The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 20, 2001
Filed:
Dec. 17, 1998
Richard J. Fuller, Lexington, MA (US);
ATI International SRL, Hasting, BB;
Abstract
A method and apparatus for approximating exponential and other nonlinear functions in a graphics system is accomplished using a linear interpolator adapted to receive a graphics primitive that includes vertex values for a parameter at each vertex of the graphics primitive. The linear interpolator determines a linear interpolation value for the parameter at a selected pixel within the primitive based on the vertex values. The linear interpolation value is then used to generate a first index and a fractional value, where the fractional value is the difference between the linear interpolation value and the first index. The first index is then incremented to produce a second index. The first and second indexes are then applied to a memory block that stores a discrete sampling of a nonlinear function corresponding to the parameter. The first index and the second index correspond to sample points of the nonlinear function, and the memory block provides a first sample and a second sample of the nonlinear function in response to the first and second indexes. An arithmetic unit then combines the first and second samples using the fractional value to determine a value for the parameter at the selected pixel.