(svn r13721) -Codechange: one less multiplication for colour mixing in 32bpp blitters (GeekToo)
--- a/src/blitter/32bpp_base.hpp Thu Jul 17 21:15:57 2008 +0000
+++ b/src/blitter/32bpp_base.hpp Thu Jul 17 23:43:47 2008 +0000
@@ -54,9 +54,9 @@
/* The 256 is wrong, it should be 255, but 256 is much faster... */
return ComposeColour(0xFF,
- (r * a + cr * (256 - a)) / 256,
- (g * a + cg * (256 - a)) / 256,
- (b * a + cb * (256 - a)) / 256);
+ ((int)(r - cr) * a) / 256 + cr,
+ ((int)(g - cg) * a) / 256 + cg,
+ ((int)(b - cb) * a) / 256 + cb);
}
/**
@@ -79,15 +79,8 @@
uint r = GB(colour, 16, 8);
uint g = GB(colour, 8, 8);
uint b = GB(colour, 0, 8);
- uint cr = GB(current, 16, 8);
- uint cg = GB(current, 8, 8);
- uint cb = GB(current, 0, 8);
- /* The 256 is wrong, it should be 255, but 256 is much faster... */
- return ComposeColour(0xFF,
- (r * a + cr * (256 - a)) / 256,
- (g * a + cg * (256 - a)) / 256,
- (b * a + cb * (256 - a)) / 256);
+ return ComposeColourRGBANoCheck(r, g, b, a, current);
}
/**