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sweep.h
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1/*
2 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
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9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice including the dates of first publication and
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14 * http://oss.sgi.com/projects/FreeB/
15 * shall be included in all copies or substantial portions of the Software.
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18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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29 */
30/*
31** Author: Eric Veach, July 1994.
32**
33*/
34
35#ifndef __sweep_h_
36#define __sweep_h_
37
38#include "mesh.h"
39
40/* __gl_computeInterior( tess ) computes the planar arrangement specified
41 * by the given contours, and further subdivides this arrangement
42 * into regions. Each region is marked "inside" if it belongs
43 * to the polygon, according to the rule given by tess->windingRule.
44 * Each interior region is guaranteed be monotone.
45 */
47
48
49/* The following is here *only* for access by debugging routines */
50
51#include "dict.h"
52
53/* For each pair of adjacent edges crossing the sweep line, there is
54 * an ActiveRegion to represent the region between them. The active
55 * regions are kept in sorted order in a dynamic dictionary. As the
56 * sweep line crosses each vertex, we update the affected regions.
57 */
58
60 GLUhalfEdge *eUp; /* upper edge, directed right to left */
61 DictNode *nodeUp; /* dictionary node corresponding to eUp */
62 int windingNumber; /* used to determine which regions are
63 * inside the polygon */
64 GLboolean inside; /* is this region inside the polygon? */
65 GLboolean sentinel; /* marks fake edges at t = +/-infinity */
66 GLboolean dirty; /* marks regions where the upper or lower
67 * edge has changed, but we haven't checked
68 * whether they intersect yet */
69 GLboolean fixUpperEdge; /* marks temporary edges introduced when
70 * we process a "right vertex" (one without
71 * any edges leaving to the right) */
72};
73
74#define RegionBelow(r) ((ActiveRegion *) dictKey(dictPred((r)->nodeUp)))
75#define RegionAbove(r) ((ActiveRegion *) dictKey(dictSucc((r)->nodeUp)))
76
77#endif
unsigned char GLboolean
Definition: GL_glu.h:267
GLboolean fixUpperEdge
Definition: sweep.h:69
DictNode * nodeUp
Definition: sweep.h:61
GLboolean dirty
Definition: sweep.h:66
GLUhalfEdge * eUp
Definition: sweep.h:60
int windingNumber
Definition: sweep.h:62
GLboolean inside
Definition: sweep.h:64
GLboolean sentinel
Definition: sweep.h:65
int __gl_computeInterior(GLUtesselator *tess)
Definition: sweep.c:1301