infernap12/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2026-04-08 05:58:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

6998323: Unexpected color change after invoking SplashScreen.update()

Browse Source 
Fix the blendRGB() function

Reviewed-by: art, dcherepanov
This commit is contained in:
Anthony Petrov 2010-12-22 17:37:34 +03:00
parent 92a7b61171
commit 2ee20ffcdb
1 changed files with 8 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
jdk/src/share/native/sun/awt/splashscreen/splashscreen_gfx_impl.h
View File

@ -88,27 +88,18 @@ ditherColor(rgbquad_t value, ImageFormat * format, int row, int col)
/* blend (lerp between) two rgb quads
src and dst alpha is ignored
the algorithm: src*alpha+dst*(1-alpha)=(src-dst)*alpha+dst, rb and g are done separately
it's possible to verify that it's almost accurate indeed */
*/
INLINE rgbquad_t
blendRGB(rgbquad_t dst, rgbquad_t src, rgbquad_t alpha)
{
const rgbquad_t dstrb = dst & 0xFF00FF;
const rgbquad_t dstg = dst & 0xFF00;
const rgbquad_t srcrb = src & 0xFF00FF;
const rgbquad_t srcg = src & 0xFF00;
const rgbquad_t a = alpha;
const rgbquad_t a1 = 0xFF - alpha;
rgbquad_t drb = srcrb - dstrb;
rgbquad_t dg = srcg - dstg;
alpha += 1;
drb *= alpha;
dg *= alpha;
drb >>= 8;
dg >>= 8;
return ((drb + dstrb) & 0xFF00FF) | ((dg + dstg) & 0xFF00);
return MAKE_QUAD(
(rgbquad_t)((QUAD_RED(src) * a + QUAD_RED(dst) * a1) / 0xFF),
(rgbquad_t)((QUAD_GREEN(src) * a + QUAD_GREEN(dst) * a1) / 0xFF),
(rgbquad_t)((QUAD_BLUE(src) * a + QUAD_BLUE(dst) * a1) / 0xFF),
0);
}
/* scales rgb quad by alpha. basically similar to what's above. src alpha is retained.