https://bugs.winehq.org/show_bug.cgi?id=39014
--- Comment #16 from Stefan Dösinger stefan@codeweavers.com --- Created attachment 52058 --> https://bugs.winehq.org/attachment.cgi?id=52058 Don't require an exact color key match
The O2Jam problem seems to be a precision issue. The game uses an R5G6B5 texture, and the color key is 31/20/31, which translates to r=1.0, g=20/63, b=1.0. The rounding of the green value is different between our color key calculation and the normalization during texture sampling, causing the key not to match.
The attached patch allows a small mismatch, which seems to fix the game. We need some tests for this though to make sure we're not matching keys we shouldn't match, and we need the same change in the ARB and GLSL fixed function fragment shader.