Abstract: A system and method for rendering a graphic object that recursively subdivides a frame buffer into rectangular regions in an order determined by a space-filling curve. Each rectangular region is tested to determine if the region includes at least part of the object to be rendered. If it contains at least part of the object to be rendered, then the region is subdivided. In accordance with the present invention, the same tests are performed on the subdivided regions. This proceeds until the size of a subdivided rectangular region reaches a predetermined limit, whereupon the pixels in the subdivided region are rendered on a pixel-by-pixel basis.

Abstract: A method of a computer graphics system recirculates texture cache misses into a graphics pipeline without stalling the graphics pipeline, increasing the processing speed of the computer graphics system. The method reads data from a texture cache memory by a read request placed in the graphics pipeline sequence, then reads the data from the texture cache memory if the data is stored in the texture cache memory and places the data in the pipeline sequence. If the data is not stored in the texture cache memory, the method recirculates the read request in the pipeline sequence by indicating in the pipeline sequence that the data is not stored in the texture cache memory, placing the read request at a subsequent, determined place in the pipeline sequence, reading the data into the texture cache memory from a main memory, and executing the read request from the subsequent, determined place and after the data has been read into the texture cache memory.

Abstract: The integers involved in the computation are embedded into a modular system whose index (i.e., its modulus) is an integer M that is bigger than all of these integers involved. In other words, these integers are treated not as belonging to ordinary integers anymore, but as “modular integers” belonging to the modular system indexed by M. Having completed the embedding, CRT provides the bridge which connects the single modular system indexed by M (ZM) with a collection of k modular systems indexed by m1,m2, . . . , mk respectively (Zm1, Zm2, . . . , Zmk), where M factorizes as m1*m2*m3* . . . *mk, and where each mi is slightly smaller than single precision. Then, after numbers are manipulated within modular arithmetic, the answer is reconstructed via the algorithm of CRT, also known as CRA. Finally, the present invention introduces the process of dinking that overcomes the major weakness of implementing division with modular arithmetic.

Abstract: In a computer system including a processor coupled to a memory via a bus, a system for a reduced instruction set graphics processing subsystem. The graphics processing subsystem is configured to accept graphics data from a computer system via a bus. The graphics processing subsystem is deeply pipelined to achieve high bandwidth, and is operable for processing graphics data including a first and second set of graphics instructions. The graphics instructions from the second set are more complex than the graphics instructions from the first set. The graphics processing subsystem also includes a built-in recirculation path for enabling the execution of graphics instructions by multi-pass. The graphics pipeline is streamlined such that the graphics instructions from the first set are processed efficiently. The graphics instructions from the second set are processed by using multi-pass via the recirculation path.

Abstract: The present invention pertains to an apparatus for and method of mapping texture memory to a texture cache such that cache contention is minimized. Significantly, in one embodiment of the present invention, addresses of the texture memory are mapped to entries of the texture cache according to a predetermined hashing scheme. According to the one embodiment, texture memory is addressed as a virtually contiguous address space by a multi-dimensional index. The multi-dimensional index is further partitioned into a low order bit field and a high order bit field. Low order bits of the multi-dimensional index are directly mapped to low order bits of the cache address. High order bits of the multi-dimensional index are mapped to high order bits of the cache address according to a predetermined address-hashing scheme. Particularly, in one embodiment, high order bits of the multi-dimensional index are selectively “exclusive-or-ed” to generate corresponding addresses of the texture cache.

Abstract: In a computer graphics system, a level of detail value is determined by calculating the maximum absolute difference between values of s and t coordinates of pixels diagonally adjacent to each other within a quad of pixels. In particular, the texels needed for the quad of pixels for each of two integer levels of detail surrounding the calculated diagonal level of detail are virtually guaranteed to be within a 4×4 footprint of texels projected into a texture memory. In addition, the texture value is determined by interpolating between 2 integer levels of detail without aliasing.

Abstract: The method and apparatus employ a texture filter in a graphics processor to perform a transform such as, for example, a Fast Fourier Transform. The texturizer can include an array of linear interpolators. The architecture reduces the computational complexity of the transform processes.

Abstract: The present invention comprises a system for implementing efficient context switching in a graphics computer system including a processor subsystem and a graphics pipeline. The system of the present invention includes a graphics pipeline configured to render 3D objects and a processor subsystem coupled to the graphics pipeline for executing a software process. A command buffer is coupled to the graphics pipeline for storing graphics commands from the software process and efficiently providing the graphics commands to the graphics pipeline. A shadow buffer is coupled to the command buffer and the graphics pipeline. The shadow buffer is adapted to store a state of the command buffer such that when the software process executing on the processor subsystem switches context, the shadow buffer implements an efficient context change by providing the state of the command buffer to the software process.

Abstract: The present invention provides a method for shading an image comprised of polygons in a graphics system. Each vertex of a polygon has x, y, and z coordinates, a normalized light source vector (L), a normalized surface normal vector (N), a normalized half-angle vector (H), and a specular exponent (s). The present invention selects a polygon and computes the angles between vectors N and L for each of the vertices. It also computes the difference terms between vectors N and H for each of the vertices. Then, the method of the present invention selects a pixel in the polygon to shade. It interpolates an angle between vectors N and L for the pixel based on the angles evaluated for the vertices. Based on the interpolated angle, a diffuse term for the pixel is determined. The present invention also determines a specular term for the selected pixel. It first interpolates a difference term between vectors N and H for the pixel based difference terms for each of the vertices.

Abstract: A method of a computer graphics system accelerates minified texture cache access by determining a starting address of a texture in s and t coordinates and a level of detail (LOD) of the texture. The texture includes tiles of texels stored in a memory. Then, the method of the present invention reads a succession of each of the tiles of the texture from the memory based on the starting address of a first of the succession of tiles. For each tile in the succession of tiles, each texel in the succession of texels being read is a distance of 2.sup.LOD texels from a previous texel in the succession of texels.

Abstract: A process and apparatus for quantum acceleration of a conventional computer by coupling a few quantum devices to the conventional computer. Initially, a first, second, and third maximally entangled qubit are prepared in a Greenberger-Horne-Zeilinger state. A fourth qubit is prepared in a perfect superposition of states which is unentangled from the three qubits. The second qubit is then measured and its measured value is input to the conventional computer. The conventional computer operates on this measured input value and performs an inverse oracle function. The second qubit is modified according to the output from the conventional computer. This modified qubit is used as one of two control inputs for controlling a quantum gate. The other control input is the fourth qubit. The quantum gate phase inverts the third qubit according to the two control inputs. A measurement of the complement of the first qubit is taken in order to produce the necessary quantum interference of the third qubit.

Abstract: A system and method for merging received pixel fragments with an existing fragment compares a depth range for the received fragment with a depth range for the existing fragment. If there is a range overlap, the new fragment is merged with the existing fragment for which there is overlap. If there is no range overlap, the new fragment is discarded. The merge operation can be performed for fragments received for a single surface, such as the nearest surface. Alternatively, the merge operation can be performed for fragments received for a plurality of surfaces.

Abstract: Texture mapping using triangular interpolation in a computer graphics system is discussed herein. A texture mapping module maps a pixel from an image space to a sample point in a texture space. The sample point has coordinates (si+sf, ti+tf). The texture mapping module identifies the three texels in the texture space that form a triangular region enclosing the sample point. The texture mapping module determines whether the triangular region represents a lower region or an upper region.

Abstract: A system and method for restoring bits of pixels prior to display where the original bits of the pixels were truncated compares each pixel to its neighbors to determine the relative value of each pixel as compared to its neighbors. First, the truncated pixel is shifted. That is, the remaining bits of the pixel are shifted to the left and additional bits are added in the least significant bit positions. Next, the pixel is compared to its neighbors to determine their relative values. For each neighbor that is greater than the pixel in question, the truncated shifted pixel is incremented by one. Similarly, for each neighbor that is less than the pixel in question, the truncated shifted pixel is decremented by one. Once the pixel is evaluated relative to its neighboring pixels, determination of the restored pixel is complete. The restored pixel can then be displayed.