gdk_draw_* and friends

[Deborah Swayne <dfs research att com>]

I've been interested all discussion about plural gdk_draw
routines, since I'm used to using those in X, and I do a <lot> of
drawing -- scatterplots of up to 100,000 points, which may be in
motion.  I was delighted to be convinced that they don't improve
performance, because it simplifies my code to get rid of them.

However, I've just learned that the plural routines improve
performance **twenty-fold** for Windows versions of gtk
programs.  I can take advantage of this information to improve
the drawing speed for points and line segments, but I'm in
trouble when it comes to polygons and arcs.  (I do my work on
*nix, but I do want the results to run under Windows.)

Given what I'm learning about the Windows API, the most useful
routine would be gdk_draw_polygons.  Windows draws rectangles as
polygons anyway, and they have no plural routine for drawing
arcs.  (They use a routine called PolyPolygon for drawing
multiple polygons.)

I don't know whether the gtk authors take Windows portability
issues into consideration when making gtk/gdk design choices.
That can lead to weird deformations in gtk design, but it can
also make gtk much more powerful as a toolkit for writing
portable code.  For me, it is a significant competitor to Java
even now.

Debby

-- 
Deborah Swayne               AT&T Labs - Research 
dfs@research.att.com         Shannon Laboratory, Room B295     
www.research.att.com/~dfs    180 Park Avenue
973 360-8423                 Florham Park, NJ 07932-0971