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mutter-performance-source/cogl/cogl-path/tesselator/sweep.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 __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