Patent ID: 6275241
Filing Date: 2001-08-14
Classification: G06T,G09G

Abstract:
A three-dimensional image drawing apparatus comprising:a frame buffer for storing display data corresponding to a display apparatus display screen;a two-dimensional drawing circuit for performing coordinate operations in order to draw specific two-dimensional images to said frame buffer;a Z buffer for storing depth data for performing three-dimensional drawing to said frame buffer;a three-dimensional straight line drawing circuit for performing three-dimensional drawing to said frame buffer based on said depth data stored in said Z buffer;a memory control circuit for controlling access to the buffers; anda bit number altering circuit for altering the number of bits per pixel in coordinate operations in said two-dimensional drawing circuit either to a number of bits corresponding to drawing data in said frame buffer or to a number of bits corresponding to depth data in said Z buffer; wherein:areas of said frame buffer and Z buffer are established in same physical memory; andsaid bit number altering circuit selectively performs drawing to said frame buffer and setting of depth data to said Z buffer by coordinate operations of said two-dimensional drawing circuit, by altering the number of bits per pixel in the coordinate operations of said two-dimensional drawing circuit.