METHOD AND GRAPHICS PROCESSING SYSTEM FOR RENDERING ONE OR MORE FRAGMENTS HAVING SHADER-DEPENDENT PROPERTIES

A graphics processing unit and method for processing fragments in a graphics processing system which includes: (i) hidden surface removal logic configured to perform hidden surface removal on fragments, and (ii) processing logic configured to execute shader programs for fragments. Initial processing of fragments is performed at the hidden surface removal logic. Some of the fragments have a shader-dependent property. A shader program for a particular fragment having the shader-dependent property is split into two stages. The initial processing comprises performing a depth test on the particular fragment. In response to the particular fragment passing the depth test of the initial processing in the hidden surface removal logic, a first stage, but not a second stage, of the shader program is executed for the particular fragment at the processing logic. The first stage of the shader program has instructions for determining the property of the particular fragment.