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:
An arithmetic logic unit (ALU) in a graphics processor is described. The ALU includes circuitry for performing an operation using a first set of pixel data. The first set of pixel data is resident in a pipeline register coupled to the circuitry. A temporary register is coupled to the circuitry. The temporary register can receive a result of the operation. The temporary register allows a result generated using one set of pixel data to be used with a subsequent set of pixel data in the same ALU. The result of the operation can thus be used in a second operation with a second set of pixel data that resides in the pipeline register after the first set of pixel data.
摘要:
A graphics processor is disclosed having a programmable Arithmetic Logic Unit (ALU) stage for processing pixel packets. Scalar arithmetic operations are performed in the ALUs to implement a graphics function.
摘要:
A graphics processor displays pixels in an image at non-uniform resolution, using a maximum resolution in the interior of a surface in the image, and a lower resolution at edges. Higher color resolution in the interior eliminates color aliasing that would otherwise be caused if the interior were displayed at the lower resolution. Lower resolution at the edges is not noticeable to the human eye, and allows the graphics processor to use one or more low resolution color signals in generating the displayed image, thereby reducing hardware (e.g. memory locations required to store such signals, and lines required to route such signals). One such processor (not necessarily a graphics processor) includes a resolution reducer and a resolution enhancer that respectively reduce and enhance the resolution of a signal. Specifically, the resolution reducer reduces the resolution of a high resolution signal to generate a low resolution signal. The resolution enhancer enhances the low resolution signal to generate a signal (called “enhanced resolution signal”) having the same number of bits as the high resolution signal. One such resolution reducer simply drops a number of least significant bits to generate a low resolution signal, and the corresponding resolution enhancer passes, as the enhanced resolution signal, the low resolution signal and the above-described number of least significant bits of a high resolution signal. The enhanced resolution signal is not a significant aspect of one embodiment because in some embodiments the low resolution signal and the high resolution signal are used directly.
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:
Vertex data can be accessed for a graphics primitive. The vertex data includes homogeneous coordinates for each vertex of the primitive. The homogeneous coordinates can be used to determine perspective-correct barycentric coordinates that are normalized by the area of the primitive. The normalized perspective-correct barycentric coordinates can be used to determine an interpolated value of an attribute for the pixel. These operations can be performed using adders and multipliers implemented in hardware.
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.