Abstract: A scalar processor that includes a plurality of scalar arithmetic logic units and a special function unit. Each scalar unit performs, in a different time interval, the same operation on a different data item, where each different time interval is one of a plurality of successive, adjacent time intervals. Each unit provides an output data item in the time interval in which the unit performs the operation and provides a processed data item in the last of the successive, adjacent time intervals. The special function unit provides a special function computation for the output data item of a selected one of the scalar units, in the time interval in which the selected scalar unit performs the operation, so as to avoid a conflict in use among the scalar units. A vector processing unit includes an input data buffer, the scalar processor, and an output orthogonal converter.

Abstract: A method and apparatus for obtaining an attribute in homogenous space. After obtaining the vertices of a triangle, the world space coordinates and the attribute of each vertex are transformed to homogeneous coordinates and an attribute in viewer space. Then a set of homogenous coefficients of the triangle is computed based on the viewer space vertex homogeneous coordinates, and the viewer space coordinates of each vertex are projected to coordinates in screen space. Pixels in the screen space that are affected by the projected triangle are determined. For each pixel affected by the triangle, a set of barycentric coefficients in viewer space is computed, based on the homogenous triangle coefficients, and a linear interpolation is performed based on the set of viewer space barycentric coefficients and the viewer space attributes of the triangle vertices to obtain the attribute of the pixel affected by the triangle.

Abstract: A faster algorithm for computing the texture of a pixel is disclosed. A major and minor direction in texel space are determined. Steps in the major direction are set to unity and steps in the minor direction are set to the slope of the anistropy line of the footprint. The end points of the anistropy line in the major direction are then positioned to be on grid in the texture space. The texture is computed for each sample along the anistropy line by computing an interpolation cooefficient for the sample, linearly interpolating two texels based on the cooefficient, weighting the interpolated sample, and accumulating the weighted samples. The result is the texture value to be used for the pixel.

Abstract: A system for executing instructions is presented. In some embodiments, among others, the system comprises functional units, local multiplexers, local register files, and a global register file, which are communicatively coupled to each other and arranged to accommodate shortened instruction words in multiple-issue processors. These components are arranged to permit greater access to registers by instructions, thereby permitting reduction of the word length, as compared to conventional very long instruction word (VLIW) processors.

Abstract: The computer graphics system is configured to generate a shadow effect with a stencil shadow volume method using a combination of compressed and uncompressed stencil buffers in coordination with compressed and uncompressed depth data buffers. An uncompressed stencil buffer is capable of storing stencil shadow volume data for each pixel and a compressed stencil buffer is capable of storing stencil shadow volume data for a group of pixels.

Abstract: The computer graphics system is configured to improve the performance of a stencil shadow volume method for rendering shadows. The apparatus and methods utilize a combination of compressed and uncompressed stencil buffers in coordination with compressed and uncompressed depth data buffers. An uncompressed stencil buffer is capable of storing stencil shadow volume data for each pixel and a compressed stencil buffer is capable of storing stencil shadow volume data for a group of pixels. The compressed stencil buffer is utilized with a compressed stencil buffer cache to perform a stencil shadow volume operation more efficiently than present methods.

Abstract: The computer graphics system is configured to generate a shadow effect with a stencil shadow volume method using a combination of compressed and uncompressed stencil buffers in coordination with compressed and uncompressed depth data buffers. An uncompressed stencil buffer is capable of storing stencil shadow volume data for each pixel and a compressed stencil buffer is capable of storing stencil shadow volume data for a group of pixels.

Abstract: A low-cost high-speed programmable rasterizer accepting an input set of functionals representing a triangle, clipping planes and a scissoring box, and producing multiple spans per clock cycle as output. A Loader converts the input set from a general form to a special case form accepted by a set of Edge Generators, the restricted input format accepted by the Edge Generators contributing to their efficient hardware implementation.

Abstract: One embodiment of the present invention is directed to a graphics system comprising logic for generating a mask that identifies bits within a plurality of bits that are not to be impacted by a subsequent computation. The graphics system further comprises compression logic that is responsive to the mask for generating a compressed bit stream, such that the bits that are not to be impacted by the computation are not included in the compressed bit stream. Another embodiment of the present invention is directed to a graphics system comprising logic for generating a mask identifying positions within a plurality of positions of a bit stream that are to be removed during a compression operation.

Abstract: One embodiment of the present invention is directed to a method for a computer graphics system comprising compressing a plurality of groups of bits by shifting compressed groups of bits into bit positions that are to be removed during the compression, the logic being responsive to a mask, wherein contents of the mask define variable amounts that the plurality of bits are shifted during the compression. Another embodiment is directed to a method for compressing a plurality of groups of bits to eliminate groups of bits that are to be unaffected by a computation, performing the computation, and thereafter decompressing corresponding data after performing the computation to restore data corresponding to previously eliminated groups of bits.

Abstract: An orthogonal data converter for converting the components of a sequential vector component flow to a parallel vector component flow. The data converter has an input rotator configured to rotate corresponding vector components of the sequential vector component flow by a prescribed amount, and a bank of register files configured to store the rotated vector components. The converter also has an output rotator configured to rotate the position of the vector components read from the bank of register files by a prescribed amount. A controller of the converter is operative to control the addressing of the bank of register files and the rotating of the vector components. In this regard, the controller is operative to write the vector components to the bank of register files in a prescribed order and read the vector components in a prescribed order to generate the parallel vector component flow.

Abstract: A method and apparatus for obtaining an attribute of a pixel in homogenous space. After obtaining the vertices of a triangle, the world space coordinates and the attribute of each vertex are transformed to coordinates and an attribute in viewer space. Then a set of homogenous coefficients of each vertex is computed based on the viewer space coordinates, and the viewer space coordinates of each vertex are projected to coordinates in screen space. Pixels in the screen space that are affected by the triangle are determined based on the screen space coordinates. For each pixel affected by the triangle, a set of barycentric coefficients in homogenous space is computed, based on the homogenous coefficients, and a linear interpolation is performed based on the set of homogenous barycentric coefficients and the attributes of the vertices in the viewer space to obtain the attribute in the homogenous space of that pixel.