http://bugs.winehq.org/show_bug.cgi?id=14045
--- Comment #12 from Alexander Sabourenkov screwdriver@lxnt.info 2008-08-15 00:45:25 --- (In reply to comment #11)
We haven't had apps that required software rendering. Sketchup used to work but I'm not sure when it stopped working. Perhaps it was after we unleashed all the pixel formats (we used to have only 1 due to some x11drv limitations). Try a regression test.
It must be some generic fall back, there must also be some format which it really wants to have. I doubt it wants to use software rendering.
Without HW_OK=1 it really wants a format with PFD_GENERIC_FORMAT | ^PFD_GENERIC_ACCELERATED, I confirmed this by hacking up DescribePixelFormat and friends to return predefined flag combinations, and testing.
I don't see what can be done here. I don't think GLX can be forced to render in software for a given app only. Maybe duplicate all pixel formats as second copy having PFD_GENERIC_FORMAT | ^PFD_GENERIC_ACCELERATED. Or maybe return one pixel format with those flags and error out when it gets selected.