summaryrefslogtreecommitdiff
path: root/src/glu/sgi/libtess/sweep.h
blob: cadeba94e04a6f7ed3207eff5f1bf2ce6f1c1b52 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
/*
 * 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.
**
** $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $
** $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libtess/sweep.h,v 1.1 2001/03/17 00:25:41 brianp Exp $
*/

#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