Display system having floating point rasterization and floating point framebuffering

Abstract

A floating point rasterization and frame buffer in a computer system graphics program. The rasterization, fog, lighting, texturing, blending, and antialiasing processes operate on floating point values. In one embodiment, a 16-bit floating point format consisting of one sign bit, ten mantissa bits, and five exponent bits (s10e5), is used to optimize the range and precision afforded by the 16 available bits of information. In other embodiments, the floating point format can be defined in the manner preferred in order to achieve a desired range and precision of the data stored in the frame buffer. The final floating point values corresponding to pixel attributes are stored in a frame buffer and eventually read and drawn for display. The graphics program can operate directly on the data in the frame buffer without losing any of the desired range and precision of the data.

1 . In a rendering circuit, a method for operating on data stored in a frame buffer, the method comprising:
 storing the data in the frame buffer in a floating point format;   reading the data from the frame buffer in the floating point format; and   writing the data to the frame buffer in the floating point format,   writing, storing, and reading the data in the frame buffer in the floating point format further comprising a specification of the floating point format, wherein the specification corresponds to a level of range and precision.   
     
     
         2 . The method as defined by  claim 1  further comprising operating directly on the data in the floating point format. 
     
     
         3 . The method as defined by  claim 2  wherein storing is performed before reading, reading is performed before operating, and operating is performed before writing. 
     
     
         4 . The method as defined by  claim 1  wherein storing is performed before reading, reading being performed before writing.