| 摘要 |
PROBLEM TO BE SOLVED: To execute display without disturbance without executing a geometrical cutting processing by obtaining a range in a view coordinate system in an area where a plotting processing is possible after perspective transformation and preventing the maximum length of a graphic from exceeding the shortest distance from a view volume to the boundary of the range. SOLUTION: The graphic being a display object is divided (step 91) so that they become not more than a prescribed size, and the coordinates of the apexes of the divided graphics, namely polygons are transformed into the view coordinate system (step 921). Then, whether the objective graphic is completely in front of a former clip face or not is judged (step 922). When it is not, whether the objective graphic is completely behind a back clip face or not is judged (step 923). When it is not, perspective transformation is executed (step 924). Whether the objective graphic is completely out of upper/lower/left/right faces or not is judged (step 925). When it is not, the objective graphic is transformed into a device coordinate system being the coordinate system on a frame buffer (step 926). |
