HIGH-SPEED DRAWING SYSTEM FOR HORIZONTAL LINE VECTOR

摘要

PURPOSE:To draw graphic at a high speed by providing a function to a raster address register to designate a Y-direction position where a horizontal line is drawn and a function to a horizontal line section register to decide a specific section in a single raster that is turned into black when a Y-direction position is detected. CONSTITUTION:A raster register 2 stores an address showing a raster position where a segment should be drawn. A horizontal line section register 3 divides a single raster (horizontal line drawn in the raster direction) shown by the register 2 into several sections and sets a single bit opposite to each section. Plural pairs of these registers 2 and 3 are provided. When a lateral segment drawn is detected, the information are set at both registers 2 and 3 for the segments included in the section of the horizontal segment. Then the horizontal lines are drawn based on the information set at those registers 2 and 3 without using the Bresnham method. Thus the horizontal segments can be drawn at a high speed and the graphics are also drawn at a high speed.