XBC7 planning

I've been doing this for fun as a side project, as ASTC is still way more important. (ASTC is the most deployed GPU format in the world, BC7 is niche by comparison.) It'll all be entirely open source: - XBC7 v1 (completed, integrating ongoing): Always lossless for mode config+RGBA endpoints, lossless or lossy weights using either lossless residual DPCM or lossy absolute or residual DCT. DPCM…