US Patent 9978171 Control of a sample mask from a fragment shader program

A method, system, and computer program product for controlling a sample mask from a fragment shader are disclosed. The method includes the steps of generating a fragment for each pixel that is covered, at least in part, by a primitive and determining coverage information for each fragment corresponding to the primitive. Then, for each fragment, the method includes the steps of generating a sample mask by a fragment shader, replacing the coverage information for the fragment with the sample mask, and writing, based on the sample mask, a result generated by the fragment shader to a memory. The method may be implemented on a parallel processing unit configured to implement, at least in part, a graphics processing pipeline.