Patent ID: 6222550
Filing Date: 2001-04-24
Classification: G06T

Abstract:
A parallel-triangle-pipeline 3D graphics system comprising:a triangle setup engine, coupled to receive triangle primitives representing three-dimensional 3D objects on a display screen, for generating attributes for three vertices and attribute gradients of the triangle;a first triangle pixel-pipeline, coupled to receive vertex attributes and surface gradients of a first triangle from the triangle setup engine, for generating pixel colors for pixels within the first triangle, the first triangle pixel-pipeline writing the pixel colors to a frame buffer for display on the display screen;a second triangle pixel-pipeline, coupled to receive vertex attributes and surface gradients of a second triangle from the triangle setup engine, for generating pixel colors for pixels within the second triangle, the first triangle pixel-pipeline writing the pixel colors to a frame buffer for display on the display screen;a plurality of first partial-pixel-address registers, coupled to the first triangle pixel-pipeline, each register for storing a Y address indicating a scan line on the display screen and a partial X address indicating a span-range of pixels within the scan line, wherein the first triangle pixel-pipeline accesses a pixel in the frame buffer within the span-range; andpixel coherency means, coupled to the plurality of first partial-pixel-address registers for the first triangle pixel-pipeline and coupled to the second triangle pixel-pipeline, for comparing a Y address and a partial X address for a requested pixel in the frame buffer to be accessed by the second triangle pixel-pipeline to the Y addresses and a partial X addresses stored in the plurality of first partial-pixel-address registers;wherein the second triangle pixel-pipeline is prevented from accessing the requested pixel in the frame buffer when the requested pixel is in a span-range stored during depth resolution in the first partial-pixel-address registers,whereby two triangle pixel-pipelines receive vertices, attributes and attribute gradients for two triangles processed in parallel and frame-buffer coherency is provided during depth resolution by comparing partial pixel addresses for a span-range of pixels on a scan line.