Automatic commit of irc logs

So you're back... about time...

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 23:34 <@matches> I'm pretty sure it just means we need a better tester
 23:38 <@matches> Or
 23:38 <@matches> We lie
+--- Day changed Wed Sep 24 2014
+12:33 <@matches> Ok, sulix do you want to help design these comparisons that we were going to use
+12:35 <@matches> We've got the "qualitative" comparisons pretty well...
+12:36 <@matches> It's the other 4 things
+12:36 <@matches> Performance vs number of primitives
+12:36 <@matches> Like
+12:36 <@matches> Do we add N primitives randomly?
+12:36 <@matches> Are our "test" documents just going to be Humphrey The Rabbit and Shady the Fox
+12:36 <@matches> Not that I have any objection to using them
+12:36 < sulix> I think so.
+12:36 <@matches> I'll add Emma the Cat and Mitch the Panda
+12:37 < sulix> Number of primitives should just be number of curves/objects.
+12:37 < sulix> I could do with some panda-monium. :P
+12:37 <@matches> Pommers beat you to that one
+12:37 <@matches> That's the name of the club's panda
+12:38 <@matches> I don't think I'll add Sam the Girraffe
+12:38 <@matches> It's embarrassing
+12:38 <@matches> Oh also did you read the wall of text?
+12:39 <@matches> Because I think we need a new way to demonstrate how much better the quad tree is than regular floats other than just zooming forever
+12:39 <@matches> Regular floats do quite well now
+12:39 <@matches> I should probably commit this
+12:39 < sulix> What about adding objects?
+12:39 <@matches> I also tried to get it to run without X for bus purposes
+12:39 <@matches> Well
+12:40 <@matches> Basically I threw out the idea of the view and just applied the transforms directly to all the object bounds
+12:40 <@matches> It will still print the equivelant view coordinates
+12:40 < sulix> Can you zoom out and then back in again?
+12:41 <@matches> I suspect if you go far enough there will be issues
+12:41 <@matches> The problem is going far enough takes a long time
+12:41 <@matches> We need to make ipdf take input so we can automate it?
+12:41  * sulix will do that this afternoon.
+12:41 <@matches> Or implement a "tester" that does it
+12:42 <@matches> HFP has a chapter on reducing error which boils down to rearranging the operands
+12:43 <@matches> Although they don't have anything as insanely dumb as ParanoidNumber
+12:43 < sulix> Isn't that what ParanoidNumber does?
+12:43 <@matches> Yeah
+12:43 <@matches> But ParanoidNumber doesn't assume any knowledge over what you are trying to do
+12:43 <@matches> Hence it is horribly inefficient
+12:44 < sulix> I suspect we need to sit down with Kahan and work out what the exact mathematical properties of floating-point error.
+12:44 <@matches> Their examples are like "If you know you are going to sum all these numbers, you sort them"
+12:44 <@matches> HFP goes through them
+12:45 <@matches> Sometimes you can represent the error as another float but with twice the precision?
+12:45 <@matches> It might be worth looking at whether MPFR includes the "Inexact" exception
+12:45 <@matches> Then you could just double the precision every time it occured?
+12:46  * sulix will be back shortly.
+12:47 <@matches> It's going to be a fun study break :S
+12:54 <@matches> Also PN manages to pass realops but somehow give totally whack behaviour when you actually use it
+12:54 <@matches> ...
+12:54 <@matches> And this is enforcing a size limit of "0" (which means it should just be equivelant to doubles!)
+12:55 <@matches> Also I should probably also write a draft thesis
+12:55 <@matches> Also other units suck, why can't the project count as 4 units
+12:56 <@matches> I'm finally starting to understand this properly, as we are running out of time at an alarming rate
+12:56 <@matches> I guess there probably won't be any experts on floating point arithmetic at my conference so I can probably pretend I know things
+13:02 <@matches> http://szmoore.net/ipdf/i-think-there-might-be-a-slight-maths-error-rabbit.png
+13:03 <@matches> I strongly suspect Copy/Paste errors
+14:07 < Pommers> Yeah. We have a club Panda
+14:10 -!- matches changed the topic of #ipdf to: IPDF: Infinite Panda Document Format
+14:13 <@matches> Um
+14:13 <@matches> cat.svg causes a segfault
+14:23 <@matches> It has an empty path?
+14:23 <@matches> I regret somewhat making the path be from m_start to m_end *inclusive*
+14:37 <@matches> Have a git push
+14:37 <@matches> Possibly with a correct timestamp
+14:47 <@matches> Ok, things still go whack when you apply transforms to objects instead of the view
+14:48 <@matches> But because you can add objects in screen space rather than converting to view space and back, you don't get the precision issues adding a new object
+14:48 <@matches> I suspect
+14:48 <@matches> If you add a new object at say 1e-6
+14:48 <@matches> It looks fine
+14:49 <@matches> Then you zoom back out to 0.5,0.5,1,1 or something
+14:49 <@matches> Then zoom back in
+14:49 <@matches> It *should* look all wierd again
+14:49 <@matches> Then again it might not
+14:49 <@matches> Because floating point errors are crazy
+14:51 <@matches> It does!
+14:51 <@matches> YES
+14:52 <@matches> It looks totally screwed up in a different way
+14:52 <@matches> So, I guess this just makes it more important that you can actually add elements to the quad tree
+14:53  * sulix feels the pressure mounting.
+14:54 <@matches> Is the quad tree kind of equivelant to applying the transformations to the objects but making sure you don't lose the original bounds
+14:54 <@matches> When you zoom back out you get the original bounds back
+14:54 < sulix> Yeah, largely.
+14:54 <@matches> Cool
+14:54 <@matches> I'm sure someone trained in maths can say smart stuff about that
+14:55 <@matches> Applying transformations to the object bounds is probably the best way if you have an arbitrary precision number representation
+14:55 <@matches> You can use a lower precision representation when you work in screen space then
+14:55 <@matches> Although I'm not sure how I would actually implement that...
+14:56 <@matches> With some kind of
+14:56 <@matches> Quad tree...
+14:56 <@matches> maybe
+14:56 <@matches> I guess if two methods end up with the same pixels in the same spot then they are mathematically equivelant
+14:58 <@matches> You could also speed things up
+14:58 <@matches> If you exploited the Path bounds
+14:58 <@matches> Express all the beziers within a path relative to {0,0,1,1} then just apply your transformation to the path
+14:58 < sulix> This is a much better design.
+14:59 <@matches> Well that's sort of a compromise between transforming the view or transforming all the bounds
+14:59 < sulix> But it's sort-of too late to change it all now.
+14:59 <@matches> I think I might have to though
+14:59 <@matches> If I want to make GMPrat performant
+15:00 <@matches> Lets face it, I'm doing a better job at redesigning the document structure to be less terrible than I am at actually implementing arbitrary precision number types :S
+15:01 <@matches> I could probably redesign the CPU renderer, but the GPU renderer would be harder
+15:01 <@matches> PathRenderer already does everything BezierRenderer does, but it adds shading
+15:02 <@matches> I think right now I will try to stop PN from being quite so broken
+15:02 <@matches> I am perplexed
+15:03 <@matches> As there is basically an "assert(equivelant to double)" after every single operation
+15:03 <@matches> None of them fail
+15:03 <@matches> And it gives a totally wrong result
+15:45 <@matches> It is rendering at 666 FPS
+15:46 <@matches> :O
+16:49 <@matches> Ok
+16:49 <@matches> There should be postive paranoid numbers soon
+16:49 <@matches> s/postive/negative
+16:49 <@matches> That thing that happens when you put a '-' sign in front of a number
+16:49 <@matches> Very important
+16:50 < sulix> Negative _and_ paranoid? I'm waiting for the "Number Theropy" classes next... :P
+16:50 <@matches> I've learned some valuable lessons about implementing number classes I guess
+16:50 < sulix> At least it isn't complex?
+16:50 <@matches> Make sure you test every single function against doubles
+16:51 <@matches> (Including constructors)
+16:51 <@matches> I'm really over bug fixing this class
+16:51 <@matches> I just want to make it faster dammit
+16:51 <@matches> I have ideas about how to make it faster
+16:53 <@matches> Admittedly they are mostly not good ideas
+16:53 <@matches> I'm expecting the arena may help more when I don't enforce a size limit of zero though
+16:54 <@matches> YES
+16:54 <@matches> I can render a paranoid rabbit
+16:54 <@matches> Oh wait
+16:54 <@matches> I didn't increase the size limit from zero
+16:54 <@matches> That will be the real test...
+17:02 <@matches> So are you going to implement a magical automated zoomer? :P
+17:03 <@matches> We kind of need to be able to choose what point to zoom in on depending on the particular test svg though :S
+17:04 <@matches> Right now it's hard to tell whether I am getting precision issues or I just accidentally moved the mouse a bit
+21:02 < sulix> That's about the most terrifying email it's possible to get, I think.
+21:59 < sulix> Very simple scripts for automating actions now exist.