| 摘要 |
PURPOSE:To provide the edged paint out area system capable of accurate plotting by providing a Z value preserving memory in a paint-out area, a paint-out area plotting means, and an edge plotting means performing edge plotting on a frame buffer and a Z buffer with the use of Z value of the Z value preserving memory. CONSTITUTION:This system consists of a trapezoid plotting means 1, the paint- out area plotting means 2, the edge plotting means 3, the Z value preserving memory 4, the frame buffer and the Z buffer 5, and CRT 6. The means 2 plots the paint-out area designated by the rightmost and leftmost coordinate values being input data in frame and Z buffers 5, and a paint-out area Z value preserving section 32 writes the value Z in the paint-out area in the memory 4. Therefore, the influence of the quantizing error caused by obtaining the value Z by increment method is eliminated, resulting in preventing the phenomena of discontinuing and blurring edges. |
