Merged r4992:4993 from branches/SDL-1.2: increased alpha blend accuracy.

This commit is contained in:
Ryan C. Gordon 2010-01-10 06:18:39 +00:00
parent d3fddfb2b4
commit 23a7f67e85

View File

@ -444,9 +444,9 @@ do { \
/* Blend the RGB values of two Pixels based on a source alpha value */
#define ALPHA_BLEND(sR, sG, sB, A, dR, dG, dB) \
do { \
dR = ((((int)(sR-dR)*(int)A)/255)+dR); \
dG = ((((int)(sG-dG)*(int)A)/255)+dG); \
dB = ((((int)(sB-dB)*(int)A)/255)+dB); \
dR = (((((int)(sR-dR)*((int)A))+255)/255)+dR); \
dG = (((((int)(sG-dG)*((int)A))+255)/255)+dG); \
dB = (((((int)(sB-dB)*((int)A))+255)/255)+dB); \
} while(0)