Abstract: A system and product for a DMA controller with multi-dimensional line-walking functionality is presented. A processor includes an intelligent DMA controller, which loads a line description that corresponds to a shape or line. The intelligent DMA controller moves through a memory map and retrieves data based upon the line description that includes a major step and a minor step. In turn, the intelligent DMA controller retrieves data from the shared memory without assistance from its corresponding processor. In one embodiment, the intelligent DMA controller may analyze a line using the rate of change along its minor axes in conjunction with locations where the line intersects subspaces and store array spans of contiguous memory along the line's major axis.

Abstract: A sampling module for adaptively sampling static data sets is provided. Two or more rays are cast onto a surface from a single point of origin. The ray or rays intersect the surface at various locations. The distance between the intersection points of each pair of adjacent rays is calculated. This distance is the current sample density. The current sample density is compared to the desired sample density. If the current sample density is not equal to the desired sample density then the sample density of the next casting of rays is adjusted accordingly.

Abstract: A system and method for cache optimized data formatting is presented. A processor generates images by calculating a plurality of image point values using height data, color data, and normal data. Normal data is computed for a particular image point using pixel data adjacent to the image point. The computed normalized data, along with corresponding height data and color data, are included in a limited space data stream and sent to a processor to generate an image. The normalized data may be computed using adjacent pixel data at any time prior to inserting the normalized data in the limited space data stream.

Abstract: A system and method for adaptive span computation when ray casting is presented. A processor uses start point fractional values during view screen segment computations that start a view screen segment's computations a particular distance away from a down point. This prevents an excessive sampling density during image generation without wasting processor resources. The processor identifies a start point fractional value for each view screen segment based upon each view screen segment's identifier, and computes a view screen segment start point for each view screen segment using the start point fractional value. View screen segment start points are “tiered” and are a particular distance away from the down point. This stops the view screen segments from converging to a point of severe over sampling while, at the same time, providing a pseudo-uniform sampling density.

Abstract: A system and method for generating an image that includes ray traced pixel data and rasterized pixel data is presented. A synergistic processing unit (SPU) uses a rendering algorithm to generate ray traced data for objects that require high-quality image rendering. The ray traced data is fragmented, whereby each fragment includes a ray traced pixel depth value and a ray traced pixel color value. A rasterizer compares ray traced pixel depth values to corresponding rasterized pixel depth values, and overwrites ray traced pixel data with rasterized pixel data when the corresponding rasterized fragment is “closer” to a viewing point, which results in composite data. A display subsystem uses the resultant composite data to generate an image on a user's display.

Abstract: A preferred embodiment of the present invention provides a method, computer program product, and processor design for supporting high-precision floating-point function estimates are split in two instructions each: a low precision table lookup instruction and a linear interpolation instruction. Estimates of different functions can be implemented using this scheme: A separate table-lookup instruction is provided for each different function, while only a single interpolation instruction is needed, since the single interpolation instruction can perform the interpolation step for any of the functions to be estimated. Thus, a preferred embodiment of the present invention incurs significantly less overhead than would specialized hardware, while still maintaining a uniform FPU latency, which allows for much simpler control logic.

Abstract: A system and method for optimized specular highlight generation is presented. A single microprocessor instruction is used to generate an intensity value based upon a viewing angle value. An application stores a viewing angle value in an input register. When called, the “intensity instruction” retrieves the viewing angle value from the input register, and calculates an intensity value using three distinct steps. In turn, the intensity instruction stores the intensity value in an output register for the application to retrieve and further process. In one embodiment, the invention may be implemented using PowerPC™ assembly and VMX™ or Altivec™ instructions. In this embodiment, the intensity instruction may be represented as a “vspecefp” instruction, which stands for a “vector specular estimate floating point” instruction.

Abstract: A system and method for a DMA controller with multi-dimensional line-walking functionality is presented. A processor includes an intelligent DMA controller, which loads a line description that corresponds to a shape or line. The intelligent DMA controller moves through a memory map and retrieves data based upon the line description that includes a major step and a minor step. In turn, the intelligent DMA controller retrieves data from the shared memory without assistance from its corresponding processor. In one embodiment, the intelligent DMA controller may analyze a line using the rate of change along its minor axes in conjunction with locations where the line intersects subspaces and store array spans of contiguous memory along the line's major axis.

Abstract: A system and method for terrain rendering using a limited memory footprint is presented. A vertical ray intersects a terrain data map at an angle which includes a minor step size. Weighting factors are assigned to triangular data sampling values and quadrilateral data sampling values based upon a vertical ray's minor step size. As a vertical ray's minor step size increases, a triangular data sampling's weighting factor increases and a quadrilateral data sampling's weighting factor decreases. Weighted triangular data sampling values and weighted quadrilateral data sampling values are combined to generate a vertical ray image point value.

Abstract: A system and method for terrain rendering using a limited memory footprint is presented. A system and method to perform vertical ray terrain rendering by using a terrain data subset for image point value calculations. Terrain data is segmented into terrain data subsets whereby the terrain data subsets are processed in parallel. A bottom view ray intersects the terrain data to provide a memory footprint starting point. In addition, environmental visibility settings provide a memory footprint ending point. The memory footprint starting point, the memory footprint ending point, and vertical ray adjacent data points define a terrain data subset that corresponds to a particular vertical ray. The terrain data subset includes height and color information which are used for vertical ray coherence terrain rendering.

Abstract: A system and method for cache optimized data formatting is presented. A processor generates images by calculating a plurality of image point values using height data, color data, and normal data. Normal data is computed for a particular image point using pixel data adjacent to the image point. The computed normalized data, along with corresponding height data and color data, are included in a limited space data stream and sent to a processor to generate an image. The normalized data may be computed using adjacent pixel data at any time prior to inserting the normalized data in the limited space data stream.

Abstract: The present invention provides for implementing a base two logarithmic estimation function in a general purpose processor. The present invention provides for partitioning an input value into a biased exponent value and a mantissa. Whether the biased exponent value is negative is determined. A first intermediate value from the mantissa is generated using custom combinational logic. A second intermediate value from the mantissa is generated using custom combinational logic. An unnormalized result fraction value from the first and second intermediate value and the mantissa is generated using custom combinational logic. This unnormalized result fraction and the unbiased exponent of the input are concatenated and normalized to form the final result.