Compression Using Index Bits in MSAA

摘要

A palette compressed representation may be stored in the index bits, when that is possible. The savings are considerable in some embodiments. In uncompressed mode, the data uses 2304 (2048+256) bits, and in compressed mode, the data uses 1280 bits. However, with this technique, the data only uses the index bits, (e.g. 256 bits) with a 5:1 compression improvement over the already compressed representation, and with respect to the uncompressed representation it is a 9:1 compression ratio.

主权项

1. A method comprising:
attempting to compress cache lines using a color palette; checking whether the palette compression meets a bit budget; and if so, storing an indicator in a control surface that palette compressor was used, storing the compressed representation in index bits in a color buffer and marking the cache lines as evicted.