Network Computing Devices, Inc.

Other

Kevin B Martin

Ralph G Martin

The present invention is a method and apparatus for executing three-operand raster operation in two-operand raster environments. Structurally, the present invention includes a lookup table having one entry for each three-operand raster operation which is to be emulated. The entry associated with a particular three-operand raster operation includes a template and zero or more two-operand raster operations. Execution of the three-operand raster operation begins by retrieving the lookup table entry associated with the three-operand raster operation. Each two-operand raster operation in the lookup table entry is then executed in sequence. During execution, the template is used to provide a mapping which chooses which operands of the three-operand raster operation will be used as operands for the two-operand raster operation in the sequence.

Raster operation lookup and execution

A method for rendering of three dimensional images on a video subsystem which does not include clearing of the Z buffer at each frame includes establishment of a Z buffer and a sequence number in memory, where the sequence number is incremented with each successive frame rendered and the Z buffer is cleared when the sequence number reaches a predetermined value; the Z buffer is thus recycled a number of times between clears. In a more elaborate implementation, the precision of the Z buffer is adjusted to permit clearing of the Z buffer to occur either as the result of the sequence number reaching a predetermined value or as the result of the accrual of a predetermined amount of time allocated for clearing, referred to as scheduling. The scheduling method can be applied to a wide range of accounting tasks within a system. In addition, a related method for recycling the image buffer is also disclosed in which multiple colormap ID's are used to distinguish data included in a current frame from data in a prior frame, where the colormap ID's associated with the prior frames all map to the background color, leaving to be displayed only the data of the current frame.

Method for process scheduling in a processor based system

Video buffer recycling method and apparatus

A line-draw method and apparatus that draws lines at fast speeds. Lines are drawn a pixel at a time and a number of algorithms are employed to determine the pixels to be drawn. The line-draw method determined is a function of line length, typical length categories are short, medium and long. For short lines, a table look-up method is employed. For longer length lines, a multi-pixel segment method (burst method) is employed. Burst methods are line-draw methods which draw lines using a plurality of multi-pixel segments to draw the lines where each segment is characterized as having a number (U) of unconditional pixels which are always drawn and an actual number (A) of conditional pixels which are drawn. The actual number (A) is any number up to a maximum number (C) of conditional pixels which can be drawn.

Line draw method for generating, storing and displaying lines in a

A resistance temperature detector for rapidly sensing temperatures in an operating environment by means of changes in the current through an element whose electrical resistance varies with temperature includes a fine wire coil whose electrical resistance varies with temperature, and a deposited coating of a rigid, coherent mineral, such as diamond, which is deposited over the fine wire coil.

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San Jose, CA, United States of America

Kevin B Martin