http://bugs.winehq.org/show_bug.cgi?id=8426
------- Additional Comments From stefandoesinger@gmx.at 2007-21-05 18:31 ------- One more thing that came to my mind: If you set up the gl format as format = GL_BGRA and type = GL_UNSIGNED_SHORT_5_5_5_1_REV, then you can skip the masking and shifting altogether and just set the highest bit (1 << 15) to 1 or 0. You'll have to set it to 0 explicitly ( *Dest &= ~(1 << 15) ) if the color key applies to remove junk that is possibly set in this bit.