Texture mapping apparatus computing texture address by fill address

Abstract

A texture mapping apparatus applies a texture pattern to an image which two-dimensionally represents a three-dimensional object so as to display a surface structure of the object. A frame memory is provided with storage locations identified by addresses for storing image data representative of the image of the object pixel by pixel. A texture memory is provided with storage locations identified by addresses for storing texture data representative of the texture pattern. A CPU inputs fill coordinates to determine an area of the image to which the texture pattern is applied. Further, the CPU separately inputs texture coordinates to determine a corresponding area of the texture pattern which is applied to the area of the image. A fill address generator operates based on the fill coordinates for generating fill addresses of the frame memory which correspond to pixels in the area of the image. A texture address generator operates based on the texture coordinates for generating texture addresses of the texture memory which correspond to the fill addresses. A selector is operated to read out the texture data from the storage locations of the texture memory which are designated by the texture addresses, and to write the read texture data into storage locations of the frame memory which are designated by the corresponding fill addresses.