Programmable tile shader

摘要

In accordance with some embodiments, a tile shader executes on a group of pixels prior to a pixel shader. The tile of pixels may be rectangular in some embodiments. The tile may be executed hierarchically, refining each tile into smaller subtiles until the pixel or sample level is reached. The tile shader program can be written to discard groups of pixels, thereby quickly removing areas of the bounding triangles that lie outside the shape being rasterized or quickly discarding groups of pixel shader executions that will not contribute to the final image.

主权项

1. A method comprising:
rasterizing a first group of tiles of a given size, in terms of number of pixels per tile; executing tile shading on each rasterized tile of said first group of tiles by programmatically computing output data for a tile or discarding the tile; if a tile is not discarded, sending said output data to a subsequent stage including a pixel shader in a graphics pipeline; and repeating said rasterizing and then a corresponding said tile shading by way of at least one tile shader, and executing on groups of tiles of progressively smaller size and terminating the repeated rasterizing and repeated tile shading and executing based on the result of executing, and when a smallest hierarchical level is reached, performing pixel shading for all pixels in that tile.