摘要:
Early Z scoreboard tracking systems and methods in accordance with the present invention are described. Multiple pixels are received and a pixel depth raster operation is performed on the pixels. The pixel depth raster operation comprises discarding a pixel that is occluded. In one exemplary implementation, the depth raster operation is done at a faster rate than a color raster operation. Pixels that pass the depth raster operation are checked for screen coincidence. Pixels with screen coincidence are stalled and pixels without screen coincidence are forwarded to lower stages of the pipeline. The lower stages of the pipeline are programmable and pixel flight time can vary (e.g., can include multiple passes through the lower stages). Execution through the lower stages is directed by a program sequencer which also directs notification to the pixel flight tracking when a pixel is done processing.
摘要:
A rasterizer stage configured to implement multiple interpolators for graphics pipeline. The rasterizer stage includes a plurality of simultaneously operable low precision interpolators for computing a first set of pixel parameters for pixels of a geometric primitive and a plurality of simultaneously operable high precision interpolators for computing a second set of pixel parameters for pixels of the geometric primitive. The rasterizer stage also includes an output mechanism coupled to the interpolators for routing computed pixel parameters into a memory array. Parameters may be programmably assigned to the interpolators and the results thereof may be programmably assigned to portions of a pixel packet.
摘要:
A present invention pixel processing system and method permit complicated three dimensional images to be rendered with shallow graphics pipelines including reduced gate counts and also facilitates power conservation. Pixel packet information includes pixel surface attribute values are retrieved in a single unified data fetch stage. At a data fetch pipestage a determination may be made if the pixel packet information contributes to an image display presentation (e.g., a depth comparison of Z values is performed determine if the pixel is occluded). A pixel packet status indicator (e.g., a kill bit) is set in the sideband portion of a pixel packet and the pixel packet is forwarded for processing in accordance with the pixel packet status indicator. The status indicator is a kill bit is set to prevent logic components from clocking information for a payload portion of the pixel packet if the status indicator indicates the pixel packet payload does not contribute to the image display presentation while continuing to clock pixel packet sideband information.
摘要:
A pixel processing system and method which permits rendering of complicated three dimensional images using a shallow graphics pipeline including reduced gate counts and low power operation. Pixel packet information includes pixel surface attribute values retrieved in a single unified data fetch stage. A determination is made if the pixel packet information contributes to an image display presentation (e.g., a depth comparison of Z values may be performed). The pixel packet information processing is handled in accordance with results of the determining. The pixel surface attribute values and pixel packet information are removed from further processing if the pixel surface attribute values are occluded. In one exemplary implementation, the pixel packet includes a plurality of rows and the handling is coordinated for the plurality of rows. Any of a number of downstream pipestages may remove the occluded pixel information, and in response thereto, may notify a gatekeeper pipestage of the slack increase so that more pixels can be allowed into the pipeline.
摘要:
A method of computing z parameters for pixels of a geometric primitive. The method includes the step of accessing the geometric primitive comprising a plurality of vertices, wherein each vertex comprises a plurality of associated parameters including a depth parameter, z. During rasterization of the geometric primitive, respective z values are interpolated for each pixel of the geometric primitive. Each z value is represented within a predefined numerical range which substantially corresponds to a depth range between a near plane and a far plane related to pixel rendering. During the interpolating, the z values are allowed to exceed the predefined numerical range and roll over within the predefined numerical range. A multi-bit indicator is used to indicate when a z value for a pixel is outside of the depth range.
摘要:
A method determining LOD values for a geometric primitive, in accordance with one embodiment of the present invention, includes accessing a plurality of geometric parameters of a vertex. An LOD value for a vertex is calculated as a function of the plurality of parameters of the vertex in a setup module. In a raster module an LOD value for a pixel is interpolated as a function of the LOD value of the pixel corresponding to the vertex and a view distance of the non-vertex pixel.
摘要:
Embodiments for programming a graphics pipeline, and modules within the graphics pipeline, are detailed herein. Several of these embodiments utilize offset registers associated with the instruction tables for the modules within the pipeline. The offset register serves as a pointer to locations in the instruction table, which allows instructions to be written to be instruction table, without requiring that the shader programs have explicit addresses. One embodiment describes a method of programming a graphics pipeline. This method involves accessing the shader program stored in memory. A shader instruction is generated from this shader program, and loaded into an instruction table associated with a target module graphics pipeline. The shader instruction is loaded into the instruction table at the location indicated by an offset register.
摘要:
A system and method for a data write unit in a 3-D graphics pipeline including generic cache memories. Specifically, in one embodiment a data write unit includes a first memory, a plurality of cache memories and a data write circuit. The first memory receives a pixel packet associated with a pixel. The pixel packet includes data related to surface characteristics of the pixel. The plurality of cache memories is coupled to the first memory for storing pixel information associated with a plurality of surface characteristics of a plurality of pixels. Each of the plurality of cache memories is programmably associated with a designated surface characteristic. The data write circuit is coupled to the first a memory and the plurality of cache memories. The data write circuit is operable under program control to obtain designated portions of the pixel packet for storage into the plurality of cache memories.
摘要:
Embodiments for programming a graphics pipeline, and modules within the graphics pipeline, are detailed herein. One embodiment described a method of implementing software assisted shader merging for a graphics pipeline. The method involves accessing a first shader program in memory, and generating a first shader instruction from that program. This first instruction is loaded into an instruction table at a first location, indicated by an offset register. A second shader program in memory is then accessed, and used to generate a second shader instruction. The second shader instruction is loaded into the instruction table at a second location indicated by the offset register.
摘要:
A method for loading and executing an indeterminate length shader program. The method includes accessing a first portion of a shader program in graphics memory of a GPU and loading instructions from the first portion into a plurality of stages of the GPU to configure the GPU for program execution. A group of pixels is then processed in accordance with the instructions from the first portion. A second portion of the shader program is accessed in graphics memory of the GPU and instructions from the second portion are loaded into the plurality of stages of the GPU to configure the GPU for program execution. The group of pixels are then processed in accordance with the instructions from the second portion.