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:
Aug. 20, 2002
Filed:
May. 30, 1997
S. Paul Tucker, Ft. Collins, CO (US);
Bradly J. Foster, Ft. Collins, CO (US);
Steven J. Kommrusch, Ft. Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A computer graphics system includes an apparatus for fog blending colors to be displayed on a graphics display of the computer graphics system. The computer graphics system includes a rendering parameter calculation unit responsive to data of a primitive, that determines a cooked exponent value and a color value for at least one pixel of the primitive. In addition, the system includes a fog unit responsive to the cooked exponent value for each pixel of the primitive, that determines a fog blending factor for each pixel of the primitive, wherein the fog blending factor is one of an exponential fog blending factor and an exponential-squared fog blending factor. Further, the system includes a fog blending unit responsive to the color value and the fog blending factor for each pixel of the primitive and also to a fog color value, that blends the fog color value with the color value for each pixel of the primitive according to the fog blending factor for the respective pixel, and that provides a fogged color value for each pixel of the primitive. In addition, the computer graphics system may include a first interpolator, responsive to the color value and the cooked exponent value for at least one pixel of the primitive, that determines the color value and the cooked exponent value along an edge of the primitive so as to provide the cooked exponent value and the color value for each pixel of the edge of the primitive. Further, the computer graphics system may also include a second interpolator, responsive to the cooked exponent value and the color value for each pixel of the edge of the primitive, that determines the cooked exponent value and the color value along a span of the primitive so as to provide the cooked exponent value and the color value for each pixel of the span of the primitive. In this way, the system provides fast and accurate exponential and exponential-squared fog blending of the color values of the primitive without a lot of hardware.