STENCIL THEN COVER PATH RENDERING WITH SHARED EDGES

摘要

One embodiment of the present invention includes techniques for rasterizing primitives that include edges shared between paths. For each edge, a rasterizer unit selects and applies a sample rule from multiple sample rules. If the edge is shared, then the selected sample rule causes each group of coverage samples associated with a single color sample to be considered as either fully inside or fully outside the edge. Consequently, conflation artifacts caused when the number of coverage samples per pixel exceeds the number of color samples per pixel may be reduced. In prior-art techniques, reducing such conflation artifacts typically involves increasing the number of color samples per pixel to equal the number of coverage samples per pixel. Advantageously, the disclosed techniques enable rendering using algorithms that reduce the ratio of color to coverage samples, thereby decreasing memory consumption and memory bandwidth use, without causing conflation artifacts associated with shared edges.

主权项

1. A computer-implemented method for rasterizing geometric primitives, the method comprising:
determining a rasterization state associated with a plurality of geometric primitives; selecting a first sample rule from a plurality of sample rules based on the rasterization state, wherein the first sample rule determines coverage of a plurality of coverage samples based on the position of a first coverage sample included in the plurality of samples; determining whether the first coverage sample is considered to be inside a first edge of a first geometric primitive included in the plurality of geometric primitives based on the first sample rule; and determining whether the first coverage sample is considered to be covered by the first geometric primitive based on whether the first coverage sample is considered to be inside the first edge.