Re: [matplotlib-devel] contourf masking bug

[John H. <jd...@gm...>]

On 7/12/07, Carl Worth <cw...@cw...> wrote:

> What's the "GTK drawing model" here that is problematic? Is that
> pre-cairo stuff? And can using cairo directly help at all?

Yes, this is pre cairo and unfortunately, no I don't think cairo can
help.  When I wrote MPL, it was GTK only and I used GDK for rendering.
 The backend canvas was a gtk.DrawingArea calls and the renderer was a
gdk.Drawable which defined methods like draw_rectangle and
draw_polygon

  http://www.pygtk.org/pygtk2reference/class-gdkdrawable.html

As I added other backends, backend_ps first, I abstracted the
gtk.DrawingArea, gdk.Drawable and gdk.GC to the FigureCanvas, Renderer
and GraphicsContext respectively which are are core backend base
classes, and then for each backend did a concrete implemention of the
gdk.Drawable API, etc.    This was back in 2001.  If I were smarter or
had done more research at the time, I would have chosen a different
drawing mode, eg DisplayPDF or something like that, but I guess I was
too busy coding ....  (reminds me of a joke we used to tell in the lab
"Why spend and hour in the library when you can get the same result in
the lab in a year?").

So the fact that GTK now uses Cairo doesn't help us too much, since
all of our backends implement the gdk.Drawable API more or less.  What
we are discussing here is a clean room reimplementation of our backend
API and drawing model.

JDH