Intel Corporation
Use of inner coverage information by a conservative rasterization pipeline to enable EarlyZ for conservative rasterization

Abstract:

Embodiments described herein are generally directed to conservative rasterization pipeline configurations that allow EarlyZ to be enabled for conservative rasterization. An embodiment of a method includes receiving, by a conservative rasterizer, a primitive; creating, by the conservative rasterizer, a pixel location stream based on the primitive and inner coverage data for each pixel within the pixel location stream indicative of whether the corresponding pixel is fully covered or partially covered by the primitive; for each block of pixels of the pixel location stream, launching, by the conservative rasterizer, a thread of a pixel shader, including causing EarlyZ to be performed or not for fully covered pixels and partially covered pixels, respectively; and generating, by the pixel shader, a stream of pixel updates by conditionally processing the pixel location stream to incorporate pixel shading characteristics, including for partially covered pixels computing a depth value and causing LateZ to be performed.