tree 0acfd8a710993cd2dd19ad099cd9de51ca9a3bf0
parent cd67427e271f6fa631b35af1aa1b4afa35852cb4
author Sam Lantinga <slouken@libsdl.org> 1475343970 -0700
committer Sam Lantinga <slouken@libsdl.org> 1475343970 -0700

Fixed bug 3368 - SDL_Blit_Slow doesn't ignore alpha values in colorkey comparison

Simon Hug

When the SDL_Blit_Slow function compares the pixel to the color key it does so without removing the alpha component from the pixel value and the key. This is different from the optimized 32-bit blitters which create a rgb mask and apply it to both to filter the alpha out. SDL_Blit_Slow will only skip the pixels with the exact alpha value of the key instead of all pixels with the same color.

The attached test case blits a surface with a color key and prints the pixel values to the console. The third row is expected to be skipped.