Color buffer compression

摘要

In accordance with some embodiments, a mask or table may be maintained to record information about whether or not each pixel within a tile is cleared. As used herein, a “cleared” tile is one that is not covered by any other depicted objects. The clear mask may store a bit per pixel or sample to indicate whether the pixel or sample contains a color value or whether it is cleared. As a result, the compression ratio may be increased for partially covered tiles in some embodiments.

主权项

1. A computer executed method comprising:
using two mode bits to indicate one of whether a tile has a constant alpha value, a constant alpha value of one or that the tile's alpha value varies across the tile; and based on whether a tile of pixels or samples has a constant or varying alpha value, determining how to store the tile.