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<Gmpint> 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 <path> 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...
+--- Day changed Mon Sep 01 2014
+17:05 < matches> The wobbly lines on things are irritating me
+17:10 < matches> There doesn't seem to be anything wrong with Bresenham, which means the actual line endpoints are wrong
+17:11 < matches> The GPU does everything from floats and magically they go to the right spot in the buffer
+17:11 < matches> The CPU has to calculate integer pixel coordinates
+17:16 < matches> I need a magnifier I can't see the pixels that are in the wrong spot
+17:16 < matches> I know they are there
+17:21 < matches> ... ok maybe the Bresen Ham was a little past its use by date
+19:48 < matches> The more I try and get these lines to not look dumb, the more convinced I become that glDrawLines is doing something fancy
+19:56 < matches> You end up with wiggles in the line because the end points round to a different pixel to what you end up at by drawing the line
+19:57 < matches> If you make sure you start from where the last line ended, you still get a bend because of the left over error from the last line
+19:58 < matches> ...
+19:58 < matches> Drawing a single line when you know the Bezier is actually a single line is probably going to be less rage inducing than trying to fix this
+21:01 < matches> The Beziers are now classified according to Loop and Blinn
+21:01 < matches> Well
+21:01 < matches> Maybe
+21:01 < matches> It at least knows what lines are
+21:01 < matches> ...
+21:02 < matches> Ok all the ttf beziers are SERPENTINE and LOOP so that's probably wrong
+21:43 < matches> Ah, floating point precision strikes again
+21:43 < matches> That's kind of annoying
+21:47 < matches> But I suppose it's relevant
+21:47 < matches> Unless I'm totally screwing something up
+21:48 * matches adds in arbitrary fabs(x) < 1e-6 checks
+21:58 < matches> On the other hand, if you use DeCasteljau and stop the sub dividing whenever you get to something that classifies as a line, it's actually pretty cool
+21:59 < matches> But if you zoom in too far it starts to get classifications totally wrong
+22:02 < matches> Yeah I have an abstract due in 2 weeks
+22:02 < matches> so screwed
+--- Day changed Tue Sep 02 2014
+13:42 < matches> Ok, let's not use floating point values for colours
+13:42 < matches> Baad
+13:43 < matches> Bad bad
+13:43 < matches> Bad sheep
+13:43 < matches> The project isn't about precision of representable colours
+13:44 < matches> So I'm perfectly OK with using uint8 for colour components
+18:53 < matches> Is it too late to change the aim of the project to "render svg-tests/fox.svg but without antialiasing"
+18:54 < matches> "Or using the GPU"
+18:55 < matches> Well, I understand why shading doesn't usually use flood fill now anyway
+18:55 < matches> But I still kind of think flood fill is better at high resolutions
+18:56 < matches> Not parallelisable I guess
+18:56 < matches> ... Or is it
+18:57 < matches> I was going to try and do arbitrary precision stuff but it seems we can no longer compile unless Real == double or float
+--- Day changed Wed Sep 03 2014
+17:26 < matches> It would seem Mr Munroe has beaten us...
+17:28 < matches> In Javascript
+17:28 < matches> We should die of shame
+17:29 < matches> Hahaha
+17:29 < matches> "// there is no elegance here. only sleep deprivation and regret"
+17:31 < matches> On the bright side, we now have a reason to reference xkcd
+17:31 < matches> I guess?
+17:59 < sulix> I just saw that, and had planned to use that comment as my next commit message.
+--- Day changed Thu Sep 04 2014
+10:59 * sulix sulix also engages panic mode.
+11:00 * sulix apparently also needs to engage sleep mode.
+11:00 * sulix almost engaged sheep mode by mistake.
+11:49 < sulix> How sure are you that SolveCubic works?
+18:37 < matches> Well, sure within 1e-4
+19:40 < matches> Rational<Gmpint> compiles again
+19:41 < matches> It just takes... several minutes... to load "The quick brown fox jumps over the lazy dog"
+21:04 < matches> I have a new ingenius plan
+21:06 < matches> This will probably not work but hopefully it won't take me too long...
+21:06 < matches> Oh dear what am I saying
+21:06 < matches> It's going to take a month now
+22:24 < matches> I really should be integrating one of those two libraries Rowan suggested into the project
+22:24 < matches> As opposed to implementing what I like to call the "Paranoid Number"
+22:25 < matches> It starts as a float
+22:25 < matches> It checks each operation for an exception, and if it does it adds the operation to a linked list instead
+22:25 < matches> After trying to simplify the next elements in the list
+22:26 < matches> This is going to be awful
+22:26 < matches> But it's been a while since I wrote a good linked list
+22:32 < matches> ... I think the last linked list I wrote had a nasty tendency to randomly segfault...
+22:32 < matches> Nevertheless we shall forge ahead
+23:14 < matches> You know you haven't had enough sleep when you start to terminate lines with ':' instead of ';'
+23:14 < matches> I blame python
+23:14 < matches> Not that it was valid python syntax either
+23:15 < matches> But it's a good scapesnake
+23:42 < matches> Oh recursive list based functions
+23:42 < matches> How I have missed you
+23:42 < matches> void Foo() {if (m_next != NULL) m_next->Foo();}
+23:42 < matches> <3
+--- Day changed Fri Sep 05 2014
+09:26 < matches> It sort of kind of works
+09:26 < matches> Except when it breaks
+09:26 < matches> ParanoidNumber::Simplify needs improvement
+09:26 < matches> Also operator+=
+09:26 < matches> operator-=
+09:26 < matches> operator*=
+09:26 < matches> and operator/=
+09:26 < matches> But it's definitely a number
+09:27 < matches> It just occasionally does things in totally the wrong order'
+09:28 < matches> So basically the idea is if you have an inexact (or overflow/underflow) operation, you delay it, and then in theory you can rearrange the operations so you have a smaller error...
+09:28 < matches> It seems to give better results than floats for tests/paranoidcalculator
+09:29 < matches> But that might be because it is initialised off 3/10 and the float starts at 0.3
+09:30 < matches> It could all be totally useless
+09:30 < matches> It probably is totally useless
+09:31 < matches> I have a hunch that even if it's terrible it might beat true arbitrary precision arithmetic
+09:31 < matches> In terms of actually being able to use it
+09:31 < matches> Who needs mathematics when you have blind intuition...
+--- Day changed Sun Sep 07 2014
+11:37 < sulix> Explicit mentions of hitting floating point precision issues in the xkcd comic: http://chromakode.com/post/notes-on-xkcd-pixels
+17:33 < unmercifulfish> mwahahaha
+17:34 < unmercifulfish> you can't escape my stalkerish tendencies now
+--- Day changed Mon Sep 08 2014
+11:10 < matches> This channel seemed like such a good idea at the time...
+11:19 < sulix> (So did the quadtree...)
+12:08 < Pommers> http://chromakode.com/post/notes-on-xkcd-pixels
+12:10 < sulix> It's gettign crowded in here.
+12:10 < sulix> Pommers: We were looking at that yesterday. The XKCD guys had it easy.
+12:11 < Pommers> Lets get all the people in here
+12:42 < unmercifulfish> IPDF PARTY
+13:49 < matches> Hmm, maths is harder than I thought
+15:41 < Pommers> Speaking of math, I know a guy who is looking for people versed in maths and willing to work on psuedo random number sets
+--- Day changed Wed Sep 10 2014
+11:50 < matches> So, compiling with mpfr reals is not as simple as including the mpfr real header and doing a typedef
+11:50 < matches> As there appear to be compiler errors in mpfr
+11:51 < matches> Does anyone actually check that things compile before including them in debian..
+11:53 < matches> I'd expect this sort of thing from Fedora
+11:58 < matches> Never mind it's namespace issues
+11:58 < matches> I'm sorry debian
+12:15 < matches> Something is horrendously broken about mpfrc++
+12:16 < matches> Oh
+12:17 < matches> #if REAL >= REAL_RATIONAL was not a wise choice
+12:21 < sulix> Ah...
+12:24 < matches> mpfrc++ is at least as precise as doubles but slower
+12:24 < matches> I never actually found the limit for doubles
+12:24 < matches> I should do that first
+12:26 < matches> Hmm, things start to disappear at around 4e-11 but you can still add stuff and it looks fine
+12:27 < matches> Ok doubles go crazy at 1e-17
+12:27 < matches> 1e-15 even
+12:30 < sulix> Is that zooming in on the origin, or somewhere further away?
+12:31 < matches> Somewhere further away
+12:31 < matches> If you translate towards the origin you can actually see the shapes start to get better
+12:31 < matches> It's actually pretty cool
+12:35 < matches> There's something dodgy with starting the View with low width/height as opposed to zooming in to the same width/height
+12:37 < matches> mpreal doesn't seem to want to show anything
+12:39 < matches> I think it's well past time we automated the zooming/translating process
+12:39 < matches> Sitting here zooming for 20 minutes is not really an effective use of time...
+12:47 < matches> Speaking of which, the CPU shading evaluates the fill points lazilly now, so you don't have to wait 5 minutes even with doubles just to load an SVG
+15:39 < sulix> For all of the hangers on... quadtrees are now slightly more functional.
+15:39 < Pommers> "functional"
+18:40 < iceweaselOS> Apparently talking in ICC isn't allowed
+18:41 < iceweaselOS> ICC
+18:41 < iceweaselOS> dammit
+18:41 < iceweaselOS> it has autocorrect
+18:42 < iceweaselOS> Humphrey the rabbit does not work :(
+18:42 < iceweaselOS> it gets stuck in pause
+--- Day changed Thu Sep 11 2014
+10:53 < matches> I wonder who that was
+10:59 < matches> "... for some reason in irram they decided to let x<y loop forever if x=y ..."
+10:59 < matches> That's...
+10:59 < matches> Ok
+10:59 < matches> Fine
+11:00 < matches> sulix: How many "x < y" checks do we have?
+11:10 < sulix> A finite number..., I guess?
+11:10 < matches> iRRAM appears to do some sort of fancy wrapping of MPFR
+11:11 < matches> So I'm not hopeful
+11:11 < matches> Considering MPFR seems to slow down hideously
+11:11 < sulix> Wrap all of the numbers inside other numbers.
+11:11 < matches> I did some more ParanoidNumber stuff
+11:11 < matches> Maybe one day it will actually give the correct result
+11:11 < matches> Then I can actually implement Simplify() ...
+11:12 < sulix> http://en.wikipedia.org/wiki/Binary_GCD_algorithm
+11:12 < sulix> (If you want fast gcd for bigints, btw)
+11:14 < matches> Should I plead "I had assignments due" or "I was seeing if Humphrey The Rabbit would work on a Firefox OS phone" in the progress meeting...
+11:14 < matches> iRRAM does seem to have a friendly install script
+11:15 < sulix> As long as you don't plead the FITH, you're probably fine. :P
+11:16 < matches> I'm fairly certain that floats are the best possible number representation and you need to do something more clever than just change your number representation if you want an arbitrary precision document
+11:16 < matches> Something like... some kind of... quad... tree
+11:17 < sulix> Do not use those words. You may not be able to vanquish what you summon.
+11:23 < matches> I need to write an abstract...
+11:24 < matches> "We compare different number representations and find them all to be useless"
+11:24 < matches> Hmm, something non commital
+11:25 < matches> "By the date of this conference we will hopefully have something interesting to say"
+11:25 < matches> "We discuss the drawbacks of adding IRC channel logs to git repositories"
+11:26 < matches> Ah nooo
+11:26 < matches> iRRAM uses "REAL"
+11:28 < matches> Also someone's been using too much javascript because there are all these extra ';' in their headers and it annoys -Werror=pedantic
+11:58 < sulix> ... :-(
+15:04 < matches> Spot the slight mathematical flaw in iRRAM
+15:04 < matches> inline LAZY_BOOLEAN operator == (const REAL& x, const REAL& y){ return (y<x)&&(x<y) ; }
+15:05 < matches> inline LAZY_BOOLEAN operator != (const REAL& x, const REAL& y){ return (y<x)||(x<y) ;}
+15:06 < matches> inline LAZY_BOOLEAN operator <= (const REAL& x, const REAL& y){ return (x<y); }
+15:06 < matches> They don't seem to have equality
+15:06 < matches> But that doesn't stop them implementing the operators...
+18:21 < sulix> Clearly the way to fix your computer's clock issues: http://jackf.net/bezier-clock/
+18:22 < matches> Against all better judgement I am still trying to fix ParanoidNumber
+18:22 < matches> And oh my goodness that is amazing
+18:23 < matches> But
+18:23 < matches> It still thinks it's 02:23:31
+18:23 < sulix> Unless I fix the quadtree view code, infinite precision only works if the coordinate you're zooming in on can _not_ be represented as a float.
+18:24 < matches> ?
+18:24 < matches> ??
+18:25 < sulix> So if you zoom in on a coordinate that is exactly representable as a sum of powers of two, then you're always zooming in on the boundary between two quadtree nodes.
+18:25 < matches> Haha
+18:26 < matches> Could you use an extra "centre" node?
+18:26 < matches> That would be redundant though
+18:26 < matches> Hm
+18:26 < sulix> Nah, I just need to actually get around to supporting displaying content from more than one node at a time.
+18:32 < matches> ParanoidNumbers seem to actually construct properly now
+18:32 < matches> At least, if you construct them and convert back to doubles, they are within 5% of the double
+18:33 < matches> Now... simplifying...
+18:33 < sulix> With float ParanoidNumbers or double ParanoidNumbers?
+18:33 < matches> doubles
+18:33 < matches> But I'm testing the traversal of the list(s) when converting back
+18:34 < sulix> Ahhh...
+18:34 < matches> You need two recursive functions and I really hope I don't get stack overflows...
+18:35 < matches> You start with "value = Head.value * Head.MultiplyFactors + Head.AddTerms"
+18:35 < matches> Then define MultiplyFactors as "1 * f1.AddTerms * f2.AddTerms * ..."
+18:36 < matches> Then AddTerms is "0 + t1.MultiplyFactors + t2.MultiplyFactors + ..."
+18:36 < matches> It gets confusing how you deal with division and subtraction...
+18:37 < matches> I'm sure you can write that as a non recursive function... somehow...
+18:37 < matches> I don't seem to be overflowing the stack though
+18:38 < matches> So 666 operations have taken 5 minutes
+18:38 < matches> But that's without simplifying anything
+18:38 * sulix is currently traversing quadtree nodes via needlessly complicated recusion.
+18:38 < matches> I am quitely confident that I may be able to render a frame in at most 10 years
+18:39 < sulix> Clearly in your seminar, you should start zooming in and when it gets slow just say "If you'll bear with me for a moment" and then just leave the room.
+18:39 < matches> The thought has crossed my mind...
+18:41 < matches> Something that is kind of cool is I can change the digit to be something like uint8_t and see how well it converts to floats
+18:41 < sulix> That is pretty cool.
+18:41 < matches> It will be when I implement it that is
+18:41 < sulix> How well _does_ it convert to floats?
+18:42 < sulix> (Also, sudden thought: is NaN a valid mark for this project, as I am getting the feeling it should be...)
+18:42 < matches> My paranoid number tester does occasionally fail with "NaN != NaN"
+18:42 < matches> That's good!
+18:42 < matches> They both got NaN!
+18:43 < matches> Well, ideally I will be able to make it so that the ParanoidNumber *doesn't* get NaN
+19:17 < sulix> Hmm... I think the ext4 driver just crashed on my computer.
+19:18 < matches> :S
+19:18 < sulix> I didn't know that was possible.
+19:25 * sulix -> other computer
+19:31 < matches> I'm inventing cool terminology
+19:31 < matches> Paranoia
+19:31 < matches> Is the number of ParanoidNumbers...
+19:33 < sulix> "Peeking around corners looking for NaNs, wearing a tinfoil hat to guard against surious SIGFPEs, it's... ParanoidNumber!"
+19:33 < matches> That is the best description
+19:33 < matches> Well
+19:34 < matches> It actually kind of blindly walks around the corner into the SIGFPE and then freaks out and runs back around it
+19:35 < sulix> It's like running away from the fireball in slow motion.
+19:37 < matches> I'll at least win an award for most original number representation
+19:37 < matches> (He hopes)
+19:37 < matches> (It's probably not)
+19:38 < matches> (It's probably equivelant to one of the many alternative number representations that I didn't look up...)
+19:38 * sulix also hopes there is an award for most buggy implemention of a quadtree.
+19:38 < matches> (Specifically, the ones in the Handbook of Floating Point arithmetic that were described as "curiously useless")
+19:40 < sulix> (Googling "curiously useless" yields the phrase: "My boss is curiously useless. He fanatically creates an abundant amount of work for everyone while at the same time manages to get nothing done.")
+19:40 < sulix> (I suspect they're referring to iRRAM)
+19:40 < matches> Bahaha
+19:43 < matches> I think that simply replacing floats with int8_t actually does work
+19:44 < matches> Which is cool because it is easier to test if an operation with int8_t can be represented exactly
+19:44 < matches> But on the other hand there will be fewer operations that can be represented exactly
+19:45 < matches> I think this may actually work
+19:46 < matches> You don't need arbitrary precision to represent screen space and you are converting from view space to screen space
+19:47 < matches> So maybe it won't be that terrible, even though it would need a lot more digits to represent the same arbitrary precision value
+19:47 < matches> I think
+19:47 < sulix> You need more than an int8_t to represent screen space.
+19:47 < sulix> (An int16_t would do it, though)
+19:48 < matches> You just need to be able to represent each individual factor in the operation
+19:48 < matches> factor and term
+19:48 < sulix> You may (probably will) need factors > 127
+19:48 < matches> Probably
+19:50 < matches> If I just implement an "Exact" template function...
+19:50 < matches> Uh oh, templates
+19:51 * sulix thinks that he's approaching the worst recursive subroutine ever written.
+19:52 < sulix> (It has four switch statements in it so far)
+19:57 < matches> Template errors
+19:57 < matches> Aargahasdf
+19:58 < matches> Compilers are so good at identifying exactly what error you made and so useless at actually providing any hint of how you can fix it
+19:58 < matches> It's totally different from like "expected ';' before ..."
+19:59 < sulix> I saw a feature request for Google translate to support "gcc -> English".
+19:59 < matches> I want to specialise some template static member functions...
+19:59 < matches> That was my first mistake...
+20:00 < matches> Ok, they don't need to be static member functions, they can just be ... whatever you call a function that has no namespace associated with it
+20:01 < sulix> Functions...?
+20:01 < matches> Bah
+20:01 < matches> I would say "Regular functions" but they tend to be less common in C++
+20:02 < sulix> I've heard them called "first-class functions" before.
+20:03 < matches> That's a little elitist
+20:03 < sulix> I'm sort-of enamoured with the idea of "business-class functions" and "economy-class functions," though.
+20:11 < sulix> BTW, I just commited something that doesn't compile. Fixes will come shortly, it was just the easiest way to get it from computer A -> computer B.
+20:13 * sulix has made a typo and copy-pasted it into 16 places.
+20:13 < matches> copy-paste is best practice...
+20:14 < matches> It irks me that "a -= b" is equivelant to "a += (-b)" but there is no "a /= b == a *= (-b)"
+20:14 < matches> Well there is sort of, but only for rationals
+20:14 < sulix> The operator you're looking for is (1 / b)
+20:14 < matches> Yes, but - is quicker
+20:14 < sulix> This is true.
+20:15 < matches> I mean 3 can be represented exactly but 1/3 cannot
+20:15 < matches> With floats
+20:15 < matches> Most annoying
+20:15 < matches> I'm currently trying to reduce all the superflous "{0 + ...}" in ParanoidNumber
+20:16 < matches> It likes to create 1000 element lists with 900 zeroes in a row
+20:35 < unmercifulfish> this is gripping reading
+20:35 < unmercifulfish> so glad I am a part of this
+20:35 < matches> This is the cutting edge of useless research
+20:41 < sulix> "The bézier tiptoed out of bed. What an adventure it would be to go beyond the quadtree node in which it had lived its entire life. Its mother had told it sternly that it was dangerous to wander the dark wastes beyond the root node. Bobby Bézier had never believed the stories, though: there were no such things as wild NaNs that ate all of the coefficients of naughty boys. Bobby looked up at the sky: the infinite void of night penetrated only by the deb
+20:43 < Pommers> Oh yeah. One of the people in cs has a nice post on their door about rabbits that I want to grab a copy of
+20:50 < matches> I have a "TrustingOp" and "ParanoidOp"
+20:50 < matches> I think I'm having too much fun...
+20:54 * sulix has decided to give up actually coding and take up writing bézier curve fanfiction full time.
+20:55 < sulix> (People say it's derivative, but it's just about to reach a turning point)
+21:15 < unmercifulfish> qdb
+23:09 < matches> Oh dear
+23:09 * matches curses kahan
+23:10 < matches> I do not understand how this works, but if I delete terms that are "-0" things break
+23:13 < matches> So I got to the point where ParanoidNumber gave results that were reasonably close to just using a normal double without simplifying them
+23:14 < matches> And now I am basically adding random lines of code and running the tester and seeing if it still works :S
+--- Day changed Fri Sep 12 2014
+00:15 < matches> This reminds me of the James Micken comment about addition and multiplication basically being the same thing...
git.ucc.asn.au / ipdf / documents.git / blobdiff
UCC git Repository :: git.ucc.asn.au