Multi-stage fixed cycle pipe-lined lighting equation evaluator
AssigneeS3 Graphics Co., Ltd.
InventorsMike Hong, Dong-Ying Kuo, Mark Shuxin Zheng
Life of this patent
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Abstract
A lighting evaluation unit in a graphics processing system. The lighting evaluation unit includes a calculation unit having dot product circuitry used in determining specular, diffuse, spot, and attenuation components of a lighting equation in parallel. In one embodiment, the lighting evaluation unit is constructed in a pipeline manner, and includes multi-use circuitry for performing dot product calculations.
Claims16
A geometry engine in a graphics processing system, the geometry engine including a lighting engine, the lighting engine comprising:
- a light state register, the light state register storing data relating to light sources;
- and
- a light computation unit, the light computation unit configured to calculate effects on objects and including a plurality of stages, the plurality of stages includes a first stage, the first stage including dot product circuitry, the dot product circuitry further including circuitry for performing a plurality of multiplies in parallel, each of the plurality of multiplies generating a mantissa and an exponent, the plurality of stages configured to perform specular, diffuse, spot, and attenuation calculations, the plurality of stages further being arranged in a pipeline flow, with preceding stages providing data to succeeding stages.
A lighting computation unit of a lighting engine in a graphics processing system, the lighting computation unit comprising:
- an attenuation block configured to receive signals indicative of a position of a vertex and a position of a light source;
- a spot block;
- a diffuse block;
- and
- a specular block;
- with each of the attenuation block, the spot block, the diffuse block and the specular block including a dot product circuit, the dot product circuit of the attenuation block being configured to receive signals indicative of a vector from the position of the light source to the position of the vertex, the dot product circuitry further including circuitry for performing a plurality of multiplies in parallel, each of the plurality of multiplies generating a mantissa and an exponent.
Dependencies are inferred from the claim text.