摘要:
A system for accessing texture data in a graphics rendering system allows texture data to be stored in memories with high latency or in a compressed format. The system utilizes a texture cache to temporarily store blocks of texture data retrieved from an external memory during rendering operations. In one implementation, geometric primitives are stored in a queue long enough to absorb the latency of fetching and possibly decompressing a texture block. The geometric primitives are converted into texture block references, and these references are used to fetch texture blocks from memory. A rasterizer rasterizes each geometric primitives as the necessary texture data becomes available in the texture cache. In another implementation, geometric primitives are converted into pixels, including a pixel address, color data, and a texture request. These pixels are stored in a queue long enough to absorb the latency of a texture block fetch. The texture requests are read from the queue and used to fetch the appropriate texture blocks. As texture data becomes available in the texture cache, the texture data is sampled as necessary and combined with the pixel data read from the queue to compute output pixels.
摘要:
A graphics rendering chip serially renders a stream of geometric primitives to image regions called chunks. A set-up processor in the chip parses rendering commands and the stream of geometric primitives and computes edge equation parameters. A scan-convert processor receives the edge equation parameters from the set-up processor and scan converts the geometric primitives to produce pixel records and fragment records. An internal, double-buffered pixel buffer stores pixel records for fully covered pixel addresses and also stores references to fragment lists stored in a fragment buffer. A pixel engine performs hidden surface removal and controls storage of pixel and fragment records to the pixel and fragment buffers, respectively. An anti-aliasing engine resolves pixel data for one pixel buffer while the pixel engine fills the other pixel buffer with pixel data for the next chunk.
摘要:
A gsprite engine circuit reads a display list identifying gsprite image layers to be composited for display, retrieves gsprite image data from an external memory, and transforms the gsprite data to display device coordinates. The gsprite image layers represent independently rendered graphical objects in a graphics scene. The gsprite engine can simulate the motion of the graphical objects in a sequence of display images by performing affine transformations on the gsprite image layers. The interface to the gsprite engine circuit includes the display list and gsprite header blocks. The display list enumerates the gsprites to be composited as a display image. The header blocks describe a gsprite transform, which can be an affine transform, used to transform gsprites to display device coordinates. The header blocks also provide an array of references to image blocks or "chunks" comprising the gsprite.
摘要:
A method for rendering graphical objects in a scene to generate a display images includes dividing the geometric primitives of models in a scene among portions or "chunks" of the view space to which the primitives will be rendered, and then rendering geometry referenced to the chunks in series in a common depth buffer. Geometry for a chunk can be rendered, including sophisticated anti-aliasing and translucency computations, using a minimum of memory. Serially rendering object geometry in chunks provides an effective form of compression because pixel fragments can be generated for one chunk at a time and then resolved. Pixel fragments can be resolved in a post-processing step for one chunk while primitives for another chunk are rasterized.
摘要:
In a graphics rendering system, an apparatus for resolving depth sorted lists of pixel fragments includes color and alpha accumulators for computing color and alpha values from the pixel fragments in a fragment list. Pixel fragments include color, alpha, coverage data. The coverage data describes how a geometric primitive covers sub-pixel regions of a pixel using a coverage mask. Pixel circuitry according to a clock-optimized approach includes separate color and alpha accumulators for computing color and alpha values for sub-pixel regions of a pixel. The accumulated color values are then summed and scaled to compute final color values for a pixel. To reduce hardware requirements, pixel circuitry in a hardware-optimized approach recognizes that some pixel regions have common accumulated alpha values as each fragment layer is processed. As such, color contributions for fragment layers can be computed using a single color accumulation operation for a pixel region having common alpha values.
摘要:
An API is provided that enables programmability of a 3D chip, wherein programming or algorithmic elements written by the developer can be downloaded to the chip, thereby programming the chip to perform those algorithms. A developer writes a routine that is downloadable to a 3D graphics chip. There are also a set of algorithmic elements that are provided in connection with the API that have already been programmed for the developer, that are downloadable to the programmable chip for improved performance. Thus, a developer may download preexisting API objects to a 3D graphics chip. A developer adheres to a specific format for packing up an algorithmic element, or set of instructions, for implementation by a 3D graphics chip. The developer packs the instruction set into an array of numbers, by referring to a list of ‘tokens’ understood by the 3D graphics chip. This array of numbers in turn is mapped correctly to the 3D graphics chip for implementation of the algorithmic element by the 3D graphics chip.
摘要:
Systems and methods are provided for controlling texture sampling in connection with computer graphics in a computer system. In various embodiments, improved mechanisms for controlling texture sampling are provided that enable 3-D accelerator hardware to greatly increase the level of realism in rendering, including improved mechanisms for (1) motion blur; (2) generating anisotropic surface reflections (3) generating surface self-shadowing (4) ray-cast volumetric sampling (4) self-shadowed volumetric rendering and (5) self-shadowed volumetric ray-casting. In supplementing existing texture sampling techniques, parameters for texture sampling may be replaced and/or modified.
摘要:
A three-dimensional API for communicating with hardware implementations of vertex shaders and pixel shaders having local registers. With respect to vertex shaders, API communications are provided that may make use of an on-chip register index and API communications are also provided for a specialized function, implemented on-chip at a register level, that outputs the fractional portion(s) of input(s). With respect to pixel shaders, API communications are provided for a specialized function, implemented on-chip at a register level, that performs a linear interpolation function and API communications are provided for specialized modifiers, also implemented on-chip at a register level, that perform modification functions including negating, complementing, remapping, stick biasing, scaling and saturating. Advantageously, these API communications expose these very useful on-chip graphical algorithmic elements to a developer while hiding the details of the operation of the vertex shader and pixel shader chips from the developer.
摘要:
A method for controlling the algorithmic elements in 3D graphics systems via an improved 3D graphics API is provided. In one aspect, the invention unifies separately provided 2D and 3D graphics APIs into a single graphics interface, thereby eliminating redundancy of functionality and unnecessary data types. As a result, a single mapping to various graphics objects replaces redundant mappings. A single texture download that optimizes the use of different graphics hardware is provided. A single instruction for effecting a resolution change is also provided.
摘要:
Systems and methods for downloading algorithmic elements to a coprocessor and corresponding processing and communication techniques are provided. For an improved graphics pipeline, the invention provides a class of co-processing device, such as a graphics processor unit (GPU), providing improved capabilities for an abstract or virtual machine for performing graphics calculations and rendering. The invention allows for runtime-predicated flow control of programs downloaded to coprocessors, enables coprocessors to include indexable arrays of on-chip storage elements that are readable and writable during execution of programs, provides native support for textures and texture maps and corresponding operations in a vertex shader, provides frequency division of vertex streams input to a vertex shader with optional support for a stream modulo value, provides a register storage element on a pixel shader and associated interfaces for storage associated with representing the “face” of a pixel, provides vertex shaders and pixel shaders with more on-chip register storage and the ability to receive larger programs than any existing vertex or pixel shaders and provides 32 bit float number support in both vertex and pixel shaders.