Hi,
Felix recently suggested a change to SET_ALPHA_PIXEL_RGB32 in
DirectFB/src/gfx/generic/generic.h) that resulted in a nice
performance improvement and that we are now using. I tried to
do the same optimization to SET_ALPHA_PIXEL_RGB16 today and
here's what I have come up with:
#define SET_ALPHA_PIXEL_RGB16(d,r,g,b,a) \
if (a) {\
if (a == 0xFF) {\
*(d) = (((r)&0xf8) << 8) | (((g)&0xfc) << 3) | (((b)&0xf8) >> 3);\
}\
else {\
__u32 pixel;\
__u8 s=((a)>>2)+1;\
__u8 s1=(64-s);\
\
pixel = *(d);\
pixel = (((((pixel & 0x0000f81f) * s1) + ((((r)<<8) | ((b)>>3)) * s)) &
0x003e07c0) + \
((((pixel & 0x000007e0) * s1) + (((g)<<3) * s)) &
0x0001f800)) >> 6; \
*(d) = pixel;\
}\
}
This code is indeed faster (>15%), but the output is not perfect
(red bits seem to pollute the blue bits somehow). I have stared at
this code for too long and can't find what I'm doing wrong here.
Perhaps someone out there has an idea?
Salut, Sven
--
Info: To unsubscribe send a mail to [EMAIL PROTECTED] with
"unsubscribe directfb-dev" as subject.
