International Business Machines Corporation

Cirrus Logic Inc.

S3 Incorporated, Inc.

Mark Alan Einkauf

Michael Terrell Vanover

Thomas A Dye

Michael K Larson

Goran Devic

Jaroslaw R Rossignac

Thomas M Ogletree

Michael Martin Klock

Jimmie Darius Edrington

Jeffrey W Wu

Allen Peter Jensen

Ngocha T Le

A method and apparatus that adjusts certain graphics processing procedures based on a selectable speed/quality (S/Q) adjustment gauge. The S/Q adjustment can be tuned within a predetermined range (e.g., 0 to 255) where on one side, speed is represented over image quality while on the other side, image quality is represented over speed. Settings between the ends give proportional representation for speed and quality. A first graphics process determines whether linear or perspective texture mapping processes are to be used on the selected polygon based on: 1) the size of the polygon measured against a predetermined size threshold; and 2) the relative perspective of the polygon measured against a perspective threshold. The S/Q setting alters these thresholds to alter the operation of the first graphics procedure. A second graphics process splits a selected polygon graphics primitive based on the relative perspective of the polygon compared to a predetermined perspective threshold. The S/Q setting alters the predetermined perspective threshold to alter the operation of the second graphics procedure. A third graphics process splits the selected polygon based on: 1) the size of the polygon; and 2) the orthogonal span of the polygon. The S/Q setting alters the operation of the third graphics procedure. Lastly, a fourth graphics process selects either fixed point or floating point calculations for certain graphics operations on the primitive. The S/Q setting alters the thresholds for the selection within the fourth graphics procedure.

Method and apparatus for adjusting graphics processing procedures based

A polygon vertex sorting circuit for a three dimensional graphics computer system. The system of the present invention includes a swap configuration circuit coupled to receive a plurality of vertex address corresponding to a plurality of vertices of a polygon. The swap configuration circuit is coupled to an address input bus to receive the plurality of vertex addresses. An address output interface circuit is coupled to the swap configuration circuit. The address output interface circuit interfaces the output of the swap configuration circuit with an address output bus. A control circuit is coupled to the swap configuration circuit and the output interface circuit. The control circuit sorts the plurality of vertices by configuring the swap configuration circuit and the address output interface circuit to output a swapped vertex address via the address output bus in response to receiving one of the plurality of vertex addresses via the address input bus.

Method and system for efficient register sorting for three dimensional

A method for computing input parameters used in a non-homogeneous second order perspective texture mapping process using interpolation. The present invention receives a polygon primitive (e.g., triangle) including screen display coordinates and texture map coordinates for each vertex (vmin, vmid, and vmax). Based on vertex information including perspective weights, w, screen display coordinates and texture map coordinates are determined for midpoints (i and j) of the two triangle slopes opposite the triangle's major slope. Based on a determined quadratic equation of the triangle's major slope, screen coordinates and texture map coordinates are determined at several selected points (e.g., imain, jmain, and midmain) along the major slope that corresponds to the i, j, and vmid points. From these values, quadratic coefficients a1, a2, and du.sub.-- ortho.sub.-- add are computed and also quadratic coefficients b1, b2 and dv.sub.-- ortho.sub.-- add are computed. The above values, parameters u.sub.-- main, du.sub.-- main (change in u over change in y), d2u.sub.-- main (change in .DELTA.u over change in .DELTA.y), du.sub.-- ortho (change in u over change in x), d2u.sub.-- ortho (change in .DELTA.u over change in .DELTA.x), v.sub.-- main, dv.sub.-- main (change in v over change in y), d2v.sub.-- main (change in .DELTA.v over change in .DELTA.y), dv.sub.-- ortho (change in v over change in x), and d2v.sub.-- ortho (change in .DELTA.v over change in .DELTA.x) are computed and forwarded to a non-homogenous second order perspective texture mapping process using interpolation. The above texture mapping process is extremely efficient as it is free of division operations during the interpolation.

Method for computing parameters used in a non-homogeneous second order

The system and method of the present invention performs an iterative operation that subdivides selected polygons (e.g., triangles) having high perspective ratios into a plurality of smaller polygons to limit artifact creation during the rendering/texture map processes. The present invention is particularly well suited for interpolation driven rendering/texture map processes. Processing logic of the present invention analyzes each polygon stored in display list memory of a graphics accelerator or graphics subsystem and determines a perspective ratio between adjacent vertices of the polygon. If the perspective ratio is greater than a pre-selected limit, the edge bounded by the vertices is subdivided at the mid-point and new polygons are created. The process is iterative until all polygons have perspective ratios that are less than the pre-selected limit, at which time the object data can be displayed by the hardware. Perspective values (w) and three dimensional coordinates (x, y, z) for each created mid-point are calculated by averaging the perspective values at the vertices bounding the edge. Texture coordinates at the mid-point of a divided edge (umid, vmid) are calculated and then interpolated across the resulting polygon to determine the texels values of the image at each pixel within the boundary of the polygon. The present invention eliminates artifact creation when used with interpolation driven rendering/texture map processes that might otherwise not properly process polygons with large perspective.

Method for triangle subdivision in computer graphics texture mapping to

An apparatus for processing high level instructions including a plurality of processing units, means for generating a plurality of instructions to perform said high level instructions, and means for dynamically organizing said generated instructions into at least one group, each group including at least one instruction to be processed by one of said processing units. In addition, a method of processing high level instructions by a plurality of processing units including generating a plurality of instructions to perform said high level instructions, and dynamically organizing said generated instructions into at least one group, each group including at least one instruction to be processed by one of said processing units.

Dynamic load balancing for a multiprocessor pipeline by sorting

A system and method is provided for displaying trimmed surfaces on a computer graphics system. The present invention tessellates a three-dimensional surface into triangles and determines whether a trimming curve intersects any triangles. If an intersection occurs, a polygon trimming mask is formed by performing an exclusive OR operation and rendering the polygon into a mask plane. The XOR operation sets the bits in the mask plane corresponding to the trimming mask to logical 1. The rendering hardware then compares the bits in the mask plane with the bits in the frame buffer and draws those pixels which correspond to the bits set to 1 in the mask plane. Since, the trimming mask is a polygon the rendering hardware can perform shading, or lighting calculations using values for points which are contained on the tessellated triangle. In this manner, consistent lighting of a trimmed surface can be achieved. Additionally, the present invention provides for the formation of multiple trimming masks when multiple trimming curves intersect a tessellated triangle. The multiple trimming masks are sequentially XORed into the mask plane and the corresponding pixels are then drawn.

System and method for displaying trimmed surfaces using bitplane masking

A method for producing realistic shading of three-dimensional objects depicted in a graphics display system. Computationally efficient Gouraud shading is practiced in the rendering of images which routinely require Phong shading to obtain suitable realism. Gouraud shading is adaptively applied to polygon regions of preferably triangular shape at a granularity defined by heuristically derived relationships using surface normal vectors, incident light vectors and relative pixel separation information. When division of the base triangle is dictated, the methodology produces a mesh of polygons sized to be individually rendered with Gouraud shading yet provide Phong-like realism for the whole of the original polygon region.

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Leander, TX, United States of America

Mark Alan Einkauf