third_party/glu/libtess/tessmono.h

/*
** License Applicability. Except to the extent portions of this file are
** made subject to an alternative license as permitted in the SGI Free
** Software License B, Version 1.1 (the "License"), the contents of this
** file are subject only to the provisions of the License. You may not use
** this file except in compliance with the License. You may obtain a copy
** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
** 
** http://oss.sgi.com/projects/FreeB
** 
** Note that, as provided in the License, the Software is distributed on an
** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
** 
** Original Code. The Original Code is: OpenGL Sample Implementation,
** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
** Copyright in any portions created by third parties is as indicated
** elsewhere herein. All Rights Reserved.
** 
** Additional Notice Provisions: The application programming interfaces
** established by SGI in conjunction with the Original Code are The
** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
** Window System(R) (Version 1.3), released October 19, 1998. This software
** was created using the OpenGL(R) version 1.2.1 Sample Implementation
** published by SGI, but has not been independently verified as being
** compliant with the OpenGL(R) version 1.2.1 Specification.
**
*/
/*
** Author: Eric Veach, July 1994.
**
** $Date$ $Revision$
** $Header: //depot/main/gfx/lib/glu/libtess/tessmono.h#5 $
*/

#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