From a0c4815433ccd57322f4f7703ca35e9ccfa59250 Mon Sep 17 00:00:00 2001
From: marha <marha@users.sourceforge.net>
Date: Thu, 8 Oct 2009 13:15:52 +0000
Subject: Added MesaLib-7.6

---
 mesalib/src/glu/sgi/libnurbs/nurbtess/partitionY.h | 97 ++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 mesalib/src/glu/sgi/libnurbs/nurbtess/partitionY.h

(limited to 'mesalib/src/glu/sgi/libnurbs/nurbtess/partitionY.h')

diff --git a/mesalib/src/glu/sgi/libnurbs/nurbtess/partitionY.h b/mesalib/src/glu/sgi/libnurbs/nurbtess/partitionY.h
new file mode 100644
index 000000000..8dda409de
--- /dev/null
+++ b/mesalib/src/glu/sgi/libnurbs/nurbtess/partitionY.h
@@ -0,0 +1,97 @@
+/*
+ * 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.
+ */
+/*
+ *partitionY.h:
+ *partition a polygon into a Y-monotone polygon:
+ * A polygon is Y-monotone if the boundary can be split into two polygon chains
+ *A and B such that each chain is Y-monotonic that is the intersection of any
+ *horizontal line intersects each chain has at most one connected componenets
+ * (empty, single point or a single line).
+ * 
+ * A vertex is a cusp if both its ajacent vertices are either at or above v, 
+ *or both at or below v. In addition, at least one of the ajacent verteces is
+ *strictly below or above v. 
+ * A vertex is a relex vertex if the internals angle is strictly greater than 
+ *180. In other words, if the the signed area is negative:
+ *(x1, y1), (x2, y2), (x3, y3) are the three vertices along a polygon, the 
+ *order is such that left hand side is inside the polygon. Then (x2,y2) is
+ *reflex if: 
+ *  (x2-x1, y2-y1) cross (x3-x1, y3-y1) <0.
+ *A vertex is an interior cusp if it is a cusp and a reflex.
+ *A vertex is an exterior cusp if it is a cusp but not a reflex.
+ *
+ */
+
+#ifndef _PARTITIONY_H
+#define _PARTITIONY_H
+
+#include "directedLine.h"
+
+/*whether an edge is below a vertex*/
+Int isBelow(directedLine *v, directedLine *e);
+
+/*whether an edge is above a vertex*/
+Int isAbove(directedLine *v, directedLine *e);
+
+/*not-cusp,
+ *inerior cusp
+ *exterior cusp
+ */
+Int cuspType(directedLine *v);
+
+/*used in trapezoidalization*/
+typedef struct sweepRange{
+  directedLine *left;
+  Int leftType; /*either a vertex (leftType=0) or an edge (leftType =1) */
+  directedLine *right;
+  Int rightType; /*either a vertex (rightType=0) or an edge (rightType =1) */  
+} sweepRange;
+
+sweepRange* sweepRangeMake(directedLine* left, Int leftType,
+			   directedLine* right, Int rightType);
+
+void sweepRangeDelete(sweepRange* range);
+Int sweepRangeEqual(sweepRange* sr1, sweepRange* sr2);
+
+/*given a set of simple polygons where the interior 
+ *is decided by left-hand principle,
+ *return a range (sight) for each vertex. This is called
+ *Trapezoidalization.
+ */
+void sweepY(Int nVertices, directedLine **sortedVerteces, sweepRange** ret_ranges);
+
+
+directedLine* partitionY(directedLine *polygons, sampledLine **retSampledLines);
+
+void findDiagonals(Int total_num_edges, directedLine** sortedVertices, sweepRange** ranges, Int& num_diagonals, directedLine** diagonal_vertices);
+
+directedLine** DBGfindDiagonals(directedLine *polygons, Int& num_diagonals);
+
+#endif
-- 
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