Programmable blending via multiple pixel shader dispatches

Abstract

Techniques are disclosed for dispatching pixel information in a graphics processing pipeline. A fragment processing unit in the graphics processing pipeline generates a pixel that includes multiple samples based on a portion of a graphics primitive received by a thread. The fragment processing unit calculates a set of source values, where each source value corresponds to a different sample of the pixel. The fragment processing unit retrieves a set of destination values from a render target, where each destination value corresponds to a different source value. The fragment processing unit blends each source value with a corresponding destination value to create a set of final values, and creates one or more dispatch messages to store the set of final values in a set of output registers. One advantage of the disclosed techniques is that pixel shader programs perform per-sample operations with increased efficiency.