[Freeciv-Dev] Re: Render speed test with imlib/xrender/sdl/pixbuf/ftwl

[Jason Dorje Short <jdorje@xxxxxxxxxxxx>]

Raimar Falke wrote:

> Also note that I can only say that ftwl is used correctly. Please
> suggest any other improvements of the usage of the other libs.
Note that most (99%) of our graphics don't use alpha.  And with some 
tilesets (speciallly designed for older computers or for gui-xaw) no 
graphics use alpha.  For graphics without alpha drawing is much faster. 
 For instance with gdk2 I measure drawing with pixmap+mask to be 4x 
faster than drawing with pixbufs.  So the current method in the gtk2 
client uses pixmap+mask for all sprites that don't use alpha, and pixbuf 
for those that do.
This is a reason why cairo xlib drawing is slow also.  They use xrender 
even when there is just a 1-bit mask.  I consider this a bug in cairo 
(although because of cairo's design it is fixable, whereas with 
gdkpixbuf the problem is unfixable).  It's probably also a bug in 
xrender, which should try to use the fast drawing if possible.
Summary: use server-side drawing where possible, client-side drawing 
where necessary.  Design the interface so that this may happen 
transparently in the backend.
-jason