Abstract: The current algorithms of the polygons’ boolean operations can give correct results rapidly enough in general cases. But there are errors when it comes to queer conditions. This paper proposes a method to analyze queer conditions using concept of graphic interior angle, and gives a new overall algorithm of queer’s treatment on the basis of the original intersection-traversal algorithms’ framework. Compared with other algorithms of polygons’ boolean operations, the algorithm in this paper is more simple and effective for analysis of queer conditions.

Key words: computational geometry, polygons&rsquo, boolean operation, graphic interior angle’s boolean operations, queer conditions