[Mesa-dev] gl_FragCoord / FBOs vs mesa/st

[Dave Airlie]

Eric just checked in a test into piglit that tests that the
gl_FragCoord works the right way up for FBOs,

Now all the gallium drivers fail this currently and fixing it creates
an ugly linkage between the currently bound buffer and the fragment
shader, since if you swap from an FBO to rendering to the front
buffer, you need recompile the fragment shader to emit a proper wpos
manipulation. Just wondering if anyone sees a nicer way to do this,
than caching frag shaders with some sort of key in the state tracker,
(which is pretty much what 965 has done.).

Dave.