Mesa Adds Compute Shader Decoding For ASTC

The Mesa 23.1 graphics driver code has added support for software-based decoding of Adaptive Scalable Texture Compression (ASTC) textures via compute shaders.

For hardware without native Adaptive Scalable Texture Compression (ASTC) support, the Mesa state tracker for Gallium3D has implemented compute shader based decoding that will work across hardware.

This is similar to Mesa's recent addition of compute based transcoding for DXT5. The ASTC compute shader implementation is based on the code from the Granite Vulkan renderer by Hans-Kristian Arntzen.

Intel dropped ASTC hardware support in Gen12.5 graphics hardware and newer. Adaptive Scalable Texture Compression was originally devised by AMD and Arm while has been supported by The Khronos Group for OpenGL and OpenGL ES for the past decade. While surprising Intel had removed it from Gen12.5 graphics hardware, at least there is this new compute shader based implementation.

See this merge request that landed in Mesa 23.1 today for all the details on this compute shader based decoding for ASTC.