THIS IS A WORK IN PROGRESS
Mesa is building a big shader when using ARB_texture_env_combine. The
idea is to bypass that computation, do it ourselves and cache the
compiled program in a CoglMaterial.
For now that feature can be enabled by setting the COGL_PIPELINE
environment variable to "arbfp". COGL_SHOW_FP_SOURCE can be set to a non
empty string to dump the fragment program source too.
TODO:
* fog (really easy, using OPTION)
* support tex env combiner operands, DOT3, ADD_SIGNED, INTERPOLATE
combine modes (need refactoring the generation of temporary
variables) (not too hard)
* alpha testing for GLES 2.0?
9815d75ebd