[Mesa-dev] [PATCH V2 00/22] Add ARB_texture_multisample support

[Chris Forbes]

This series adds the core mesa bits and i965 driver support for
ARB_texture_multisample.

Big changes from V1:
   - Generally cleaner
   - GLSL texelFetch() with a multisample sampler is converted to
      a new ir_txf_ms opcode in the GLSL IR, which makes the driver side
      a lot tidier.
   - Most of the review comments have been addressed.
   - Intel driver support includes both Gen6 and Gen7 now.
   - Lots of bugs fixed.

Remaining issues:
   - Stencil support is still a mess. This is disabled in the intel driver
     for now by exposing only GL_MAX_DEPTH_TEXTURE_SAMPLES=1. To do this
     properly requires some more small changes in core mesa to cope with
     stencil-only texture formats a bit better, and Intel-specific support
     to cope with the strange W-tiled stencil buffer format.

   - The IvyBridge support forces uncompressed multisample layout, which
     is wasteful of memory bandwidth. Allowing CMS here requires emitting
     specialized code based on the multisample layout, since fetching from
     an undefined MCS surface isn't safe.

   - It's unclear whether deallocating multisample textures via zero
     dimensions is legal, or whether the texture object must be deleted.

I'm going to continue working on these issues, but would appreciate another
round of review comments in the mean time.

-- Chris