I don't think there's anything I can look into. I can't duplicate the
problem on my system, and Plot doesn't do anything platform-specific, so
the bug is almost certainly in `pict', `racket/draw' or Cairo. Matthew?
Sorry I wasn't clear on this earlier.
(It could be that it's *possible* duplicate it on my system, and that it
only shows up on the build machine because the default font is a
different size, which gives the plot areas slightly different sizes,
which gives the projected triangles slightly different vertices. I could
look into that, but it seems unlikely. I use Plot a *lot* and have never
seen this before.)
If I were debugging it, I'd try to find the simplest plot that's missing
a polygon. Here are the bad plots from the docs, rendered the way the
docs do it (plot to a pict, then convert to a bitmap), with the number
of samples easy to tweak:
#lang racket
(require pict plot/pict)
(plot3d-samples 41) ; default is 41
(parameterize ([plot-z-ticks (currency-ticks)])
(pict->bitmap
(plot3d-pict (contour-intervals3d (λ (x y) (- (sqr x) (sqr y)))
-1 1 -1 1
#:label "z")
#:legend-anchor 'center)))
(pict->bitmap
(plot3d-pict (polar3d (λ (θ ρ) 1)
#:color 2
#:line-style 'transparent)
#:altitude 25))
I'd also try passing #:out-file "out.pdf" to `plot3d-pict' to see if the
PDF back-end is afflicted.
I don't know how worried to be about missing polygons. It could be
anything from bad array management in Cairo (which could be serious) to
a mostly harmless problem in the implementation of region culling or
winding rules.
Neil ⊥
On 12/29/2013 09:39 PM, Robby Findler wrote:
Neil: have you had time to look into this? If not, then I think we
should just leave it for the next release. Please let us know what
you're thinking about this one.
Robby
On Sat, Dec 21, 2013 at 4:13 PM, Neil Toronto <neil.toro...@gmail.com
<mailto:neil.toro...@gmail.com>> wrote:
Some plots in the documentation are missing a polygon. I think it's
platform-specific, because I can't reproduce the problem.
Examples:
First example plot in "1.5 Renderer and Plot Bounds" (look for a
light green rectangle)
file:///usr/racket-5.91.0.900/__doc/plot/intro.html?q=plot#%__28part._.Renderer_and_.Plot_.__Bounds%29
Last example plot in `plot-z-far-ticks' docs (look for a white hole
under the "z" in the legend)
http://plt.eecs.northwestern.__edu/snapshots/current/doc/__plot/ticks_and_transforms.__html?q=plot-z-far-ticks#%__28def._%28%28lib._plot%2Fmain.__.rkt%29._plot-z-far-ticks%29%__29
<http://plt.eecs.northwestern.edu/snapshots/current/doc/plot/ticks_and_transforms.html?q=plot-z-far-ticks#%28def._%28%28lib._plot%2Fmain..rkt%29._plot-z-far-ticks%29%29>
Here's a program that renders one of the bad plots like Scribble
does (I think):
#lang racket
(require pict plot/pict)
(pict->bitmap
(plot3d-pict (polar3d (λ (θ ρ) 1) #:color 2 #:line-style 'transparent)
#:altitude 25))
Neil ⊥
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