00001 /* 00002 ** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008) 00003 ** Copyright (C) [dates of first publication] Silicon Graphics, Inc. 00004 ** All Rights Reserved. 00005 ** 00006 ** Permission is hereby granted, free of charge, to any person obtaining a copy 00007 ** of this software and associated documentation files (the "Software"), to deal 00008 ** in the Software without restriction, including without limitation the rights 00009 ** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 00010 ** of the Software, and to permit persons to whom the Software is furnished to do so, 00011 ** subject to the following conditions: 00012 ** 00013 ** The above copyright notice including the dates of first publication and either this 00014 ** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be 00015 ** included in all copies or substantial portions of the Software. 00016 ** 00017 ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 00018 ** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 00019 ** PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL SILICON GRAPHICS, INC. 00020 ** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 00021 ** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE 00022 ** OR OTHER DEALINGS IN THE SOFTWARE. 00023 ** 00024 ** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not 00025 ** be used in advertising or otherwise to promote the sale, use or other dealings in 00026 ** this Software without prior written authorization from Silicon Graphics, Inc. 00027 */ 00028 /* 00029 ** Author: Eric Veach, July 1994. 00030 */ 00031 00032 #ifndef SWEEP_H 00033 #define SWEEP_H 00034 00035 #include "mesh.h" 00036 00037 /* tessComputeInterior( tess ) computes the planar arrangement specified 00038 * by the given contours, and further subdivides this arrangement 00039 * into regions. Each region is marked "inside" if it belongs 00040 * to the polygon, according to the rule given by tess->windingRule. 00041 * Each interior region is guaranteed be monotone. 00042 */ 00043 int tessComputeInterior( TESStesselator *tess ); 00044 00045 00046 /* The following is here *only* for access by debugging routines */ 00047 00048 #include "dict.h" 00049 00050 /* For each pair of adjacent edges crossing the sweep line, there is 00051 * an ActiveRegion to represent the region between them. The active 00052 * regions are kept in sorted order in a dynamic dictionary. As the 00053 * sweep line crosses each vertex, we update the affected regions. 00054 */ 00055 00056 struct ActiveRegion { 00057 TESShalfEdge *eUp; /* upper edge, directed right to left */ 00058 DictNode *nodeUp; /* dictionary node corresponding to eUp */ 00059 int windingNumber; /* used to determine which regions are 00060 * inside the polygon */ 00061 int inside; /* is this region inside the polygon? */ 00062 int sentinel; /* marks fake edges at t = +/-infinity */ 00063 int dirty; /* marks regions where the upper or lower 00064 * edge has changed, but we haven't checked 00065 * whether they intersect yet */ 00066 int fixUpperEdge; /* marks temporary edges introduced when 00067 * we process a "right vertex" (one without 00068 * any edges leaving to the right) */ 00069 }; 00070 00071 #define RegionBelow(r) ((ActiveRegion *) dictKey(dictPred((r)->nodeUp))) 00072 #define RegionAbove(r) ((ActiveRegion *) dictKey(dictSucc((r)->nodeUp))) 00073 00074 #endif