DISCRIMINATING METHOD FOR OUTER GRAPHIC AND INNER GRAPHIC IN GRAPHIC PROCESSOR

摘要

PURPOSE:To discriminate exactly an outer graphic and an inner graphic by tracking a subdivided segment in a state that a segment superposed at the smallest angle becomes the next segment, when the present segment is rotated clockwise or counterclockwise centering around the end point of the present segment at the time of tracking, and forming two kinds of segment aggregations. CONSTITUTION:When an advance is executed in a prescribed direction P by setting one optional point on a graphic as an origin, and this present segment 9 has been rotated clockwise alpha or counterclockwise beta, centering around the end point of the present segment 9 (the end point in the advance direction) at the time of tracking, tracking is executed by setting a segment 10 superposed at the smallest angle as the next segment. Also, from a relation of a detecting direction of the next vector and directions of vectors 1-11, two kinds of segment aggregations of R and L are formed, and the maximum value to the X axis is detected. When detecting the next vector, the present segment 9 is rotated in the prescribed direction alpha or beta, but whether a locus of this rotational segment (tracking line) passes through the left side of the maximum value or not is decided therein, and if it passes through the left side, it is discriminated that the segment aggregation is an inside graphic, and if not so, it is discriminated to be an outside graphic.