Synchronize with trunk's revision r57629.
[reactos.git] / dll / opengl / glu32 / src / libtess / sweep.h
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
13 * either this permission notice or a reference to
14 * http://oss.sgi.com/projects/FreeB/
15 * shall be included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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20 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
21 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
22 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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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 */
46 int __gl_computeInterior( GLUtesselator *tess );
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
59 struct ActiveRegion {
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