Sun Microsystems, Inc.

Ranjit S Oberoi

Michael G Lavelle

Michael Frank Deering

David C Kehlet

Michael Wasserman

Brian D Emberling

Nathaniel David Naegle

Ewa M Kubalska

Nandini Ramani

Yan Yan Tang

Anthony S Ramirez

Deron D Johnson

Wayne Eric Burk

Philip C Leung

Salvatore Arcuri

Te-Chun Yu

A graphics system invokes a dicing process if one or more edges of a triangle T have length greater than a maximum length (L), invokes a central subdivision process if a coverage estimate for the triangle T is greater than a maximum coverage and all edges of triangle T have length less than or equal to L, invokes rendering of a sequence of one or more single-layer triangles based on triangle T if the coverage estimate for triangle T is less than or equal to the maximum coverage and all edges have length less than or equal to L. Said invocation of rendering of the sequence of single-layer triangles results in the application of a plurality of texture layers to samples corresponding to triangle T. The samples are stored in the TAB between the application of successive layers of said plurality of texture layers.

Triangle coverage estimation and edge-correct tessellation

A system and method are disclosed for reproducing a pre-selected larger 2-D sample location pattern from a smaller one by means of X,Y address permutation. This method, for example, allows hardware to effectively reproduce a pre-selected set of sample locations for an array of 128&#xd7;128 sample bins from a smaller set of pre-selected sample locations for an array of 2&#xd7;2 sample bins. A permutation logic unit may use a first portion of an address for a sample bin B to identify a corresponding 2-D transformation, apply the inverse of the transformation to a second portion of the sample bin address to identify the corresponding bin of the 2&#xd7;2 array of sample bins, and apply the transformation to the sample locations stored in the corresponding bin to reproduce the sample locations pre-selected for sample bin B.

Method of creating a larger 2-D sample location pattern from a smaller one by means of X, Y address permutation

A graphics system applies multiple layers of texture information to triangles. The graphics system includes a hardware accelerator, a frame buffer and a video output processor. The hardware accelerator receives vertices of a triangle, identifies fragments of a sampling space which intersect the triangle, and applies the multiple layers of texture to the intersecting fragments. The multiple layers of textures may be stored in a texture memory external to the hardware accelerator. The hardware accelerator switches to a next texture layer after applying the textures of a current layer to all the fragments of the triangle. The hardware accelerator includes (or couples to) a texture accumulation buffer which stores color values associated with the triangle fragments between the application of successive texture layers. The frame buffer stores the samples and pixels generated from the samples by filtration. The video output processor transforms the pixels into a video signal.

Graphics data accumulation for improved multi-layer texture performance

In one embodiment, a scale and bias unit for use in a graphics system includes a preclamping unit configured to receive an input and to responsively generate an output value equal to a first value if the input is within a first input range. The scale and bias unit also includes a processing unit coupled to the preclamping unit and configured to perform a calculation on the input to generate the output value. The processing unit does not perform the calculation if the input is within the first input range.

System and method for performing scale and bias operations by preclamping input image data

A graphics system configured to apply multiple layers of texture information to batches of primitives. The graphics system collects primitives into a batch that share a common set of texture layers to be applied. The batch is limited so that the total estimate size of the batch is less than or equal to a storage capacity of a texture accumulation buffer. The graphics system stores samples (or fragments) corresponding to the batch primitives in the texture accumulation buffer between the application of successive texture layers.

Batch processing of primitives for use with a texture accumulation buffer

A graphics system comprises a rendering unit, a sample buffer and a sample-to-pixel calculation unit. The rendering unit receives graphics data specifying three triangle vertices, generates sample positions, and determines which samples reside inside the triangle. The rendering unit computes an axial rate of change of an ordinate based on the positions and ordinates of the vertices, and, for each sample residing inside the triangle, (a) multiplies the axial rate by a edge-relative sample displacement resulting in a first product, (b) interpolates a projection value for a projection point on a first edge of the triangle, and (c) adds the first product to the projection value resulting in a sample ordinate value. The sample buffer stores the sample ordinate value the samples inside the triangle. The sample-to-pixel calculation unit reads sample ordinate values from the sample buffer and generates a pixel value by filtering the sample ordinate values.

Interpolating sample values from known triangle vertex values

A graphics system configured to perform programmable filtering of samples to generate pixel values. The graphics system comprises a frame buffer, an accelerator unit and a video output processor. The accelerator unit receives graphics primitives, renders samples for the graphics primitives, and stores the rendered samples into a sample area of the frame buffer. The accelerator unit subsequently reads the samples from the sample area of the frame buffer, and filters the samples with a programmable filter having a programmable support region. The resulting pixel values are stored in a pixel area of the frame buffer. The video output processor reads the pixel values from the pixel area and converts the pixel values into a video signal which is provided to a video output port.

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Saratoga, CA, United States of America

Ranjit S Oberoi