/* * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008) * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice including the dates of first publication and * either this permission notice or a reference to * http://oss.sgi.com/projects/FreeB/ * shall be included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * * Except as contained in this notice, the name of Silicon Graphics, Inc. * shall not be used in advertising or otherwise to promote the sale, use or * other dealings in this Software without prior written authorization from * Silicon Graphics, Inc. */ /* ** Author: Eric Veach, July 1994. ** */ #ifndef __sweep_h_ #define __sweep_h_ #include "mesh.h" /* __gl_computeInterior( tess ) computes the planar arrangement specified * by the given contours, and further subdivides this arrangement * into regions. Each region is marked "inside" if it belongs * to the polygon, according to the rule given by tess->windingRule. * Each interior region is guaranteed be monotone. */ int __gl_computeInterior( GLUtesselator *tess ); /* The following is here *only* for access by debugging routines */ #include "dict.h" /* For each pair of adjacent edges crossing the sweep line, there is * an ActiveRegion to represent the region between them. The active * regions are kept in sorted order in a dynamic dictionary. As the * sweep line crosses each vertex, we update the affected regions. */ struct ActiveRegion { GLUhalfEdge *eUp; /* upper edge, directed right to left */ DictNode *nodeUp; /* dictionary node corresponding to eUp */ int windingNumber; /* used to determine which regions are * inside the polygon */ GLboolean inside; /* is this region inside the polygon? */ GLboolean sentinel; /* marks fake edges at t = +/-infinity */ GLboolean dirty; /* marks regions where the upper or lower * edge has changed, but we haven't checked * whether they intersect yet */ GLboolean fixUpperEdge; /* marks temporary edges introduced when * we process a "right vertex" (one without * any edges leaving to the right) */ }; #define RegionBelow(r) ((ActiveRegion *) dictKey(dictPred((r)->nodeUp))) #define RegionAbove(r) ((ActiveRegion *) dictKey(dictSucc((r)->nodeUp))) #endif