HIGH SPEED IMAGE DRAWING METHOD AND APPARATUS THEREFOR

The tangent .alpha. of the tangential line of an image to be drawn at each point in an orthogonal X-Y coordinate system is classified into two angle regions, a first angle region, where a condition -1.ltoreq..alpha.<1 is fulfilled, and a second angle region, where a condition .alpha.<-1 or 1.ltoreq..alpha. is fulfilled. The first and the second angle region is represented by the direction parallel to the X-axis and the direction parallel to the Y-axis, respectively. When the image to be drawn is displayed on a display screen, in the image to be drawn, the parts belonging to the first angle region are drawn with a plurality of segments, each of which is parallel to the X-axis, and the parts blonging to the second angle region are drawn with a plurality of segments, each of which is parallel to the Y-axis. That is, the image to be drawn is displayed on the display screen by using only segments parallel to the X-axis and those parallel to the Y-axis.