Intel Skylake Adds ASTC Texture Compression, Open-Source Support Coming

S3TC remains the most common form of texture compression relied upon by video game developers and others, but it remains a legal mess for open-source graphics drivers. ETC2 texture compression isn't faced by legal issues but was only mandated by OpenGL ES 3.0 / OpenGL 4.3, which makes it less well adopted. Meanwhile, in looking forward to the future, ASTC is the royalty-free next-gen texture compression solution that's backed by the Khronos Group. Intel's forthcoming Skylake hardware will make ASTC a much more widespread reality.

ASTC is short for the Adaptive Scalable Texture Compression and is a lossy, block-based algorithm originally designed by ARM. ASTC has become an official extension for not only OpenGL and OpenGL ES but is also part of Microsoft's Direct3D 11.3/12. The graphics processors on the upcoming Intel Skylake processors will feature native support for ASTC.

With ASTC being royalty-free, Intel Open-Source Technology Center developers have been working to provide the support within the open-source Intel Mesa driver. That work has now materialized in the public spotlight in patch form on the Mesa-dev list.

Intel developer Nanley Chery is requesting comments on the ten new patches that enable support for 2D ASTC HDR and LDR formats and is enabled for Intel "Gen9" Skylake graphics. "This patch series adds support for the KHR_texture_compression_astc_{ldr,hdr} extensions. The last two commits enable support for Skylake systems. Some rendering issues were encountered during testing, so there is some more work to be done on this feature."

This KHR_texture_compression_astc_ldr and KHR_texture_compression_astc_hdr enablement only affects core Mesa and the Intel driver for Skylake and newer but doesn't touch the other drivers. There's still some issues with this Mesa ASTC code, but will hopefully all be ironed out in time for Mesa 10.7.