X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=irc%2F%23ipdf.log;h=b3caf873debee6f2ab67b2711ae29b044c416cbc;hb=658c156ba0465e3f42572275eb8f9702050293d6;hp=91c4f45332e78baa75096ace457c64b411124f55;hpb=c85bc148a76e98161a8aaed897150c1f415ee47d;p=ipdf%2Fdocuments.git

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--- a/irc/#ipdf.log
+++ b/irc/#ipdf.log
@@ -112,3 +112,420 @@
 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)
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+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
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+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
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+19:57 <@13VAAAAGJ> I'd edit the commit script to censor the swear words, but effort
+19:57 <@13VAAAAGJ> Oh dear
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+19:57 <@13VAAAAGJ> Hello
+19:58 <@13VAAAAGJ> I think mantis might be dying?
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+20:05 <@13VAAAAGJ> Sigh
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+--- 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]
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+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
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+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<float> View<double> 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