Patent · US Expired

Graphics accelerator with shift count generation for handling potential fixed-point numeric overflows

US6037947A · kind A · utility

26Cited by
7References
51Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 16, 1997
Grant dateMar 14, 2000
Priority date
Expiry dateOct 16, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06T1/20
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A 3-D graphics accelerator for performing lighting operations using operands within a given fixed point numeric range. The 3-D graphics accelerator includes a first computational unit which is configured to compute a value of an attenuation factor usable for performing said lighting operation for local lights. The attenuation factor is represented in floating point format. The first computational unit is also configured to represent the attenuation factor in an intermediate format including a first intermediate value (a scaled attenuation factor value within the given fixed point numeric range), and a second intermediate value (a shift count usable to convert the scaled attenuation factor value back to the original attenuation factor value). The 3-D graphics accelerator further includes a lighting unit coupled to said first computational unit. The first computational unit is further configured to convey the intermediate representation of the attenuation factor to the lighting unit. The lighting unit performs lighting calculations in fixed point, using operands within the given numeric range (such as the scaled attenuation factors). The lighting unit generates intermediate color val…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.