:55 < matches> One of my early attempts had inline adc instructions in a for loop 09:56 < matches> Which failed miserably because the for loop was clearing the carry flag :P 09:57 <@sulix> For some reason "*=" segfaults if optimization is enabled, but I don't know why. 09:57 < matches> Yuk 09:58 <@sulix> Somehow we end up with "mul" as a null reference. 09:58 < matches> Rataional::*= or Arbint? 09:58 <@sulix> Arbint 09:58 <@sulix> (So, also rational) 09:58 <@sulix> Valgrind isn't picking anything up. 09:58 < matches> null references are the worst 09:59 < matches> Since I'm pretty sure the point of a reference is that it is never null... 09:59 < matches> I'm sure this doesn' 09:59 < matches> t stop people from deliberately creating null references 09:59 < matches> And also checking that they are not null 10:02 <@sulix> Tried compiling with clang. Nope. 10:02 <@sulix> Apparently not even #include compiles with clang. 10:02 < matches> It might be worth implementing a non assembly version of those functions 10:03 <@sulix> Yeah, that's always a good idea. 10:03 <@sulix> The assembly ones are more fun, though. 10:16 < matches> Hmm I should probably head towards the meeting 16:23 < matches> I have pushed a Gmpint wrapper thing 16:23 < matches> It mimics Arbint as closely as possible. 16:24 < matches> Well by that I mean I just wrapped all the calls to mpz_add() etc in operators 16:24 < matches> It doesn't have all of Arbint's more esoteric functions 16:24 < matches> If we need bit shifts I think I can add them 16:27 < matches> So, writing stuff... 16:28 < matches> Running arbint_vs_gmpint.test in valgrind takes a fair while 16:28 < matches> We will have the definitive answer of just how terrible our multiplication is compared to the Professional (TM) implementation 16:29 < matches> I do have some good news, I think our string conversion might be better 16:29 < matches> Well if you ignore the division 16:31 < matches> *= is about 11 times slower 16:32 < matches> Most of that is in std::vector::resize() 16:32 < matches> But even just mul_digits is greater than the entire Gmpint::operator*= 16:32 < matches> The plot thickens as I try division 16:32 < matches> Which is a good opportunity to get food because it will probably take an hour 16:34 < matches> Note: Don't disable Debug messages if you want time to get food :( 16:35 < matches> And division is just under 100* slower 16:36 < matches> No 16:36 < matches> 1000* 16:37 < matches> So... if we change Rational to Rational... 16:41 < matches> We still get {nan,nan,nan,nan} eventually but it is generally less shoddy 16:50 <@sulix> Cool: looking at this now. 16:50 <@sulix> I'm digging through the gmp source code as well. 16:51 <@sulix> They have a similar "divide by single int64_t" optimization. 16:51 <@sulix> Also their code is 90% preprocessor macros. 16:51 < matches> Welp 16:51 < matches> At least we have a readable Arbint 16:52 < matches> I don't know what use a readable but slow implementation is 16:52 <@sulix> Ah: I see what they're doing: this is quite clever, particularly from a pure maths point of view. 16:52 <@sulix> They've got a natural number implementation, and have then built their integer representation around that. 16:53 <@sulix> The natural numbler implementation is just a huge set of directories with different assembly implementation. 16:53 <@sulix> So there's an "x86_64" directory, and in that there's a bunch of assembly + a bunch of directories with optimized versions for different individual processor models. 16:55 <@sulix> Also their assembly has lots of ASCII art comments. 16:56 <@sulix> and macros. 17:07 < matches> Yeah "just use GMP" is probably the answer 17:08 < matches> Their Makefiles are pretty intimidating 17:22 < matches> I like that they seem to store the sign as part of the size 17:22 < matches> If something has a negative size it is negative and has |size| digits 17:34 < matches> I guess I will try and write some sort of report about how we implemented Arbitrary Integers but they are terrible compared to existing implementations :P --- Day changed Thu Jul 24 2014 14:44 < matches> So I was going to work on the project but existential dread 14:45 < matches> About whether my major exists 14:45 < matches> Do I exist? 14:49 <@sulix> Are you thinking? Because cogito ergo sum. 14:50 < matches> I'm not sure I was thinking when I picked this major... 14:50 <@sulix> I did some project code yesterday and then a bug I thought I'd fixed reappeared so I got distracted failing to fix that. 14:50 < matches> Haha 14:53 < matches> Should I upset everyone and recommend freshers for wheel again... 14:54 <@sulix> I'm all for it, but I think the consensus was that we need to make them actually do wheel-y projects first. 14:55 < matches> That seems kind of hypocritical though 14:55 < matches> Because nearly none of active wheel has actually done wheel-y projects 14:55 < matches> Certainly not before getting on wheel 14:56 <@sulix> My current random guess is that the problem is that people used to fix the desktops and stuff, and now everyone has their own laptops to break. 14:56 < matches> But I'll be quiet or people might decide I need to be removed due to lack of doing useful things 14:56 < matches> Yeah 14:56 < matches> That too 14:57 <@sulix> I'll definitely bring it up at the meeting. 15:02 <@sulix> So which CoderDojo forms do I need to fill out? 15:02 < matches> Ooh! 15:02 < matches> http://coderdojowa.org.au/volunteer 15:02 < matches> This one 15:03 < matches> But now you've said that I'm already adding you to the mailing list... 15:04 < matches> There's a thing on Saturday in 2.01 in CS at 12:00pm 15:04 < matches> I hope people actually show up because we are pretty short on presenters 15:04 <@sulix> Yeah, I've got a programming competition then. I'm trying to work out how much of the schedule for the competitions exists. 15:06 <@sulix> Okay, apparently there are programming competitions every saturday in August, which will be fun. 15:07 <@sulix> Although half of them are "details TBD," which sounds ominous. 15:07 <@sulix> Also there is a round 2 and a round 4 but no round 3. 15:11 <@sulix> Okay: it looks like the only weeks I don't have programming competitions on are the last 3 on the form. 15:13 <@sulix> Also I suspect they're running out of names for the programming competitions, because this Saturday's is called the "South Pacific Winter Programming Carnival". 15:21 < matches> Haha 15:27 <@sulix> Form submitted. Sorry for the snarkiness. 15:40 < matches> Brilliant 15:40 < matches> You can do a C or C++ workshop or something :P 15:40 < matches> Or just talk about Commander Keen that'll work 15:40 < matches> Or "Why Javascript is awful and you should forget all the lessons" 15:42 <@sulix> "Intro to DOS programming." :P 18:38 < matches> I did a sort of half hearted attempt at writing more about Arbints 18:39 < matches> Maybe I'll try put fonts in 18:39 < matches> That seems vaguely like not what I am supposed to be doing right now :P 18:43 < matches> There's that virtual FPU sitting there doing nothing 18:43 < matches> That I promised to do things with in my lit review 18:43 < matches> That Tim is marking 18:43 < matches> When I haven't actually done anything with it and he knows it... 18:44 < matches> I can't help but feel like we need a more impressive thing to zoom in on 18:44 < matches> Or even a way to draw things once we have zoomed in 18:46 < matches> Does "We implemented Arbitrary Precision Integers but GMP did it better" count as research? 19:13 < matches> Do we have a memory leak? 19:13 < matches> I've been running it for a while and things are slowing down 19:25 <@sulix> matches: With GMP or just doubles? 19:27 <@sulix> My quick check has us not leaking memory with doubles. 19:27 <@sulix> Well, X leaks memory and the nVidia driver leaks memory, but we're fine. 19:35 < matches> I was actually running with singles :S 19:35 < matches> See push to documents repo 19:35 < matches> There is a pdf 19:35 < matches> I did a thing 19:38 < matches> I'm basing the assumption that x86-64 is IEEE compliant on the fact that it passed the "paranoia" program 19:39 <@sulix> Yeah, x86_64 is IEEE compliant. 19:39 <@sulix> x86_32 is "mostly" IEEE compliant if I recall. 19:41 < matches> Well a picture tells a thousand words 19:41 < matches> So I think I wrote 8000 words today 19:41 < matches> Progress! 19:43 <@sulix> http://cgit.freedesktop.org/mesa/mesa/tree/src/mesa/drivers/dri/i965/brw_defines.h?id=9d6166880da83887e3246fb4498c3a07d979cc3b#n162 19:43 <@sulix> I'll see if I can find where they actually set it to non IEEE. 19:43 < matches> Oh I was going to say fglrx did different things to nVidea but as I don't have nVidea that's difficult to do 19:45 <@sulix> Although there's this: http://lists.freedesktop.org/archives/mesa-dev/2013-July/041555.html 19:45 <@sulix> Yeah, nVidia, Intel and fglrx all seem to do different things. 19:45 <@sulix> fglrx does the strangest things. 19:45 <@sulix> nVidia does the most consistant things. 19:45 <@sulix> Intel sits nicely in the middle. 19:46 < matches> If we can get four screenshots of the different things at the same view bounds that might be useful 19:47 < matches> Also working out more about what the jagged edges implies about the precision/rounding might be helpful 19:47 < matches> All I've got is "This is clearly not a circle" 19:48 < matches> So it's still doing that with the quad trees enabled, so I assume the quad trees aren't amazingly quadifying everything yet :P 19:48 <@sulix> The quadtrees are basically doing nothing but occasionally causing bugs. 19:48 <@sulix> http://davidgow.net/stuff/ipdf-nvidia.png 19:48 < matches> That is progress at least 19:49 < matches> Thanks 19:49 < matches> I will update the others to be the same view bounds 19:49 < matches> I *think* we have code to set the view bounds at start? 19:51 <@sulix> http://davidgow.net/stuff/ipdf-intel.png 19:51 < matches> Haha 19:51 < matches> Well it's really obvious that that's different 19:52 < matches> Can you rerun it with -b 0.0869386 0.634194 2.63295e-07 2.63295e-07 19:52 < matches> Obsessive compulsive... 19:52 < matches> Must all be same view bounds... 19:53 < matches> I'd run it on my other laptop with intel integrated graphics except the keyboard still doesn't work 19:55 < matches> Actually don't bother 19:55 <@sulix> http://davidgow.net/stuff/ipdf-nvidia1.png 19:57 <@sulix> http://davidgow.net/stuff/ipdf-intel1.png 19:59 < matches> oah wierd stuff is happening with the quad tree 19:59 < matches> There is a big circle and a little circle 19:59 < matches> Is that supposed to be here... 20:00 < matches> The distance between them is not constant :S 20:09 <@sulix> Yeah, that doesn't happen on intel and is the bug I've been hitting my head against. 20:09 <@sulix> Pretty certain I'm trying to render one more object than there actually is somewhere, maybe corruping memory in the process. 20:32 < matches> Ok so it turns out the CPU is actually about as terrible as the GPU at those view bounds when you replace the "double" with "float" in the Circle Renderer :S 20:32 <@sulix> That's what I expected. 20:32 <@sulix> It looks like the nVidia one, right? 20:32 < matches> But it does slightly different wrong things! 20:34 < matches> It looks similar-ish 20:35 < matches> It is blocky as opposed to zig zaggy 20:39 < matches> As in it doesn't look as whack as intel 20:43 <@sulix> Hmm... I'm not sure what I'm doing wrong, but I can't see any artefacts at all with CPU rendering w/ those bounds. 20:55 < matches> They are hard coded as doubles 20:55 < matches> Not floats 20:55 < matches> Or reals rather 20:56 <@sulix> Ah. 20:56 <@sulix> This explains much. 21:08 < matches> I have pushed a thing 21:09 < matches> It almost sounds like a real paper 21:09 < matches> Until you realise all it is is "we drew some circles and they look different" 21:09 < matches> Also your screenshots had some kind of crazy blue glowy border 21:10 <@sulix> Yeah, that's the KDE window shadow. 21:10 < matches> Fancy 21:10 <@sulix> It used to make the nVidia driver corrupt screenshots, but it seems to work now. 21:11 < matches> I'm pretty pleased with that 4 way comparison figure... 21:12 < matches> "One of these things is not like the others..." 21:12 < matches> *cough* intel 21:12 <@sulix> The conclusion is brilliant. 21:15 < matches> If we assume the nVidia and x86-64 figures are what things are supposed to look like 21:15 < matches> fglrx tries really hard 21:15 < matches> But doesn't quite make it 21:16 < matches> (I'm pretty sure that's just a particularly good view for it) 21:16 < matches> (If you move it around it goes insane) 21:16 < matches> I can respect the intel shader 21:16 < matches> It isn't afraid to blatantly disregard the rules 21:17 < matches> intel driver rather 21:17 < matches> Not sure why I put "shader" there 21:17 < matches> This has not been as productive as I hoped 21:18 < matches> Still 21:18 < matches> We finally have something written that Tim can pass judgement on 21:18 < matches> He's still in the country right? 21:19 < matches> He might want to finish passing judgement on my literature review first :S 21:21 <@sulix> I think he's still in the country, but don't hold me to that. 21:22 < matches> Ok, so if you translate around with the CPU things don't go insane, but they do on the GPU. That might be caused by something else though. 21:23 < matches> I'll be at University tomorrow 21:24 <@sulix> I might head in, too, then. 21:25 <@sulix> Do things still "go insane" on the GPU with CPU-side coordinate transforms. 21:26 < matches> Yeah 21:26 < matches> It looks like there is a tear 21:27 < matches> So you get this rectangle pattern 21:27 < matches> If you move it around on the CPU it maintains its shape 21:28 <@sulix> I think that fglrx (or maybe just the AMD hardware) calculates the coordinates per-triangle rather than per-vertex or something. 21:28 < matches> Under fglrx the bottom part of it sort of maintains its shape but there is a big diagonal line and the stuff above that changes 21:28 <@sulix> That's pretty weird. 21:29 < matches> Also the bottom part doesn't have concave bits but the top occasionally gets one 21:29 < matches> concave/overhanging whatever 21:29 <@sulix> The whole thing maintains its shape on nvidia (and even intel) 21:29 < matches> Well, the bottom half (and also the CPU/nVidia entire thing) looks kind of like a stair case 21:29 < matches> The top bit gets all these sticky out bits and overhangs 21:30 < matches> Which brings us to our next paper 21:30 < matches> The geology of fglrx 21:30 <@sulix> Intel also does the "staircase" on the other side of the circle. 21:30 < matches> On the other side... 21:30 < matches> Hmm the plot thickens 21:31 < matches> Oh well I need to sleep 21:31 < matches> Why do I feel like I have actually lost sleep over the holidays... 21:32 < matches> I am not ready for semester to start :( 21:32 <@sulix> I know exactly what you mean. 21:33 < matches> I seem to have been roped into unpaid work with physics 21:34 <@sulix> Oh dear. More lab demonstrating or something more interesting? 21:34 < matches> Hopefully if I visit ECM they won't make me do GENG5505 yet 21:34 < matches> Fixing my honours experiment I think... 21:35 <@sulix> Another pipe corroded through? 21:35 < matches> Haha 21:35 < matches> They were wondering where all the electronics went 21:35 < matches> (I have most of it) 21:35 < matches> (Also it's no longer functional) 21:36 < matches> (I may have taken some of it apart...) 21:36 < matches> (Although really the sensible option would have been to burn it with fire) 21:37 < matches> Goodnight anyway 21:37 <@sulix> I'm required to "correct" anything they want to change with this project after submitting it. 21:37 <@sulix> On the morrow, then! --- Day changed Fri Jul 25 2014 11:24 < matches> I'm at UCC 11:39 <@sulix> Okay, I'll show up once I've sorted out this acedemic record stuff. 12:05 < matches> I went to ECM but apparently just a few other people are having difficulties... 18:24 < matches> So steam browser supports html5 canvas but not keyboard events 18:24 < matches> This seems to happen with a lot of browsers 18:25 < matches> We support html5 canvas (which is pretty much solely designed for web based games) 18:25 < matches> But we don't support any way to actually pass input to the page that doesn't suck 18:25 < matches> (I'm looking at you Safari) 18:31 < matches> It sort of spoils the "HTML5 is AWESOME" message the HTML5 people are aiming for 18:31 < matches> The best bit of html5 is and that you no longer need to use html because you can just draw everything in the canvas... 18:32 < matches> Which is scarily similar to using PostScript --- Day changed Mon Jul 28 2014 10:05 < matches> In 2.07 now 10:07 < matches> You removed SDL from contrib 10:07 < matches> So now it won't compile on the lab machines 10:07 * matches gets out the laptop then --- Day changed Tue Jul 29 2014 09:59 < matches> I seem to have this bizarre illness 10:00 < matches> Where half my head feels fine 10:00 < matches> And the other half feels like I've been trying to read brainfuck 10:00 < matches> I hope you don't catch it 10:00 < matches> The side that is sick is the side that was closest to the group hug 10:00 < matches> Coincidence!? 10:00 < matches> I think not! 10:08 < matches> You know how there's this theory about the two halves of the brain being semi independent and sort of subconsciously able to think by themselves 10:08 < matches> I think the left side of my brain is dead 10:08 < matches> It's not responding to pings 10:09 < matches> I think the project working side might be the alive one though, so we shall see if I can actually do something useful --- Log closed Tue Jul 29 23:13:08 2014 --- Log opened Wed Jul 30 12:03:38 2014 12:03 -!- matches [matches@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf 12:03 -!- Irssi: #ipdf: Total of 2 nicks [1 ops, 0 halfops, 0 voices, 1 normal] 12:03 -!- Irssi: Join to #ipdf was synced in 0 secs 16:28 -!- sulix [sulix@motsugo.ucc.gu.uwa.edu.au] has quit [Ping timeout: 121 seconds] 17:25 -!- sulix [sulix@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf --- Day changed Sun Aug 03 2014 12:43 < matches> So I found my moronic mistake with the virtual FPU and it seems to actually work 12:44 < matches> I think it's even slower than using Rational 12:44 < matches> Unless everything's slow because of the QT now 12:45 < matches> There's an awful lot of "Rendering QT node" debug 12:46 < matches> No its the VFPU that makes sense 12:47 < matches> Since every floating point operation now requires writing 18 hex characters over a unix domain socket 12:47 < matches> Hooray VHDL 12:48 < matches> (I'm sure if you have $$$$ and like Enterprise(TM) software VHDL is great) 12:48 < matches> I'll just do some miscellaneous things and hopefully some of them will be useful 12:48 < matches> Bye 14:14 < matches> So with the VFPU and doing everything on the GPU we have 2.2 FPS 14:14 < matches> It seems to be able to cope with rectangles on the CPU 14:15 < matches> The circle may present some difficulties 14:16 < matches> It would be have been pretty cool to change the vfpu and see if anything makes it look like intel 14:16 < matches> But ultimately useless I suppose 14:37 < sulix> There might be some info in the hardware docs, though they're pretty incomprehensible: https://01.org/linuxgraphics/documentation/2013-intel-core-processor-family 14:38 < sulix> AMD also have manuals: http://developer.amd.com/resources/documentation-articles/developer-guides-manuals/ 14:38 < sulix> nVidia are sworn to secrecy. --- Day changed Tue Aug 05 2014 12:38 < matches> I'm looking at the atril source 12:38 < matches> To see if I can compile it without the oppressive 400% max zoom 12:39 < matches> It is rather intense 12:39 < matches> I think the zooms are set depending on the language? 12:41 < matches> There are po files which are definitely not position independent object files 12:43 < matches> #define ZOOM_MAXIMAL(zoom_levels[n_zoom_levels - 1].level) 12:43 < matches> The plot thickens! 12:45 < matches> Heh this is actually sort of making sense 12:45 < matches> They have a "cut-n-paste/zoom-control" directory 12:48 < matches> I'm confused as to how the maximum zoom is 6400% and yet my version will only zoom to 400% 12:48 < matches> But I guess I shall compile it from source and see what actually happens 12:51 < matches> They also have a script to configure their configure script... 12:51 < matches> Oh dear xml is involved 12:53 < matches> There needs to be a way to save the status of configure so you don't have to rerun it from scratch every time you fix an error 12:56 < matches> Our document viewer may only be able to render beziers and circles 12:56 < matches> But at least it doesn't have any dependencies! 12:56 < matches> Well many 12:56 < matches> I suppose since SDL is in contrib we should put GMP in contrib too 12:57 < matches> But yes, I don't care about caja plugins dammit I want to zoom on a pdf 13:00 < matches> "Warning: Comparison between pointer and integer" 13:00 < matches> Aaaah 13:00 < matches> It compiles... 13:01 < matches> But where did it put the binary... 13:02 < matches> Oh great it expects things to be in /usr 13:03 < matches> I guess I will run "install-sh" and hope I will still have a usable pdf viewer 13:07 < matches> There's a LOT of G_ and g_ variables 13:07 < matches> Actually functions 13:07 < matches> I think g_ does not mean global in this context 13:07 < matches> Maybe 13:11 < matches> So it's not just a matter of ZOOM_MAXIMAL being redefined to ridiculously huge numbers having any effect 13:11 < matches> I guess they use some other library that has zooming 13:13 < matches> It somehow detects what the maximum zoom should be based on the document as well 13:13 < matches> This is just over engineering! 13:19 < matches> ev_view_can_zoom_in (EvView *view) 13:19 < matches> return view->scale * ZOOM_IN_FACTOR <= ev_document_model_get_max_scale (view->model); 13:19 < matches> Let 13:19 * matches casually makes it return true 13:19 < matches> Also wtf 13:19 < matches> They have a "gboolean" type 13:19 < matches> Is "bool" inferior? 13:19 < matches> What more do you need than true and false 13:20 < matches> Is bool used as a variable name for something 13:20 < matches> sigh 13:24 < matches> No ok it still won't let me zoom in more 13:25 < matches> g_return_if_fail in the zoom functions 13:25 < matches> They don't look important 13:28 < matches> There are a surprising amount of places with a "if zoom or scale is bigger than the maximum, return" 13:28 < matches> Like, are three checks really necessary 13:29 < matches> I think you can set model->sizing_mode to "EV_SIZING_FREE" but I have no idea what that will do 13:29 < matches> So I'll just continue commenting out anything that looks like it will return early from the zoom process... 13:30 < sulix> Sounds like a plan! 13:31 < matches> The use of g_ for function names makes me want to stab someone :P 13:31 < matches> I assume it's related to gtk or maybe just gnome 13:32 < matches> Also about half their doubles are "gdouble" 13:32 < matches> And the other half are "double" 13:32 < matches> :S 13:32 < sulix> gtk had their own crazy, let's implement everything from scratch idea. 13:32 < sulix> They have their own "classes" in C, IIRC. 13:32 < matches> It's pretty object orientated yes 13:34 < matches> Ok I seem to now be able to zoom in a *bit* more and then it just stops drawing things 13:35 < matches> No wait it's just hopelessly slow 13:37 < matches> It also zooms in on the wrong spot and then draws it and then moves the view back to the mouse and draws again 13:38 < matches> But yes, it doesn't cope well with zooming at all 13:38 < matches> I was kind of hoping it would work 13:39 < matches> Maybe if I use a simpler document 13:43 < matches> Congratulations anyway 13:43 < matches> We can zoom further on a circle than atril can 13:44 < matches> Unfortunately the reasons atril can't zoom are probably not related to precision 13:44 < matches> Maybe I need to find some "if zoom > thing don't draw anything" and comment those out too 13:44 < matches> Sigh 14:07 < matches> It is resistant to my valgrind attempts 14:07 < matches> It seems to have spawned 9 processes 14:10 < matches> Oh "atril" is actually a series of hideous bash scripts that load libraries or something 14:12 < matches> You know 14:12 < matches> I'm sure if we tried 14:12 < matches> We could make a less shitty pdf viewer out of our program 14:29 < matches> Interesting 14:30 < matches> "ev_document_render" got called 10.6 Billion times 14:30 < matches> I don't think I changed the view that many times... 14:32 < matches> Ok, so just working on our own viewer is probably better at this point than working out why atril has a heart attack if you zoom 14:33 < matches> I'm going to pretend this wasn't a waste of time... 14:41 < matches> "existing pdf viewers cap the view because otherwise they break due to bugs that aren't actually related to precision" 15:43 < matches> So I suspect the GPU Bezier rendering is buggy 15:44 < matches> Or maybe it's a quad tree thing 15:45 < matches> Or both... 15:46 < matches> I'm pretty sure the appearance of an individual bezier should not depend on what other beziers are in the document :P 15:47 < matches> Yeah there's wierd quad tree shit going on 15:48 < matches> I'm going to try and add some sort of glyph/font like thing 15:49 < matches> It's either that or create hand drawn beziers in the current view 15:50 < matches> But I feel it desperately needs an example of being able to actually zoom in and create something at an "arbitrary" level 18:54 < matches> So we sort of have a very broken, very badly written, SVG parser 18:55 < matches> A bunch of bugs showed up in the bezier rendering 18:56 < matches> Although it might just be fglrx 22:23 < sulix> The GL code is now consistantly broken, rather than sporadically broken. 22:24 < sulix> Trying to render SVGs with it might count as modern art, though. 22:39 < sulix> Man, the buggier the bézier code gets, the more beautiful its output. 22:53 < sulix> Voilà: http://davidgow.net/stuff/ipdf-koch-svg.png 23:11 < sulix> And on the CPU: http://davidgow.net/stuff/ipdf-koch-svg1.png --- Day changed Wed Aug 06 2014 11:00 < matches> That looks amazing! 11:04 < matches> I'm sorry 11:04 < matches> All I seem to do is add bugs :S 11:05 < matches> And XML 11:13 < sulix> I suspect you removed a lot of bugs with the -DQUADTREE_REMOVED. :P 11:14 < matches> It's the bit where parts of my Bezier code have been wrong for more than a month that make me feel guilty :S 11:14 < sulix> The GPU code was wrong in the same way. 11:15 < sulix> Also it used to corrupt all of the memory. 11:23 < matches> So you're not using the koch.svg file? 11:23 < matches> That breaks for me 11:23 < matches> Which isn't surprising considering the svg parsing code 11:24 < sulix> I was using koch1.svg from your Lit Review 11:25 < matches> Oh right 11:25 < matches> koch.svg isn't actually a valid svg file :S 11:26 < sulix> I tried it with a random, complex SVG from the internet, and segfault. 11:27 < matches> Haha 11:27 < matches> Yeah it works 11:27 < matches> We can zoom in further than atril! 11:28 < sulix> Victory! 11:34 < matches> So I was trying to think about shading things... and stroke thickness... and all those other things in SVG... 11:34 < sulix> Yeah, I thought about those. 11:35 < sulix> I came to the conclusion that I should probably try to make the quadtree work first. 11:37 < matches> Probably :P 11:58 < sulix> btw, your computer's clock is slightly out. 11:58 < sulix> alternatively there is a lot of time travel going on 11:58 < sulix> (secretly, I'm hoping it's the latter) 11:59 < sulix> (im my mind, I'm good enough to have bugfixed the SVG code before it was written) 17:10 < matches> Yeah I removed ntpd because my boot kept stalling at it for several minutes 17:17 < matches> The GPU Bezier renderer seems a lot more conservative about how many lines it uses 17:18 < matches> I thought I remembered just copying the GPU algorithm for the CPU but maybe I didn't 17:20 < matches> Oh 17:38 < matches> Some of the shader stuff confuses me... 17:38 < matches> Like: "pixize = vec2(pixel_w/bounds_w, 100*pixel_h/bounds_h)" 17:39 < matches> Random factor of 100 ? 17:39 < matches> As far as I can tell pixel_w,pixel_h is always 640,480 17:57 < matches> Hmm 17:57 < matches> But the window isn't 640,480 17:57 < matches> Wait 17:57 < matches> Is it 17:58 < matches> Yeah 17:58 < matches> The screen is 800 x 600 17:58 < matches> That is only slightly confusing... 17:58 < matches> Should I change all the 640,480 to 800,600 ... 17:59 < matches> Or will this break things 18:01 < matches> We are actually passing the width and height of the viewport around so I figure that should probably be used instead of 640 and 480 18:02 < matches> Also I suspect we want just a few more lines on the beziers since they often start looking more like trapezoids 18:04 < matches> But only if they are big to begin with 18:05 < matches> We can probably also do a "if x1,y1 == x2,y2 just use one line" 18:06 < matches> Or alternately actually implement lines as distinct from beziers but that's silly :P 18:06 < matches> If I can work out how to do shading then we won't even need rectangles and circles any more 18:06 < matches> I should probably focus on precision of things but I sort of want to be able to draw something cool first 18:15 < matches> Oh damn merge 19:19 < matches> So a series of curveto commands isn't just a series of individual beziers for each three points 19:20 < matches> I guess it's time to actually read the SVG spec a bit 19:20 < matches> Oh maybe they are cubic beziers 19:21 < matches> I thought they were just quadratic unless you used a special command 21:08 < matches> The order of your coefficients in the bezier geometry shader seems reversed... 21:08 < matches> But maybe that's because I reversed it in the CPU first... 21:08 < matches> I don't know 21:08 < matches> I will leave it in this order and hope it doesn't break 21:08 < matches> (I'm making the beziers cubic because it seems like a thing we want) 21:08 < matches> And is required for SVG paths 21:27 < matches> Hmm 21:27 < matches> SVGs also have quadratic beziers and as much as setting (x3,y3) == (x2,y2) *almost* looks the same... 21:29 < matches> Close enough I guess 21:30 < matches> I don't particularly want to add seperate objects for quadratic beziers since I've only ever seen cubic ones in SVGs anyway 21:49 < matches> http://szmoore.net/ipdf/svgshape.png 21:49 < matches> Woo! 21:50 < matches> I'm actually pretty excited about having a semi usable svg viewer that can zoom, if not indefinitely, a lot further than any of the open source image viewers will let you zoom :P 21:51 < matches> Shading... that's hard 21:51 < matches> Stroke thickness is kind of hard too... 21:51 < matches> Blergh 22:22 -!- sulix [sulix@motsugo.ucc.gu.uwa.edu.au] has quit [Ping timeout: 121 seconds] 23:42 -!- sulix [sulix@motsugo.ucc.gu.uwa.edu.au] has joined #ipdf --- Day changed Thu Aug 07 2014 21:24 < sulix> So it turns out ttf fonts were not very difficult to add at all: http://davidgow.net/stuff/ipdf-ttf.png 21:42 < sulix> And fixed the glyphs.svg rendering: http://davidgow.net/stuff/ipdf-glyphs.png 22:06 < sulix> So all of those Béziers make Gmpint very slow. 22:07 < sulix> It also runs out of memory very quickly. 22:11 < sulix> About 30 second of dragging an svg around uses ~15G of ram. 22:13 < sulix> It takes (with Rational CPU rendering) ~10 G to render the default frame of glyphs.svg 22:18 < sulix> Okay, it just broke a computer w/ 32 GB of ram. 22:20 < sulix> Code is pushed, btw, for your computer-wreckingly-awesome enjoyment. 22:32 < sulix> I tried fixing Rational::ToDouble() and using GPU w/ CPU coordinate transform. 22:32 < sulix> Still runs out of memory. 22:33 < sulix> But it works, even if it's still a tad slow. 22:45 < sulix> Okay, memory use is not a problem at all if we delete out GMP integers after we're finished with them. 22:46 < sulix> (There was a TODO: to that effect) --- Day changed Fri Aug 08 2014 16:11 < matches> Wait you just did the things *I* was supposed to do for this week :P 16:11 < matches> I hope you don't want me to fix quadtrees... 16:13 < matches> Ah sorry about the GMP 16:14 < sulix> I gave the QuadTrees another go as well, but random half-letter-"b"s were everywhere. --- Day changed Mon Aug 11 2014 10:56 < matches> Ok I think I need to throw all design principles out the window adding a keyboard handler 10:57 < matches> I know you were keen on having a mouse handler independent of the Screen class 10:57 < matches> But the Screen class detects the events 10:57 < matches> It really makes sense for the event handlers to just be member functions 10:57 < matches> Maybe virtual in the unlikely event that there are ever different types of Screen 10:58 < matches> Probably the View should handle the events 10:58 < matches> Then we wouldn't have this convoluted thing where View has a reference to a Screen but Screen has a pointer to a View... 10:59 < matches> But I need to let that go and actually do useful things 10:59 < matches> So KeyboardHandler is now a member of Screen 10:59 < matches> Delicious spaghetti 11:02 < sulix> I think I can bring myself to forgive you. :) --- Day changed Tue Aug 12 2014 13:48 < matches> I can draw rabbit_simple.svg 13:48 < matches> ! 13:48 < matches> Almost 13:50 < matches> IT IS BEAUTIFUL 13:52 < matches> Wait I think quad trees are enabled 13:53 < matches> Nope they aren't 13:53 < matches> Oh wel 13:54 < matches> http://szmoore.net/ipdf/infinite-precision-document-FOX.png 13:54 < matches> That didn't take very long 13:55 < matches> I suspect the wierd bits in the wrong spot are because there are translations applied to things 13:55 < matches> Because inkscape 13:57 < matches> Hmm yeah 13:58 < matches> I wonder why there are random straight lines between things though 13:58 < matches> They are filled regions of the same colour and no stroke but obviously we just read the beziers and draw the outlines 14:50 < matches> Dammit SVG 14:50 < matches> So the y coordinate of text refers to the bottom 14:50 < matches> The y coordinate of *everything* *else* refers to the top 14:51 < matches> It's alright this is ipdsvg we aren't constrained by stupid standards 14:59 < matches> Ergh somehow fonts are broken in eye of mate... 14:59 < matches> How did I even... 15:00 < sulix> Fonts are usually handled with y=0 being the "baseline" of characters. 15:10 < matches> There are a few wierd things going on with straight lines 15:11 < matches> Hmm only at the default zoom 15:11 < matches> Horizontal lines on both cpu and gpu are kind of wobbly 17:23 < matches> Ok I am suffering from an attack of matrix algebra 17:23 < matches> It was bound to happen sooner or later I guess 17:24 < matches> The spaghetti is cooking nicely 17:26 < matches> The fact that our document is all in GL coordinates and SVGs are not is causing me way more confusion than it really should be 17:27 < matches> All I need to do is set an initial transformation matrix then everything else should Just Work 17:27 < matches> Of course it does help if you actually use matrices instead of Rect's 17:29 < matches> Also I think functions that modify arguments passed by references is one of the things that tpg hates 17:29 < matches> But there are a lot of them here 17:29 < matches> They are so convenient! 22:03 < matches> If I can get transforms and groups actually working properly, we can probably hack some sort of recursive thing together and use view reparenting 22:03 < matches> Somehow 22:05 < matches> I'm thinking putting the fox in the rabbit's eye and so on recursively would actually be pretty damn awesome 22:05 < matches> It is easy to say these things though... 22:06 < sulix> So, I have view reparenting "working" in the quadtree code. 22:06 < matches> :O 22:06 < matches> Cool 22:06 < sulix> (The rest of the quadtree doesn't work, so the point is somewhat moot, though) 22:06 < matches> Wait you already had that working, but you have rendering bugs 22:06 < matches> Yeah 22:06 < matches> :P 22:08 < sulix> I will push that now, actually. --- Day changed Wed Aug 13 2014 00:34 < matches> Yes 00:34 < matches> I have defeate 00:34 < matches> d 00:34 < matches> Basic matrices 00:36 < matches> So it is pretty ugly and inefficient but meh 00:36 < matches> We have translate, scale and matrix 00:37 < matches> skew will be pretty easy to add but probably useless 00:37 < matches> rotate is a bit harder 00:38 < matches> Also the skewing operations obviously don't work on rectangles 00:38 < matches> Or anything that isn't defined in terms of bezier paths I guess 00:38 < matches> But translating and scaling will 00:40 < matches> Ok, so SVG has a "defs" thing that lets you define groups without drawing them 00:41 < matches> And a "use" thing that lets you insert a group 00:41 < matches> Actually element in general 00:41 < matches> Doesn't have to be a group 00:41 < matches> So 00:41 < matches> I wonder if doing recursive magic with that works 00:48 < matches> Not in normal svg viewers it would seem 00:49 < matches> Hmm 00:51 < matches> (eom:7883): librsvg-WARNING **: Circular SVG reference noticed, dropping 00:51 < matches> That's just boring! 00:52 < matches> So I think we will need some fairly major changes to our Document structure to get much more SVG stuff working 00:53 < matches> I wonder if we actually need to store a DOM if we want that to work 00:53 < matches> Also I thought I fixed transformations but they still break for fox-vector.svg :( 00:58 < matches> I think "broken" will probably be the most commonly occuring word in our git commit messages 11:05 < matches> Oooh 11:06 < matches> svg-tests/recursive.svg is slightly recursive viwed in firefox 16:10 < sulix> The QuadTree works again! 16:10 < sulix> (I have finally worked out how to multiply by two, it seems...) 16:11 < sulix> Also s/ again// 17:23 < matches> Project complete! 18:05 < sulix> Man, nVidia has an OpenGL extension where you can just pass the "d" attribute of SVG paths in and have it render them for you. 18:05 < matches> Oh 18:05 < matches> Welp 18:07 < sulix> It's like: glPathStringNV(path, GL_PATH_FORMAT_SVG_NV, strlen(d), "M100,180, L40,10, etc...") 18:08 < matches> Presumably you could just replace 90% of the SVG stuff with that then :S 18:09 < sulix> It only works on nVidia hardware, though, so it's not really practical. 18:10 < matches> I think I need to actually do the Bezier's bounding rectangles correctly 18:10 < sulix> I was just about to add that, actually. 18:10 < matches> But its not just (x0,y0,x3-x0,y3-y0) 18:10 < matches> Ok 18:10 < matches> Go ahead then 18:10 < sulix> Nah, you have to take the x and y components separately and solve for min and max. 18:11 < matches> Yes google is a lot faster than actually doing maths 18:13 < matches> I can add that unless you've already written it? 18:13 < sulix> Sure. 18:13 < sulix> The internet seems to claim that you should use newton-raphson to find the roots of the derivatives, but I'm not really comfortable with doing that for cubic béziers, 18:31 < matches> I just differentiated the parametric formula 18:31 < matches> And got a quadratic 18:31 < matches> Unfortunately there is a slight problem with Real 18:31 < matches> Since we don't have a general "sqrt" 18:31 * matches adds that to the growing list of "fix later" 18:32 < matches> It doesn't compile for Rational anymore anyway 18:38 < matches> I am writing code that sjy would probably not consider elegant 18:50 < matches> Well that totally broke everything 18:53 < sulix> So it turns out that the view reparenting was only working by chance. 18:55 < matches> :( 19:20 < matches> Hmm it turns out finding the bounding box of a bezier has really annoying edge cases 19:43 < sulix> Okay, automatic generation of new quadtree nodes "works" when zooming in. 19:44 < sulix> It doesn't do any fancy clipping, so the actual rendering code hits precision issues, but it's still pretty cool. 19:48 < sulix> It also get a bit buggy if you try to pan over the edges of quadtrees, as it only renders one node at a time. 19:59 < matches> Nice 21:14 < sulix> I have just achieved infinite precision with the quadtree! 21:14 < sulix> Only on rectangles, only when zooming in, and only when the camera doesn't cross a quadtree boundary, but it works! --- Day changed Thu Aug 14 2014 09:50 < matches> cool 10:37 < matches> I'm beginning to suspect whoever said to use the Newton Raphson method to find Bezier bounding boxes was right 10:43 < matches> I love how the sites I looked up said "Obviously there is a problem if a = 0 or b^2 - 4ac < 0, but we can just make sure we always pick beziers that don't cause those problems 10:44 < matches> Ok 10:44 < matches> I have at least got an algorithm that returns finite sized bounding boxes now 10:45 < matches> I think it even works! 10:45 < matches> But only on the CPU 10:45 < matches> Presumably the GPU does something to cope with the fact that the bounding boxes were totally wrong before? 10:53 < matches> Oh it wasn't doing anything because they were {0,0,1,1} 10:54 < matches> I have to transform the Bezier coefficients before they are uploaded to the GPU 10:54 < matches> Blergh 10:55 < matches> What I've basically done is change it to be the opposite of how it was designed 10:55 < matches> -_- 10:56 < matches> So before, the Bezier control points were relative to some bounding rectangle but when I parsed the SVG I just made it always {0,0,1,1} so the coordinates were absolute 10:56 < matches> Now I have changed the Bezier control points to be absolute and then calculated a bounding rectangle from them 10:56 < matches> I can maths 10:57 < matches> So I could make the Beziers still have the {0,0,1,1} bounds which will fix the GPU renderer without having to transform the coefficients 10:57 < matches> And just leave this "SolveBounds" function in for actually getting the bounds 10:58 < matches> Except SolveBounds is disgusting 10:58 < matches> And slow 10:58 < matches> So I could add a Bounds member variable to the Beziers 10:58 < matches> And then we have two bounds 10:58 < matches> I seem to have coded myself into a catch 22 "No matter what you do it is terrible" situation 10:59 < matches> Adding a Bounds member variable to the Bezier struct sort of defeats the whole point of the "Object of Arrays" idea 10:59 < matches> You know what 11:00 < matches> I think the "Object of Arrays" approach has caused more problems than it solved :P 11:02 < matches> (Probably not actually) 11:09 < matches> Spaghetti 11:09 < matches> I'm going to transform the coordinates before uploading to the GPU shaders 11:09 < matches> Because I think that is the least objectionable? 11:09 < matches> I don't know 11:09 < matches> I still don't like any of the solutions 11:10 < matches> But having more than one bounding rectangle definitely seems dumb 11:10 < matches> Especially if the other is *always* {0,0,1,1} 11:11 < matches> I hope this doesn't totally break your quad tree 11:15 < matches> Actually looking at the quad tree it seems that is the best way to make it more likely to work 11:21 < matches> I feel like we should use SVGMatrix more and Rect less 11:21 < matches> But oh well 11:29 < sulix> Ah: so the Quadtree kinda relies on the Bézier coordinates being relative to the bounding rectangle. 11:29 < matches> Yep 11:29 < matches> I'll do that 11:29 < matches> It's easier to do the transform when the coordinates are uploaded to the GPU 11:29 < matches> Although probably less efficient 11:30 < matches> On the other hand, the CPU renderer relies on having absolute coordinates 11:30 < matches> Two renderers 11:30 < matches> TWICE the matrices 11:30 < matches> TWICE the confusion 11:31 < matches> And Rects are not really convenient because they aren't a proper transformation matrix 11:31 < matches> I can't just multiply some Rects together 11:31 < matches> Or calculate an inverse 11:32 < sulix> Yeah, there are problems there. 11:34 < matches> Hmm 11:34 < matches> I *almost* fixed it 11:34 < sulix> Rects are really good for the QuadTree, though. 11:34 < matches> We should leave it as rects 11:34 < matches> You just manually work out what it needs to be anyway 11:35 < matches> I think the inverse of the equivelant matrix will always work as a rect 11:35 < matches> So there are random lines missing from the beziers now 11:35 < matches> But the ones that are there are in the right spot! 11:36 < matches> (On the GPU) 11:36 < sulix> So, I looked at that. I see random missing lines on Intel, not on nVidia. 11:37 < matches> Oh were they missing before? 11:37 < matches> Well I don't recall them being missing before 11:37 < matches> Oh 11:37 < matches> I know what it is 11:38 < matches> When the bounding rectangle has width or height of zero 11:38 < matches> Sigh 11:38 < matches> Wait that can't be it 11:38 < matches> Most of the missing lines aren't straight horizontal or vertical 11:38 < matches> :S 11:39 < sulix> I think it's just dodgy rounding on the GPU. 11:40 < matches> I will push what I have I guess 11:40 < matches> I have nice pretty debug rectangles (in *colour*) around the beziers when they are rendered on the CPU 11:40 < matches> Somehow I don't think that is going to be sufficiently impressive progress in the meeting 11:41 < sulix> Oooh... I'm looking forward to trying that. 11:41 < sulix> I have an impressive Quadtree demo to do! 11:41 < sulix> Assuming the bezier stuff doesn't suddenly break. 11:41 < matches> ... it might 11:41 < matches> Ok, I will `git stash` and then `git pull` as opposed to merging 11:42 < matches> Yes, there are definitely not randomly missing beziers in your code 11:44 < matches> Wait, was your quad tree working with beziers before? 11:44 < matches> It wouldn't have been? 11:44 < matches> All the bounds were wrong 11:48 < matches> Ooh 11:48 < matches> H and V 11:48 < matches> What are they 11:49 < sulix> Horizontal and Vertical lines 11:49 < matches> Ah 11:50 < sulix> The QuadTree works with beziers, but doesn't increase precision. 11:52 < matches> Hmm, now to work out which of the 5 or 6 edge cases is breaking the Bezier bounds algorithm 11:53 < matches> It's kind of hard to debug 11:53 < matches> The edge cases apply seperately to the y and x directions 11:53 < matches> So you can't tell just by looking at a curve that it is an edge case 11:54 < matches> Unless you are a mathemagician I guess 11:55 < matches> I don't understand 11:55 < matches> The bounds for the beziers that disappear look right 11:59 < matches> Maybe I'm not uploading the data correctly anymore 12:03 < matches> Ok now it only breaks for the horizontal and vertical lines which I at least understand 12:03 < matches> I was iterating over the object bounds and uploading the ones that had a type of BEZIER 12:03 < matches> Oh 12:03 < matches> Oh 12:04 < matches> Yeah because I added a GROUP as well 12:04 < matches> And every gets a GROUP now 12:04 < matches> So the order of indexes must be off 12:14 < matches> Face palm 12:14 < matches> This is why we have objects.data_indices 12:19 < matches> I wish I'd added the SVG stuff earlier 12:19 < matches> It makes it a lot easier to do stuff when you can mess around with actual documents 12:42 < matches> I have pushed some stuff 12:43 < matches> Mostly it just looks like I added a bunch of colourful rectangles to the CPU rendering 12:43 < matches> I think I broke the Quad tree too 12:43 < matches> Go team 12:43 < matches> Oh and there are a bunch of not so colourful GPU rectangles 12:43 < matches> Due to the "GROUP" object just using the outline rectangle shaders 12:44 < matches> So part of the quad tree seems to work on the GPU but not all of it 12:44 < matches> And none of it seems to work on the CPU? 12:48 < matches> Also instead of rendering a slightly broken fox it now renders a segfault 12:48 < matches> Similarly for the koch snowflake 12:48 < matches> It's alright we can still draw Humphrey 12:53 < matches> Oh 12:53 < matches> It's just the quad tree that segfaults on the more complicated svgs 13:38 < sulix> I have returned from the committee meeting, and that stupid 2/3rds majority thing has been revoked! 13:38 < matches> Hooray! 13:39 < matches> I should head towards University for the project meeting 13:39 < matches> It is tempting to just stay home 13:40 < matches> But that would probably not be wise 13:41 < sulix> You should come. 13:41 < sulix> I'm going to see if I can fix the Quadtree, but it looks like your changes have thoroughly broken it. 13:41 < matches> Sorry! 13:41 < sulix> By which I mean, it probably was only working if everything had bounds (0,0)-(1,1) 13:41 < matches> Haha 13:42 < matches> You can just undo my changes to demonstrate it if you want 13:42 < matches> To the bus 13:43 < sulix> I may yet do that... 14:54 * sulix -> CSSE 19:08 < matches> So shading on the CPU sort of totally breaks 19:08 < matches> But it exists 19:08 < matches> Progress! 19:10 < matches> Bezier bounds are not as good as I'd hoped 19:10 < matches> I think they only work if the end points form the bounds 19:17 < sulix> Ah... 19:21 < sulix> Btw, in the default "c" glyph, there are _two_ curves with bounds (0,0)-(1,1) 19:21 < sulix> Numbers 9 and 18 19:22 < matches> Yeah I found the wierd ebounds 19:22 < matches> It's in the font code 19:22 < matches> There is an AddBezierData with (0,0,1,1) instead of AddBezier (which automatically works out the bounds) 19:22 < matches> For vlines 19:22 < sulix> That'd do it. 19:23 < matches> shape.svg seems to lose part of the curve now 19:23 < matches> I've made the bezier control points relative 19:23 < matches> Things mostly sort of work 19:23 < matches> But the quad tree still looks fantastically broken 19:25 < sulix> It always looks broken if you pan around or zoom out: it's my ugly baby. 19:28 < matches> http://szmoore.net/ipdf/brokenbeziers.png 19:28 < matches> To be fair the beziers are actually fine 19:28 < matches> It's just the bounding rectangles that are broken 19:28 < matches> Also shading should probably not be turned on unless it is actually a closed path 19:29 < sulix> Hmm... 19:29 < matches> Wait 19:29 < matches> The beziers are rendering fine 19:29 < matches> But the bounding rectangles are wrong 19:29 < matches> Does this mean 19:29 < matches> If I *fix* the bounding rectangles 19:29 < matches> It will break something 19:29 < matches> :-( 19:29 * matches forges ahead nevertheless 19:30 < matches> It does look suspiciously like it is only ever using P0 and P3 for the bounds 19:30 < matches> Despite all that horrible solving for the turning points 19:31 < sulix> Yeah. 19:31 < matches> Oh 19:32 < matches> I suspect if I fix this it will totally break the absolute to relative bezier transform then 19:35 < matches> The file for those beziers is kind of interesting 19:35 < matches> inkscape has used absolute commands for all except one of the beziers 19:35 < matches> Why? 19:35 < matches> The first one was copied and pasted with the control points moved 19:35 < matches> Also for some reason random "translate" applied to the whole group 19:36 < matches> It might make some sense if it caused the coordinates of the actual paths to come out as integers maybe 19:36 < matches> But they don't 19:37 < matches> There is translate and then the initial "moveto" is not 0,0 19:37 < matches> I guess we shouldn't be trusting an svg editor that segfaults if you try recursion anyway 19:59 < matches> Ok, high school maths:1, 5th year science/engineering student:0 20:15 < matches> Also my amazingly clever shading algorithm has 20:15 < matches> ... 20:15 < matches> issues 20:15 < matches> When the paths are not in the view 20:16 < sulix> Ah... 20:18 < matches> In fact it has many issues in many cases 20:27 < matches> Hmm 20:27 < matches> I wonder if this is what causes problems with evince/atril 20:27 < matches> Ok not this 20:28 < matches> I mean, if they use a similarly terrible except actually working shading algorithm 20:28 < matches> And just draw everything to a really big texture so they can use it 20:28 < matches> As opposed to clipping things 20:28 < matches> That seems a little unbelievable though 20:29 < matches> Surely that would crash long before you even got to >1600% 20:30 < matches> I suppose what I should really do is look up some papers on shading 20:30 < matches> Blergh 20:35 < matches> Things are pushed 20:37 < matches> Ah crap 20:38 < matches> Things will be pushed in 8 hours according to my clock 20:38 < matches> Just don't do anything until after 4am tomorrow and everything will be in the right order 20:38 < matches> :P 20:39 < sulix> That shading is _amazing_ 20:40 < matches> Try replacing the colour with rand()%255 for even more amazingness 20:40 < sulix> If you zoom in _just_ the right amount, all hell breaks loose. I love it! 20:40 < matches> Haha 20:40 < sulix> Slowly panning across it is also magical! 20:41 < matches> Try it on rabbit_simple.svg 20:42 < sulix> I think Humphrey might have come down with a case of stripey binary myxomatosis. 20:43 < matches> So I will have to think about shading a bit more :P 20:43 * sulix braves the unholy combination of shading and quadtree. 20:43 < matches> Oh I didn't try that 20:44 < sulix> It actually doesn't look any different. 20:44 < sulix> I think the quadtree only breaks w/ the GPU. 20:44 < matches> Yes 20:45 < matches> You lose the debug message if the node # > 9 it seems too 20:46 < matches> At least the quad tree works on the CPU 20:46 < matches> But why doesn't it work on the GPU they are now using the same bounds 20:47 < matches> So should I prepare a report for Tim? 20:47 < matches> Progress Report: Arbitrary precision numbers are unsurprisingly, totally infeasible 20:47 < matches> Therefore, we implemented random bits of SVG 20:47 < matches> Figure 1: A totally broken shading algorithm 20:48 < sulix> You should include this image of the quadtree: http://davidgow.net/stuff/ipdf-humphreys-ghost-face.png 20:48 < matches> Yes 20:48 < matches> I wonder if since we're allegedly engineers we should document what bugs go with what images 20:48 < matches> Hmmm 20:49 < sulix> That's why I name the screenshots like that, I know this goes with the "Humphrey's Ghost Face" bug. 20:49 < matches> Haha 20:49 < matches> So we have the svg-test images 20:50 < matches> Would it be worth while to have a commit script that automatically drew them and did screnshots 20:50 < matches> It might be tricky though because you have to test panning and zooming and things 20:50 < sulix> Yeah... perhaps videos? 20:51 < matches> We'd need to be able to control the view automatically 20:51 < matches> Which is actually required for that list of things in the proposal we are supposed to do anyway 20:52 < sulix> I think we'll want that feature at some point anyway for doing proper performance tests 20:54 < matches> I kind of want some sort of debug overlay for things like the bounding boxes too 20:54 < sulix> Hmmm... the bounds look right: http://davidgow.net/stuff/ipdf-humphrey-bounds-ahead.png 20:54 < matches> And a menu system 20:54 < matches> And the ability to "insert SVG here" 20:54 < matches> And open a file browser 20:54 < matches> And... 20:54 < matches> And... 20:54 < matches> Yeah 20:54 < sulix> I've been seriously considering doing a menu system. 20:54 < matches> Too bad christmas is after the thesis is due 20:54 < matches> Do it! 20:55 < matches> We're running out of mouse buttons to toggle things :P 20:55 < matches> Are there any SDL based menu systems that we can use easily? 20:55 < sulix> There are a couple of OpenGL-y ones that might work. 20:56 < matches> Let's not port the project from SDL -> FreeGlut 20:56 < sulix> No. 20:56 < sulix> Let's not. 20:57 < sulix> (I'm looking for an SDL/OpenGL menu system so that I can replace FreeGLUT in the Graphics project( 20:57 < matches> Could we use Qt or is that overkill? 20:57 < sulix> I suspect it's probably overkill. 20:59 < sulix> I've got a couple of old GUI libraries for SDL/OpenGL I wrote in high school I could dig up as a last resort. 20:59 < matches> ... I have seen your high school code 20:59 < matches> :P 20:59 < sulix> (I think one of them uses a tiny bit of boost, though, so I'd rather avoid it) 21:03 < matches> I kind of want to look at Qt at some point 21:03 < matches> Maybe if we have the menu in a seperate window... 21:03 < matches> Then we need threads... 21:03 < matches> Then we have two problems... 21:09 < matches> All the links to SDL libraries are broken 21:34 < sulix> I'm not sure what changed, but now ipdf crashes my OpenGL debugger. 21:42 < sulix> The QuadTree/GPU code works again! 21:42 < sulix> Somehow the bug I fixed last night reappeared, but I've added the needed *2s back in. --- Day changed Fri Aug 15 2014 08:43 < matches> So it seems to work well but things still go wierd on the GPU 08:44 < matches> I'm in Quadtree node 32 looking at the tip of Humphrey's eyebrow 08:44 < matches> The bottom line moves normally 08:44 < matches> Vertically only sorry 08:44 < matches> It doesn't move horizontally 08:44 < matches> The top line stays still and every so often jumps to a new (wrong) position 08:45 < matches> On the CPU it appears fine though 08:45 < matches> Although on the CPU it doesn't show the "Current View QuadTree Node: 32" 08:46 < matches> Hrm, I should add a 2d view of a car to the svg-tests 08:47 < matches> Then I can be like "IT IS RELEVANT TO MECHANICAL ENGINEERING BECAUSE BEZIERS" 08:47 < matches> In the conference/thesis offense 08:48 < matches> My concern is actually more how I'm going to present the arbitrary precision number representations because they don't even work 08:49 < matches> Well I should probably try Gmp rationals and Gmp floats before totally giving up I guess 08:49 < matches> And also those p-adic things 08:50 < matches> I never looked them up --- Day changed Sun Aug 17 2014 14:38 < matches> Hey Qt has a lot of stuff in it 14:38 < matches> They have their own iostreams that seem identical to std::iostream 14:39 < matches> It's kind of cool I guess except there are "Qs" everywhere 14:41 < matches> Ok we need a window icon 14:41 < matches> This is vital 15:54 < sulix> I've got SDL2 window icon setting code if you want it: https://github.com/sulix/omnispeak/blob/master/src/icon.c#L555 16:04 < matches> Cool 16:39 < matches> I'm bringing in spaghetti 16:39 < matches> I mean Qt 16:40 < matches> In theory this means the Debug functions should have a mutex if we want to debug things in the Qt stuff 16:40 < matches> But in practice screw it 16:40 < matches> What could go wrong? 16:41 < matches> (Don't worry, I have a CONTROLPANEL_DISABLED define) 16:42 < matches> This View/Document/Screen thing could probably be tidied up a lot 16:42 < matches> But effort 16:42 < matches> I think I'll just give ControlPanel direct access to document, screen and view 16:42 < matches> Currently everything has to go through view 16:43 < matches> Which would make more sense if some of screen was in view maybe 16:43 < matches> Bah screw design 16:51 < matches> So now we have 4 main classes! 16:51 < matches> 4 x the fun! 17:29 < matches> Bargh Qt needs its own version of make 17:29 < matches> That's stupid 21:09 < matches> So 21:10 < matches> I have a mysterious LMS deadline that suddenly appeared 21:10 < matches> "Progres Report" 21:10 < matches> Description 21:10 < matches> "asadf" 21:10 < matches> Due 21:10 < matches> 19th August, 11:01PM 21:10 < matches> What 21:14 < sulix> Oh dear. 21:15 < matches> I have sent an email 21:15 < matches> I hope that's not the conference abstract 21:15 < matches> I also really hope we're allowed to use our own computer and things in the conference 21:16 < matches> Also I really hope that if I can use my own computer it doesn't decide to shit itself anyway just to spite me --- Day changed Mon Aug 18 2014 17:06 < matches> Good news and bad news! 17:07 < matches> The kerning now appears to kern in the right direction 17:07 < matches> But this means "BleedingCowboys.ttf" works 20:30 < sulix> It's a pain to look up clipping of beziers, because there's a separate technique for doing something else called "bézier clipping" 20:40 < matches> Baha 20:41 < matches> I'm basically just procrastinating with Qt 20:41 < matches> I mean 20:41 < matches> Doing *awesome* things with Qt 20:48 < sulix> I am looking with considerable envy at SolveQuadratic(). 20:49 < sulix> SolveCubic() will get very ugly. 20:49 < sulix> Assuming I don't just sample the cubic at 100 points and look for roots. 20:49 < matches> Haha 20:49 < matches> Newton Raphson? 20:50 < sulix> Very tempting. 20:50 < matches> Then you can solve any bezier! 20:50 < matches> Then we can put in Quintics! 20:50 < sulix> Solving cubics exactly is not fun. 20:50 < sulix> Dear god no. 20:50 < matches> Imagine how many loops a quintic could have... 20:51 * sulix cries quietly in the corner. 20:53 < matches> So I'm calling AddText with sane values and nothing is happening :( 20:56 < sulix> With or without quadtree? 20:56 < sulix> With quadtree, everything is broken if you try adding things. 20:56 < sulix> Because they won't be added to a node. 20:57 < matches> No quad trees I think 20:57 < matches> Yeah no quad tree 21:00 < matches> Wait I think we need to rebuild the buffers or something 21:07 < matches> Ah, ForceRenderDirty() 21:14 < matches> I don't think the scale of our text is quite right? 21:14 < sulix> Well, the scale of everything is wrong, but it's entirely possible that the text is _extra wrong_ 21:16 < sulix> In theory, the "scale" input to addText is the "height" of a character. 21:19 < matches> Mmm 21:19 < matches> I'm trying to add text relative to the current view 21:19 < matches> But it isn't consistent 21:19 < matches> When I go to a different view it is definitely not adding it in the same relative place 21:20 < matches> The scale and positions aren't *already* relative are they? 21:22 < sulix> Not to the view... 21:24 < matches> What are they relative to? 21:24 < matches> Anyway instead of fixing that bug I'm adding more 21:25 < sulix> Umm... The bounding box maybe? 21:25 * sulix investigates. 21:26 < sulix> Scale and position should (I think) be normal, document coordinates. 21:26 < matches> Odd 21:26 < matches> Oh well 21:26 < matches> Having Qt is totally worth it by the way 21:27 < matches> Although it is still slightly embarrassing that it has its own SVG parser 21:27 < matches> Ours is better! 21:27 < matches> It has Reals everywhere! 21:27 < matches> Except where it constructs Real from floats... 21:27 < matches> And converts them to floats... 21:28 < sulix> Thesis title should be "Keepin' it real: Staying afloat on the sea of document precision" 21:31 < matches> Bahaha 21:31 < matches> That is brilliant 21:32 < matches> The Qt stuff is never deleting anything 21:32 < matches> I suppose I should fix that at some point 21:33 < matches> So basically it is a state machine and you use the menu to change the state 21:33 < matches> Pressing OK does something depending on the state 21:34 < matches> And there is a single text edit you can type stuff into 21:34 < matches> In theory it can hide/show different widgets depending on the state 21:34 < matches> I feel like I should add a "Generate Thesis Title" widget now... 21:35 < matches> Also I can sort of see the appeal of lambdas for GUI programming now 21:35 < matches> But I have a feeling they would totally break Qt anyway 21:49 < matches> ... 21:49 < matches> Ok sometimes the text gets added upside down... 21:49 * sulix disclaims any and all responsibility for that. 21:51 < matches> Yes! 21:51 < matches> I finally did that thing I was saying I'd do for like 3 weeks 21:51 < matches> Zoom in to floating point limit 21:51 < matches> Add SVG 21:51 < matches> Watch it explode! 21:52 < sulix> Oooh... 21:52 < matches> It is glorious 21:54 < matches> We need to be a bit careful with thread safety in qt 21:55 < matches> Really we should be able to request that the qt thread call UpdateAll itself 21:55 < matches> Rather than calling it directly from the viewer thread 21:55 < matches> But I'm not sure how that's done 21:55 < matches> There's all this stuff about "Cross thread signals" on the internet 21:56 < matches> It seems you can hide/show things but not much else 22:47 < matches> Bah you pushed things! 22:55 * sulix proclaims the new features as excellent and promptly goes to bed. --- Day changed Tue Aug 19 2014 18:08 < matches> My conference is in the week starting 13th October 18:08 < matches> Is Tim back then? 18:08 < matches> "your supervisor will be invited to attend and mark your presentation" 18:09 < matches> So if he can't go... I don't get a mark? 18:12 < matches> It sounds suspiciously like they are going to get everyone's supervisors to mark them and then just scale everyone :S 18:13 < matches> Surely at least one other person is going to read the final report... 18:13 < matches> I've heard bad things about the engineering scaling system 18:14 < matches> Your mark becomes inversely proportional to how well your supervisor's students did the previous year or something like that 18:15 < matches> Anyway, two months left to accomplish something! 20:05 < sulix> Worked out why the font bounds were weird. 20:06 < sulix> AddText takes (msg, scale, x, y) not (msg, x, y, scale), so the coordinates were all bunk. 20:09 < sulix> Fonts looks _amazing_ with floating pt errors, too. 20:09 < sulix> http://davidgow.net/stuff/ipdf-i-think-you-mean-comic-fail.png 20:29 < sulix> The Art of Computer Programming briefly mentions the Stern-Brocot tree, btw. 20:29 < sulix> I can't see it being really useful, though. 21:06 < sulix> My difficulty clipping bézier paths may be because it is actually impossible. 21:06 < sulix> I think I've just found a paper saying that it is only possible for béziers which happen to be straight lines. 22:55 < sulix> Never mind, it is possible, it's just very nasty. 23:15 < sulix> Also C++14, because we need more lambdas: https://isocpp.org/blog/2014/08/we-have-cpp14 --- Day changed Wed Aug 20 2014 12:05 < matches> I guess we've accomplished the goals for this week's meeting then! 12:05 < matches> (That shading algorithm totally counts as a "first attempt") 12:07 < sulix> I'm about 2/3rds of the way through deriving the reparametrisation of béziers. 12:08 < sulix> It basically just boils down to pages and pages of rearranging polynomials. 12:38 < sulix> I managed to get the qt4/qt5 monstrosity compiling on my laptop. 12:38 < sulix> It has a "moc-qt4" program, which works, whereas "moc" is qt5. 16:28 < matches> I think I need to stop adding this log to git... 23:08 < sulix> matches: But then, how would history record that I've finally got a maybe-correct derivation for cubic bézier reparametrisation: http://davidgow.net/stuff/cubic_bezier_reparam.pdf 23:08 < sulix> (Code is in git) --- Day changed Thu Aug 21 2014 12:57 < sulix> So it turns out that quadtrees are hard, and reparametrising béziers is why. 13:03 < matches> I don't seem to see anything anymore with the quad tree enabled 13:10 < sulix> The quadtree doesn't let you add things in realtime. 13:10 < sulix> Quadtree nodes are immutable once created. 13:12 < matches> Ah 13:35 < sulix> debug: ReParametrise (bezier.h:190) - (0.000000,0.000000),(1.000000,1.000000),(1.000000,1.000000),(1.000000,1.000000) -> (-nan,-nan),(-nan,-nan),(-nan,-nan),(-nan,-nan) 13:36 < sulix> Looking good! 13:54 < sulix> Clearly, the quadtree rendering is now perfect: http://davidgow.net/stuff/ipdf-this-is-definitely-a-fox.png --- Day changed Sun Aug 24 2014 17:51 < matches> ... 17:51 < matches> I am parsing CSS in the SVGs 17:51 < matches> WHAT HAVE I DONE 17:52 < matches> Blame inkscape for always using css to control the properties 17:57 < matches> http://szmoore.net/ipdf/death-by-shading.png 17:59 < matches> Anyway there is a proper "Group" data type like with the Beziers 18:00 < matches> So if you want to cache things related to groups you can put them in that I guess 18:02 < matches> Really it should be called "PATH" not "GROUP" but I vaguely thought it might be able to be used as either --- Day changed Mon Aug 25 2014 10:39 < matches> I was thinking about how to do shading more 10:40 < matches> And I basically arrived at the idea Loop and Blinn have that you kept talking about 10:40 < matches> Except I didn't realise it at first because my version was all using rectangles instead of triangles 10:40 < matches> I think I will try to get my scanline fill to work first though 13:03 < matches> It sort of works 13:15 < matches> ... or not --- Day changed Tue Aug 26 2014 14:25 < matches> I wonder if I'm going to end up just reverse engineering an algorithm that I was too lazy to understand properly 14:26 < matches> I really like the idea of flood fill better than doing insane triangulation maths 14:26 < matches> Surely GPUs can flood fill 14:28 < sulix> I think they can, but either very slowly or only on very new hardware... 14:28 < sulix> I think you'd need to do it in several passes, maybe? 14:28 < matches> The problem I had with flood fill was working out where to start 14:28 < matches> I have something that almost works 14:28 < matches> That requires no clever maths... 14:29 < matches> But it is CPU only 14:29 < matches> And probably breaks in a bunch of special cases 14:30 < matches> It doesn't have precision problems though (once you've drawn the boundary that is) 14:31 < matches> It would still be cool to go through the Loop/Blinn algorithm on CPU and GPU 14:31 < matches> Because that is going to have floating point maths in it 14:31 < matches> flood fill has no floats 14:31 < matches> Therefore it is infinite precision 14:31 < matches> Objective complete 14:32 < matches> Actually I don't think my algorithm is proper flood fill, it's sort of scanline flood fill but not? 14:32 < matches> When in doubt write random code 14:34 < sulix> How are you handling the case where, due to a path being half offscreen it becomes two paths? 14:34 < matches> ... I am not 14:35 < matches> If part of the path is offscreen it is annoying 14:36 < sulix> Hopefully, once some of the quadtree code is more functional, the path clipping code can be used to clip paths to the screen. 14:39 < matches> Compositing is also totally broken because the fill just looks for black pixels 14:40 < matches> But if I can get it doing fonts then that's sort of not totally useless 18:35 < matches> I am very tempted to implement a "Please click on the location to fill this path from" interface at the moment 18:39 < matches> Alright, I have shading somewhat stack overflowing 18:39 < matches> I mean 18:39 < matches> Working 18:39 < matches> * 18:39 < matches> ******** 18:49 < matches> http://szmoore.net/ipdf/shading-the-only-svg-that-doesnt-segfault.png 20:43 < matches> Argh 20:43 * matches stabs coordinate transforms 20:43 < matches> stab stab stab 20:44 < matches> My filling algorithm is to find the 4 extrema of the path 20:44 < matches> And try and flood fill inwards from each one 20:45 < matches> But the extrema pixel coordinates keep transforming to *outside* of the path 20:45 < matches> By one pixel 20:45 * matches stabs 21:52 < matches> I guess I should just actually implement loop and blinn shading 21:52 < matches> Flood fill is not as easy as I had hoped 21:53 < matches> I have to start doing annoying geometry maths to work out what point I can start the flood fill at 21:55 < matches> Sigh --- Day changed Wed Aug 27 2014 22:33 < sulix> Suddenly: ToAbsolute on ToRelative does not give original Bezier 22:34 < sulix> I may need to rethink what my quadtree code is doing to those poor curves. 22:51 < sulix> Never mind, that assertion happens _whenever_ trying to load cubicbeziers.svg. 23:03 < sulix> Oh wow: you should see what happens if you start splitting and reparametrising beziers with bad precision. 23:03 < sulix> 'tis "whacked" 23:08 < sulix> http://davidgow.net/stuff/ipdf-a-slight-curve.png 23:15 < sulix> And the Quadtree infinite precision for béziers now works* 23:15 < sulix> *for some beziers. 23:15 < sulix> * for some large finite value of "infinite" --- Day changed Thu Aug 28 2014 11:35 < sulix> What time is it? It's NaN time! 11:44 < sulix> Ah, so... horizontal lines have a height of zero in their bounds. This makes divides by zero happen in places. 11:48 * sulix apologieses profusely for his latest "break absolutely everything" commit. 11:57 < sulix> Yeah, making divide by zero crash rather than generating NaNs breaks a lot of things. 11:57 < sulix> You'd be surprised by how often we divide by zero. 11:57 < sulix> Mostly in the Quadtree code. 11:58 < sulix> Because, damnit, mathematics can't beat me. 12:20 < matches> Yes, lines have zero width... stupid lines 12:21 < matches> I stopped the segfaults in shading by adding a depth counter to FloodFillOnCPU 12:21 < matches> Which makes interesting shading patterns... 12:22 < matches> I think it's time to fall back to the "Use the second algorithm on Wikipedia" approach 12:23 < matches> I can still use a Flood Fill but hopefully a less segfaulty one 12:29 < matches> I'm not sure about ToAbsolute and ToRelative... 12:29 < matches> I thought they should be inverses but they seem not to be 12:29 < matches> Oh wait, the divide by zero would do that 12:30 < matches> That curve looks cool 12:30 < matches> You should talk about it lots in the meeting 12:31 < matches> For the whole meeting 12:31 < matches> Nothing else 12:31 < matches> Don't mention the total lack of progress I made... 12:32 < matches> How much can I trust SolveCubic? 12:40 < matches> Basically I'm going with randomly picking points until I find one inside the shape then starting a flood fill from that point 12:41 < matches> Checking the pixels for the edges is not feasable 12:42 < matches> If you scan along a bresenham line you could jump over the edge 12:42 < matches> ... I see an "if false" in SolveCubic 12:42 < matches> Slightly worrying 12:43 < matches> Ah 12:43 < matches> I approve of SolveCubic 13:31 < matches> So 13:31 < matches> Did you introduce the floating point exception or did I... 13:45 < sulix> I just did. 13:49 < sulix> SolveCubic may have small problems. 13:50 < matches> Yes I am trying to rewrite it now... 13:50 < matches> I swear we did this in CQM 13:52 < sulix> Solvecubic also sometimes tries to take the square root of a negative number. 13:52 < matches> Yep 13:54 < sulix> I've pushed slightly less broken code. 13:55 < sulix> Ny which I mean slightly more broken. 13:55 < matches> ... 13:55 < sulix> I'm avoiding divide by zeros by "if (denominator = 0) denominator = 1" style shenanigans. 13:56 < matches> I'm slightly scared by the change to Rect::TransformRectCoordinates 13:56 < matches> Oh right 13:56 < matches> Yeah 13:56 < matches> That seems... 13:56 < matches> Scary 13:56 < sulix> It works, scarily enough. 13:56 < matches> Anyway I already ifdef'd the thing out of SolveCubic 13:56 < matches> It's too slow for me though 13:57 < sulix> And by works, I mean I haven't found any issues yet. 13:57 < matches> I am brute forcing a point inside the shape 13:57 < matches> This requires finding the intersections with horizontal and vertical lines for every single bounding bezier 13:57 < matches> Then the "even or odd" test 13:57 < matches> You only have to do it once 14:05 < matches> I think SolveCubic would best be done by doing Newton Raphson or the Shooting Method between the endpoints and the turning points 14:05 < matches> I'll see 14:06 < matches> I'll try implement it and see if it's faster 14:06 < matches> You may have to demonstrate my totally broken shading for me 14:06 < matches> I haven't committed in a while 14:41 < matches> Oh 14:41 < matches> SolveCubic may not have been the bottleneck there... 14:41 < matches> -_- 14:41 < matches> The failure to update the variable for a while loop miiiight be more of an issue 14:44 < sulix> Good, 'cause I'm thinking of "upping the SolveCubic accuracy" a bit. 14:44 < sulix> Anyway... 14:44 * sulix -> CS 14:46 < matches> I've reimplemented SolveCubic 14:46 < matches> In theory it works 14:55 < matches> I reckon Binary Search is the only algorithm I am good at implementing :S 14:57 < sulix> Oooh... 14:57 < matches> What? 18:56 < matches> So, the fact that we are not solving cubics analytically is probably important in terms of precision issues 18:58 < sulix> Yeah, that's why I started trying to solve them analytically and then stopped and cried. 18:58 < matches> :( 18:59 < matches> There is a solution, it's just ugly 18:59 < sulix> Nah: for the Quadtree, it didn't matter much. As long as the error went in the correct direction, you'd just lost a tiny bit of efficiency. 19:00 < matches> Hmm 19:00 < matches> I don't expect shading using arbitrary precision arithmetic will be particularly fast anyway... 19:01 < sulix> Well, ideally most of the work in the shading will be done in screen-space anyway. 19:01 < matches> Yes 19:02 < sulix> And, of course, you don't need infinite precision for that because pixels/integers/etc. 19:03 < sulix> So, fingers crossed, things shouldn't matter too much. 19:03 * sulix realises that that is a maddeningly vague statement. 19:03 < matches> Well 19:04 < matches> I got the fill point to actually be in the correct location by actually solving the intercepts correctly 19:04 < matches> But 19:04 < matches> If you zoom *out* far enough, it can end up no longer inside the shape when transformed to screen space 19:04 < sulix> Okay, new plan. 19:04 < sulix> No zooming out. 19:05 < matches> I wish there were other people in this channel so I could justify putting that in qdb 19:20 < matches> There is a temptation to not require all those references to be const during rendering 19:20 < matches> We might want the Path to be able to alter itself based on the view 19:20 < matches> But I guess we'll take that path when we get to it 19:22 < matches> It might be worthwhile caching Path's for fonts 19:22 < matches> But I'd have to change the coordinates to be relative 19:22 < matches> Too many coord transforms 19:24 < sulix> Yup, that can be the subtitle of the thesis: "Too many coord transforms" 19:26 < matches> "A coordinated approach to graphics" 19:26 < matches> Oh wow 19:26 < matches> That should be a textbook 19:26 < sulix> "Transformers: Matrices in disguise"? 19:30 < sulix> Okay, it turns out (if denominator is zero, make denominator 1) has one flaw. 19:30 < sulix> Sometimes you should make the denominator... negative 1. 19:30 < matches> ... 19:30 < sulix> Somehow, I did not see this coming. 19:30 < matches> I'm not sure how this maths works 19:30 < matches> 1/0 != 1/-1 19:30 < sulix> That's what they want you to think. 19:31 < sulix> (Or maybe the bug I'm having is unrelated to that, but it seems like a fun guess) 21:16 < matches> Floating Point Exception in fglrx! 21:16 < matches> glXDestroyContext 21:16 < matches> It only happens when the program is about to close 21:16 < matches> So I'll be fine 21:18 < sulix> Ah, maybe enabling floating point exceptions was a bad idea. 21:18 < sulix> ...if it causes lots of "fglrxceptions"! 21:21 < matches> Well fglrx is exceptional 21:37 < matches> I'm falling back on just testing a crap tonne of points for "inside" and adding all the ones that are to a vector 21:37 < matches> I think there are some false negatives in Path::PointInside 21:37 < matches> Also FloodFill misses some edge pixels which makes no sense 21:38 < matches> If it's next to a filled pixel it should get filled! 21:47 < matches> So the disadvantage of using a breadth first search is that when your queue gets really big instead of getting a segfault you just get OOM 21:48 < matches> segfaults are quick 21:48 < matches> segfaults are like a pistol and oom is like drowning 21:54 < sulix> There is no way a BFS floodfill should ever OOM 21:54 < sulix> How many pixels are there, and how much are you storing per one? 21:58 < matches> Probably max 256x256 pixels, 4 way fill 21:58 < matches> It does not like rabbit_simple.svg 22:04 < matches> Yeah there is *something* causing it to get in a loop 22:04 < matches> Because obviously my BFS didn't check for loops 22:14 < matches> -_- 22:14 < matches> It is in a loop 22:14 < matches> Because there is a region with fill colour of white 22:14 < matches> And the flood fill is just "If it isn't white, stop" 22:14 < matches> Maybe I should set the background to have 0 alpha or something 22:15 < matches> Alpha seems to not actually do anything at the moment 22:27 < matches> http://szmoore.net/ipdf/who-the-hell-needs-antialiasing-anyway.png 22:44 < matches> http://szmoore.net/ipdf/shady-the-fox.png 22:47 < matches> rabbit_simple.svg actually doesn't work as well as rabbit.svg 22:48 < matches> I think one of the fill points of the outer ear is inside the inner ear 22:54 < sulix> Oh my... They're beautiful! 23:07 < matches> Ah crap 23:07 < matches> I will be pushing 23:07 < matches> 8 hours in the future 23:07 < matches> I really should fix my system clock 23:07 < matches> One of these days...