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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