Stellarium 0.15.2
tessmono.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
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
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,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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
23  * SOFTWARE.
24  *
25  * Except as contained in this notice, the name of Silicon Graphics, Inc.
26  * shall not be used in advertising or otherwise to promote the sale, use or
27  * other dealings in this Software without prior written authorization from
28  * Silicon Graphics, Inc.
29  */
30 /*
31 ** Author: Eric Veach, July 1994.
32 **
33 */
34 
35 #ifndef __tessmono_h_
36 #define __tessmono_h_
37 
38 /* __gl_meshTessellateMonoRegion( face ) tessellates a monotone region
39  * (what else would it do??) The region must consist of a single
40  * loop of half-edges (see mesh.h) oriented CCW. "Monotone" in this
41  * case means that any vertical line intersects the interior of the
42  * region in a single interval.
43  *
44  * Tessellation consists of adding interior edges (actually pairs of
45  * half-edges), to split the region into non-overlapping triangles.
46  *
47  * __gl_meshTessellateInterior( mesh ) tessellates each region of
48  * the mesh which is marked "inside" the polygon. Each such region
49  * must be monotone.
50  *
51  * __gl_meshDiscardExterior( mesh ) zaps (ie. sets to NULL) all faces
52  * which are not marked "inside" the polygon. Since further mesh operations
53  * on NULL faces are not allowed, the main purpose is to clean up the
54  * mesh so that exterior loops are not represented in the data structure.
55  *
56  * __gl_meshSetWindingNumber( mesh, value, keepOnlyBoundary ) resets the
57  * winding numbers on all edges so that regions marked "inside" the
58  * polygon have a winding number of "value", and regions outside
59  * have a winding number of 0.
60  *
61  * If keepOnlyBoundary is TRUE, it also deletes all edges which do not
62  * separate an interior region from an exterior one.
63  */
64 
65 int __gl_meshTessellateMonoRegion(GLUESface* face);
66 int __gl_meshTessellateInterior(GLUESmesh* mesh);
67 void __gl_meshDiscardExterior(GLUESmesh* mesh);
68 int __gl_meshSetWindingNumber(GLUESmesh* mesh, int value, GLboolean keepOnlyBoundary);
69 
70 #endif /* __tessmono_h_ */