EXT_shader_samples_identical Lands In Mesa

Ian Romanick has landed support for the GL_EXT_shader_samples_identical extension within Mesa. This is a new OpenGL extension worked on by this member of Intel's Open-Source Technology Center team.

GL_EXT_shader_samples_identical isn't yet part of the official OpenGL registry, but the Mesa documentation explains it as a way for reducing bandwidth use when reading multi-sample textures where the values in the multi-sample control surface are all the same. Besides Ian Romanick working on this extension, Chris Forbes has also been working on it and others at Intel along with Graham Sellers at AMD.

More background and other information on it can be found via Ian's blog. It will also be relevant if supporting SPIR-V for Vulkan and OpenCL in the future. For Mesa 11.1, only Intel Gen7 graphics and newer will support this extension to varying degrees.