Tile-based immediate mode rendering with early hierarchical-z

A graphics pipeline apparatus, comprising:

• a vertex shader;
• a visibility shader communicatively coupled to an output of the vertex shader, wherein the visibility shader is to construct a hierarchical visibility structure that is to identify one or more primitives as being occluded, wherein the visibility shader is to identify if a group of pixels are occluded, if the group of pixels are not occluded the visibility shader is to subdivide the group of pixels into smaller groups and conduct individual determinations of whether the smaller groups are each occluded to construct the hierarchical visibility structure, and if the group of pixels are occluded the visibility shader is to determine that the group of pixels are occluded without a subdivision of the group of pixels to construct the hierarchical visibility structure;
• a tile renderer communicatively coupled to an output of the vertex shader and to the visibility shader, wherein the tile renderer is to:
• identify from the hierarchical visibility structure generated by the visibility shader that the one or more primitives are occluded, and
• perform a tile-based immediate mode render on the output of the vertex shader to cull the one or more primitives based on the one or more primitives being identified as being occluded in the hierarchical visibility structure;
• and
• a rasterizer communicatively coupled to an output of the tile renderer, wherein the rasterizer is to:
• identify from the hierarchical visibility structure generated by the visibility shader that the one or more primitives are occluded, and
• rasterize the output of the tile renderer to avoid rasterization of the one or more primitives based on the one or more primitives being identified as being occluded in the hierarchical visibility structure.

A method of rasterizing, comprising:

• constructing a hierarchical visibility structure that is to identify one or more primitives as being occluded;
• identifying from the hierarchical visibility structure that the one or more primitives are occluded;
• performing a tile-based immediate mode render on an output of a vertex shader to cull the one or more primitives based on the one or more primitives being identified as being occluded in the hierarchical visibility structure;
• rasterizing the output of the tile-based immediate mode render to avoid rasterization of the one or more primitives based on the one or more primitives being identified as being occluded in the hierarchical visibility structure;
• identifying if a group of pixels are occluded;
• if the group of pixels are not occluded, subdividing the group of pixels into smaller groups and conducting individual determinations of whether the smaller groups are each occluded to construct the hierarchical visibility structure;
• and
• if the group of pixels are occluded, determine that the group of pixels are occluded without a subdivision of the group of pixels to construct the hierarchical visibility structure.

At least one non-transitory computer readable storage medium, comprising a set of instructions, which when executed by a computing device cause the computing device to:

• construct a hierarchical visibility structure that is to identify one or more primitives as being occluded;
• identify from the hierarchical visibility structure that the one or more primitives are occluded;
• perform a tile-based immediate mode render on an output of a vertex shader to cull the one or more primitives based on the one or more primitives being identified as being occluded in the hierarchical visibility structure;
• rasterize the output of the tile-based immediate mode render to avoid rasterization of the one or more primitives based on the one or more primitives being identified as being occluded in the hierarchical visibility structure;
• identify if a group of pixels are occluded;
• if the group of pixels are not occluded, subdivide the group of pixels into smaller groups and conduct individual determinations of whether the smaller groups are each occluded to construct the hierarchical visibility structure;
• and
• if the group of pixels are occluded, determine that the group of pixels are occluded without a subdivision of the group of pixels to construct the hierarchical visibility structure.