raze/libraries/libtess/Source/sweep.h
2021-12-30 09:53:07 +01:00

74 lines
3.1 KiB
C

/*
** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
** Copyright (C) [dates of first publication] Silicon Graphics, Inc.
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**
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** 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
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** 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
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** this Software without prior written authorization from Silicon Graphics, Inc.
*/
/*
** Author: Eric Veach, July 1994.
*/
#ifndef SWEEP_H
#define SWEEP_H
#include "mesh.h"
/* tessComputeInterior( 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 tessComputeInterior( TESStesselator *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 {
TESShalfEdge *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 */
int inside; /* is this region inside the polygon? */
int sentinel; /* marks fake edges at t = +/-infinity */
int dirty; /* marks regions where the upper or lower
* edge has changed, but we haven't checked
* whether they intersect yet */
int 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