[54] TEXTURE FILTER APPARATUS FOR COMPUTER GRAPHICS SYSTEM
[75] Inventors: Yu-Mhig Lin, Hsinchu; Chun-Kai Huang, Taichung; Wei-Kuo Chia. Hsinchu, all of Taiwan
[73] Assignee: 11 Kl-Industrial Technology Research Institute. Hsinchu, Taiwan
[21] Appl. No.: 598,521
[22] Filed: Feb. 8,1996
[51] Int CI.6 G06T 11/40
[52] U.S. CI 395/130; 395/131; 364/723
[58] Field of Search 395/130, 131,
395/132; 364/723. 734, 750.5. 759
[56] References Cited
U.S. PATENT DOCUMENTS
5,001,651 3/1991 Rehme et al 364/723 X
5,046,023 9/1991 Katsura et al. .
5,185,856 2/1993 Alcorn et al 395/130
5222205 6/1993 Larson et al 395/130
5268.681 12/1993 Lin et al 345/200
5268.682 12/1993 Yang et al 345/200
5287299 2/1994 Lin 364/759
5289,399 2/1994 Yoshida 364/759 X
5,321,425 6/1994 Chiaetal 345/200
5,422,657 6/1995 Wang et al 345/186
5,513,120 4/1996 Bedad 364/723
A process and apparatus are disclosed for obtaining a texture color value Cr for an object surface point from two texture color values CH and Crj (which themselves may be interpolated texture color values), of texture data points C, and C^. respectively. The object surface point is a distance W from the texture data point Q and a distance 1-W from the object surface point C^. where W is an n-bit value. The process includes the steps of multiplying each of the texture colors C„ and CrJ by each integer from 0 to 2""1 to produce 2"-l products for each color. The product of C„ with 2"_1-W and the product of CrJ with W are selected from these produced products, where W is the rounded product of W and 2"_1. The two selected products are added together to produce the sum (2"_1-W') C„+W Cr/. and the sum thus produced is divided by 2"_1 to produce the interpolated color. The apparatus for producing the interpolated color uses integer arithmetic for producing the texture color and can operate in a pipelined fashion.
7 Claims, 4 Drawing Sheets
