diff options
| -rw-r--r-- | graphics/transparent_surface.cpp | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/graphics/transparent_surface.cpp b/graphics/transparent_surface.cpp index 02611aa60f..b4d73d1078 100644 --- a/graphics/transparent_surface.cpp +++ b/graphics/transparent_surface.cpp @@ -177,14 +177,17 @@ void doBlitAlphaBlend(byte *ino, byte *outo, uint32 width, uint32 height, uint32 for (uint32 j = 0; j < width; j++) { uint32 ina = in[kAIndex] * ca >> 8; - out[kAIndex] = 255; - out[kBIndex] = (out[kBIndex] * (255 - ina) >> 8); - out[kGIndex] = (out[kGIndex] * (255 - ina) >> 8); - out[kRIndex] = (out[kRIndex] * (255 - ina) >> 8); - out[kBIndex] = out[kBIndex] + (in[kBIndex] * ina * cb >> 16); - out[kGIndex] = out[kGIndex] + (in[kGIndex] * ina * cg >> 16); - out[kRIndex] = out[kRIndex] + (in[kRIndex] * ina * cr >> 16); + if (ina != 0) { + out[kAIndex] = 255; + out[kBIndex] = (out[kBIndex] * (255 - ina) >> 8); + out[kGIndex] = (out[kGIndex] * (255 - ina) >> 8); + out[kRIndex] = (out[kRIndex] * (255 - ina) >> 8); + + out[kBIndex] = out[kBIndex] + (in[kBIndex] * ina * cb >> 16); + out[kGIndex] = out[kGIndex] + (in[kGIndex] * ina * cg >> 16); + out[kRIndex] = out[kRIndex] + (in[kRIndex] * ina * cr >> 16); + } in += inStep; out += 4; |