Merged r4992:4993 from branches/SDL-1.2: increased alpha blend accuracy.
authorRyan C. Gordon <icculus@icculus.org>
Sun, 10 Jan 2010 06:18:39 +0000
changeset 3625 83910f4c373f
parent 3624 9b1af1049f66
child 3626 596468a8459e
Merged r4992:4993 from branches/SDL-1.2: increased alpha blend accuracy.
src/video/SDL_blit.h
--- a/src/video/SDL_blit.h	Sun Jan 10 05:39:46 2010 +0000
+++ b/src/video/SDL_blit.h	Sun Jan 10 06:18:39 2010 +0000
@@ -444,9 +444,9 @@
 /* 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)