The 06-circle-alpha.png picture has the same color everywhere, so all of it
gets colorkeyed out. I think it's more fair to compare speeds when the
results
look more or less the same with alpha or color key, and with realistic
sprites.
Here are results with three sprites from one of my games. The cloud sprite
has
very few completely transparent or completely solid pixels, while the other
two
sprites have anti-aliased edges. Note that the cloud looks like complete
crap
with colorkey blitting.
Conclusions:
* Anti aliased edges are pretty cheap (0.09 vs 0.10, 0.5 vs 0.7)
* RLEACCEL is a big win on all of these sprites.
Table: Blit times, normalized to 1.0 for no optimization. The sprites
are pretty small. 10000 blit average, on an ibook g4 running linux.
balloon draco cloud
no optimization 1.00 1.00 1.00
convert only 0.15 0.13 0.07
colorkey no RLEACCEL 0.25 0.36 0.40
colorkey with RLEACCEL 0.09 0.05 0.06
convert_alpha only 0.14 0.22 0.22
convert_alpha with RLEACCEL 0.10 0.07 0.15
Regards,
Ulf
