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mutter-performance-source/cogl/cogl-path/tesselator/tessmono.h
2016-04-22 16:44:31 +02:00

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/*
* 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.
**
*/
#ifndef __tessmono_h_
#define __tessmono_h_
/* __gl_meshTessellateMonoRegion( face ) tessellates a monotone region
* (what else would it do??) The region must consist of a single
* loop of half-edges (see mesh.h) oriented CCW. "Monotone" in this
* case means that any vertical line intersects the interior of the
* region in a single interval.
*
* Tessellation consists of adding interior edges (actually pairs of
* half-edges), to split the region into non-overlapping triangles.
*
* __gl_meshTessellateInterior( mesh ) tessellates each region of
* the mesh which is marked "inside" the polygon. Each such region
* must be monotone.
*
* __gl_meshDiscardExterior( mesh ) zaps (ie. sets to NULL) all faces
* which are not marked "inside" the polygon. Since further mesh operations
* on NULL faces are not allowed, the main purpose is to clean up the
* mesh so that exterior loops are not represented in the data structure.
*
* __gl_meshSetWindingNumber( mesh, value, keepOnlyBoundary ) resets the
* winding numbers on all edges so that regions marked "inside" the
* polygon have a winding number of "value", and regions outside
* have a winding number of 0.
*
* If keepOnlyBoundary is TRUE, it also deletes all edges which do not
* separate an interior region from an exterior one.
*/
int __gl_meshTessellateMonoRegion( GLUface *face );
int __gl_meshTessellateInterior( GLUmesh *mesh );
void __gl_meshDiscardExterior( GLUmesh *mesh );
int __gl_meshSetWindingNumber( GLUmesh *mesh, int value,
GLboolean keepOnlyBoundary );
#endif