Method and apparatus for culling in a graphics processor with deferred shading

A computer program product for use in conjunction with a computer system, the computer program product comprising a computer readable storage medium and a computer program mechanism embedded therein, the computer mechanism, comprising:

• a program module that directs the culling of graphics information comprising a plurality of graphics primitives, the program module including instructions for:
• sorting said graphics primitives into tiles, wherein said 2-dimensional screen is represented by said tiles;
• and wherein said culling is performed such that all graphics primitives sorted to a first tile are processed before graphics primitives sorted to a second tile;
• identifying a first group of primitives wherein each primitive overlaps a pixel of a two-dimensional display screen region;
• culling portions of said first group of primitives that do not affect a final color of said pixel, thereby generating a potentially visible group of graphics information wherein said graphics primitives comprise vertices and a time order of said vertices is preserved within each tile during said culling;
• and
• dispatching said potentially visible group of graphics information to a pixel unit.

A method for culling graphics primitives prior to rendering said graphics primitives in a two-dimensional region, said method comprising:

• sorting said graphics primitives into tiles, wherein said 2-dimensional screen is represented by said tiles;
• and wherein said culling is performed such that all graphics primitives sorted to a first tile are processed before graphics primitives sorted to a second tile;
• identifying a first group of graphics primitives, each of said first group of graphics primitive overlapping a pixel of a two-dimensional display region;
• culling portions of said first group of graphics primitives that do not affect a final value of said pixel wherein said graphics primitives comprise vertices and a time order of said vertices is preserved within each tile during said culling;
• generating a potentially visible group of graphics primitives that excludes said culled graphics primitive portions;
• and
• communicating at most selected ones of said potentially visible group of graphics primitives but none of said culled portions of said graphics primitives to a pixel rendering unit.

A method for culling in a graphics rendering pipeline configured to render three-dimensional (3-D) graphics information onto a two-dimensional (2-D) screen, said graphics information comprising a plurality of graphics primitives, said method comprising:

• sorting said graphics primitives into tiles, wherein said 2-dimensional screen is represented by said tiles;
• and wherein said culling is performed such that all graphics primitives sorted to a first tile are processed before graphics primitives sorted to a second tile;
• identifying a first group of primitives wherein each primitive overlaps a pixel of said 2-D screen;
• culling portions of said first group of primitives that do not affect a final color of said pixel, wherein said culling is performed such that guaranteed opaque geometry within said first tile is processed before other geometry in said first tile thereby generating a potentially visible group of graphics information;
• and
• dispatching said potentially visible group of graphics information to a pixel unit.

A method for culling graphics primitives prior to rendering said graphics primitives in a two-dimensional region, said method comprising:

• sorting said graphics primitives into tiles, wherein said 2-dimensional screen is represented by said tiles;
• and wherein said culling is performed such that graphics primitives sorted to a first tile are processed before graphics primitives sorted to a second tile;
• identifying a first group of graphics primitives, each of said first group of graphics primitive overlapping a pixel of a two-dimensional display region;
• culling portions of said first group of graphics primitives that do not affect a final value of said pixel wherein said culling is performed such that guaranteed opaque geometry within said first tile is processed before other geometry in said first tile;
• generating a potentially visible group of graphics primitives that excludes said culled graphics primitive portions;
• and
• communicating at most selected ones of said potentially visible group of graphics primitives but none of said culled portions of said graphics primitives to a pixel rendering unit.