Abstract: A data processing system providing high performance three-dimensional graphics includes at least one system processor, chipset core logic, a graphics processor, and a Z-buffer. In one embodiment an adaptive hierarchical visibility (AHV) method performs occlusion-culling in a tiled 3D graphics hardware architecture. Polygon bins for each tile are bucket-sorted in order of increasing depth Z. Polygon bins are rendered starting with the bin closest to the viewer. After some number of bins are rendered, a single layer, hierarchical Z-buffer (HZ) may be constructed from the Z-buffer thus far accumulated for the rendered bins, if it would be cost effective to do so. Subsequent bins are rendered by first testing their polygons against the HZ buffer to see if they are hidden. Also described are an integrated circuit for implementing the AHV algorithm, and a computer-readable medium storing a data structure for implementing the AHV method and apparatus.

Abstract: A computer graphics system for caching textures includes an L3 memory, an L2 cache, and an L1 cache for storing such textures and also includes a graphics accelerator (GA) for mapping these stored textures onto primitives for graphics display. The L3 memory, which has the largest capacity also has the slowest retrieval speed, while the L1 cache has the smallest capacity and the quickest retrieval speed. The textures are divided into a plurality of L2 texture blocks and each L2 texture block is subdivided into a plurality of L1 sub-blocks. During its rendering process, the GA searches the L1 cache for a particular L1 sub-block that is to be applied to a primitive. If such L1 sub-block is stored within the L1 cache, the GA will extract the desired texels (i.e., texture pixels) from the L1 sub-block and apply such texels to the primitive. If the L1 sub-block is not located in the L1 cache, the GA will search the L2 cache for the L1 sub-block.

Abstract: An adaptive forward differencing apparatus wherein, when rendering curves, calculated x, y values are increased or decreased in order to create values which correspond to the next pixel of the display CRT, such that curves of substantially one pixel increments are continuously and uniformly generated. The apparatus also provides circuitry for generating coordinates of display elements which approximate an ideal vector and to define curves, vectors or objects within maximum and minimum coordinates of the CRT display. The present invention also provides efficient circuitry for computing the value of 1/w of the homogenous coordinate w.

Abstract: The present invention provides unique methods and apparatus for shading curves, polygons and patches, implementing Phong, Gouraud and other shading techniques in the rendering of images on a cathode ray tube or other display device. The present invention also includes a unique method and apparatus for shading patches by rendering a series of adjacent curves such that no pixel gaps exist between each rendered curve.

Abstract: An adaptive forward differencing apparatus wherein, when rendering curves, calculated x, y values are increased or decreased in order to create values which correspond to the next pixel of the display CRT, such that curves of substantially one pixel increments are continuously and uniformly generated. The apparatus of the present invention also provides circuitry for generating coordinates of display elements which approximate an ideal vector and to define curves, vectors or objects within maximum and minimum coordinates of the CRT display. The present invention also provides efficient circuitry for computing the value of 1/w of the homogenous coordinate w.