Abstract: The VPC unit and setup unit of a graphics processing subsystem perform culling operations. The VPC unit performs culling operations on geometric primitives falling within a specific criteria, such as having a property within a numerical range limit of the VPC unit. This limitation reduces the complexity of the VPC unit. As increasing rendering complexity typically produces a large number of small primitives, the VPC unit can cull many primitives despite its culling limitations. The VPC unit also includes a cache for storing previously processed vertices in their transformed form, along with culling information previously computed for the vertices. To minimize memory bandwidth, the VPC unit retrieves vertex data used for culling operations first. After completing the culling operations, the VPC unit retrieves the attributes of a vertex only if the primitive has not been culled. The VPC unit applies a perspective correction factor to the vertex attributes.

Abstract: Accordingly, embodiments of the present invention provide circuits, methods, and apparatus that improve utilization of storage buffers by overwriting data in them as soon as the data is no longer needed. An exemplary embodiment employs a counter to add each time a particular unit of data is needed by a circuit. The counter also subtracts each time the data is actually used by the circuit. When the counter reaches zero, upstream circuitry is checked to see if a command allowing the particular data to be overwritten has been issued. If it has, the command is not waited for, rather the data may be overwritten immediately. Embodiments of the present invention may also make use of one level of indirection to mask physical storage buffer locations from upstream circuitry. In this way, utilization can be improved.

Abstract: A system, method and computer program product are provided for programmable pixel processing in a computer graphics pipeline. In one embodiment of the present invention, a computed arbitrary quantity is applied as texture address.

Abstract: A texture procedure allows the rendering of curve bounded objects to a graphics display device directly from a high level curve-based description. The method comprises receiving a curve-based description of the graphics object and dividing the graphics object into a rectangular mesh of texels. Each texel is then detailed by defining a combination of curved geometry functions and a boolean function. These function are then evaluated for each pixel of the graphics display device thereby rendering the graphics object to a graphics display. The texture procedure features include being procedural based and not image-based. This allows a rendering with continued accuracy even under arbitrary magnification conditions. Furthermore, the texture procedure is defined as such that will allow it to function using conventional tri-linear interpolation hardware.