Programmable blending via multiple pixel shader dispatches

A method for dispatching pixel information in a graphics processing pipeline, the method comprising:

• generating a first pixel comprising a plurality of samples based on a first portion of a graphics primitive received by a first thread;
• calculating a set of source values, wherein each source value corresponds to a different sample in the plurality of samples;
• retrieving a set of destination values from a render target, wherein each destination value corresponds to a different source value in the set of source values;
• blending each source value with a corresponding destination value to create a set of final values;
• determining that a second thread is performing an operation on the first pixel;
• stalling the second thread until the first thread completes executing operations related to the first pixel;
• and
• releasing the second thread.

A subsystem comprising:

• a fragment processing unit configured to dispatch pixel information in a graphics processing pipeline by performing the steps of:
• generating a first pixel comprising a plurality of samples based on a first portion of a graphics primitive received by a first thread;
• calculating a set of source values, wherein each source value corresponds to a different sample in the plurality of samples;
• retrieving a set of destination values from a render target, wherein each destination value corresponds to a different source value in the set of source values;
• blending each source value with a corresponding destination value to create a set of final values;
• and
• creating two or more dispatch messages to store the set of final values in a set of output registers.

A computer-readable storage medium including instructions that, when executed by a processing unit, cause the processing unit to perform an operation for dispatching pixel information in a graphics processing pipeline, the operation comprising:

• generating a first pixel comprising a plurality of samples based on a first portion of a graphics primitive received by a first thread;
• calculating a set of source values, wherein each source value corresponds to a different sample in the plurality of samples;
• retrieving a set of destination values from a render target, wherein each destination value corresponds to a different source value in the set of source values;
• blending each source value with a corresponding destination value to create a set of final values;
• and
• creating two or more dispatch messages to store the set of final values in a set of output registers.