1 /* 2 ** License Applicability. Except to the extent portions of this file are 3 ** made subject to an alternative license as permitted in the SGI Free 4 ** Software License B, Version 1.1 (the "License"), the contents of this 5 ** file are subject only to the provisions of the License. You may not use 6 ** this file except in compliance with the License. You may obtain a copy 7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600 8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at: 9 ** 10 ** http://oss.sgi.com/projects/FreeB 11 ** 12 ** Note that, as provided in the License, the Software is distributed on an 13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS 14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND 15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A 16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT. 17 ** 18 ** Original Code. The Original Code is: OpenGL Sample Implementation, 19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics, 20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc. 21 ** Copyright in any portions created by third parties is as indicated 22 ** elsewhere herein. All Rights Reserved. 23 ** 24 ** Additional Notice Provisions: The application programming interfaces 25 ** established by SGI in conjunction with the Original Code are The 26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released 27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version 28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X 29 ** Window System(R) (Version 1.3), released October 19, 1998. This software 30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation 31 ** published by SGI, but has not been independently verified as being 32 ** compliant with the OpenGL(R) version 1.2.1 Specification. 33 ** 34 */ 35 /* 36 ** Author: Eric Veach, July 1994. 37 ** 38 ** $Date$ $Revision$ 39 ** $Header: //depot/main/gfx/lib/glu/libtess/sweep.h#5 $ 40 */ 41 42 #ifndef __sweep_h_ 43 #define __sweep_h_ 44 45 #include "mesh.h" 46 47 /* __gl_computeInterior( tess ) computes the planar arrangement specified 48 * by the given contours, and further subdivides this arrangement 49 * into regions. Each region is marked "inside" if it belongs 50 * to the polygon, according to the rule given by tess->windingRule. 51 * Each interior region is guaranteed be monotone. 52 */ 53 int __gl_computeInterior( GLUtesselator *tess ); 54 55 56 /* The following is here *only* for access by debugging routines */ 57 58 #include "dict.h" 59 60 /* For each pair of adjacent edges crossing the sweep line, there is 61 * an ActiveRegion to represent the region between them. The active 62 * regions are kept in sorted order in a dynamic dictionary. As the 63 * sweep line crosses each vertex, we update the affected regions. 64 */ 65 66 struct ActiveRegion { 67 GLUhalfEdge *eUp; /* upper edge, directed right to left */ 68 DictNode *nodeUp; /* dictionary node corresponding to eUp */ 69 int windingNumber; /* used to determine which regions are 70 * inside the polygon */ 71 GLboolean inside; /* is this region inside the polygon? */ 72 GLboolean sentinel; /* marks fake edges at t = +/-infinity */ 73 GLboolean dirty; /* marks regions where the upper or lower 74 * edge has changed, but we haven't checked 75 * whether they intersect yet */ 76 GLboolean fixUpperEdge; /* marks temporary edges introduced when 77 * we process a "right vertex" (one without 78 * any edges leaving to the right) */ 79 }; 80 81 #define RegionBelow(r) ((ActiveRegion *) dictKey(dictPred((r)->nodeUp))) 82 #define RegionAbove(r) ((ActiveRegion *) dictKey(dictSucc((r)->nodeUp))) 83 84 #endif 85
