dongli/TTS — Issue #1: Multiple crossing vertices problem
Author: dongli
Created: 2012-02-18 02:02:27+00:00
State: open

When there is one crossing vertex in a polygon, the polygon must be split at that vertex with mode 5. But if there are more than one crossing vertex (recorded in a list), problem may occur during the iterative splitting, because we do not know if a polygon that has a vertex in the crossing vertices list should be split or not. The normal polygon may be erroneously split, and program will crash.

Thus we must define a mark that can be used to identify the polygons that need to be split. The difficulty is that the new polygons, generated during the splitting of old crossing polygon, may replace the old one to become the polygons that must be split. So how do we identify those new polygons?