Abstract: Method and apparatus for neighbor and edge indexing is described. A vertex is identified and assigned a reference. One-ring neighbor vertices of the vertex are identified. The reference is assigned to each of the one-ring neighbor vertices identified. An index to one of the one-ring neighbor vertices is assigned. The index is successively incremented to provide indices for each of the one-ring neighbor vertices remaining. Edge indexing follows as described above, with the vertex and its one-ring neighbors defining end points of edges. Additionally, offset indexing is described, and may be used for a consistent order of computation.

Abstract: Method and apparatus for generating a primitive extension defining a generalized primitive is described. The primitive extension defines the connectivity and vertices used to specify a collection of connected primitives, such as a strip-type or fan-type generalized primitive. A generalized primitive includes a number of vertices where some of the vertices are shared with neighboring primitives. The primitive extension includes an originating primitive, vertex data, and connectivity information. The primitive extension provides a general interface for describing a variety of connected primitives.

Abstract: A fixed function engine and method are described for processing a set of primitive commands. One embodiment of the fixed function engine includes a means for receiving one or more primitive commands, where each such primitive command includes information for processing vertex data using a user-developed program or subroutine. The fixed function engine also includes a means for determining a set of related primitive commands from the received primitive commands and a means for identifying a first primitive command to process from that set. In addition, the fixed function engine includes a means for transmitting a first program command, which is related to the first primitive command, to a processing engine for processing.

Abstract: A programmable geometry engine is described. One embodiment of the programmable geometry engine includes a programmable primitive engine configured to receive primitive commands that include information for processing vertex data using user-developed programs or subroutines. The programmable primitive engine also is configured to transmit program commands that include program pointers and data pointers. In addition, the programmable geometry engine includes a processing engine configured to receive the program commands. The processing engine is further configured to retrieve the user-developed programs or subroutines using the program pointers and to retrieve vertex data using the data pointers. Also, the processing engine is configured to process the vertex data based on instructions included in the user-developed programs or subroutines to produce processed vertex data and to transmit results to the programmable primitive engine.