feat: Initial commit

Assets/Plugins/Poly2Tri/Triangulation/TriangulationConstraint.cs

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+/* Poly2Tri
+ * Copyright (c) 2009-2010, Poly2Tri Contributors
+ * http://code.google.com/p/poly2tri/
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * * Neither the name of Poly2Tri nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without specific
+ *   prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+/**
+ * Forces a triangle edge between two points p and q
+ * when triangulating. For example used to enforce
+ * Polygon Edges during a polygon triangulation.
+ * 
+ * @author Thomas Åhlén, thahlen@gmail.com
+ */
+
+using System;
+
+
+namespace Poly2Tri
+{
+    public class Edge
+    {
+        protected Point2D mP = null;
+        protected Point2D mQ = null;
+
+        public Point2D EdgeStart { get { return mP; } set { mP= value;} }
+        public Point2D EdgeEnd { get { return mQ; } set { mQ = value; } }
+
+        public Edge() { mP = null; mQ = null; }
+        public Edge(Point2D edgeStart, Point2D edgeEnd)
+        {
+            mP = edgeStart;
+            mQ = edgeEnd;
+        }
+    }
+
+ 
+    public class TriangulationConstraint : Edge
+    {
+        private uint mContraintCode = 0;
+
+        public TriangulationPoint P
+        {
+            get { return mP as TriangulationPoint; } 
+            set 
+            {
+                // Note:  intentionally use != instead of !Equals() because we
+                // WANT to compare pointer values here rather than VertexCode values
+                if (value != null && mP != value)
+                {
+                    mP = value;
+                    CalculateContraintCode();
+                }
+            }
+        }
+        public TriangulationPoint Q
+        {
+            get { return mQ as TriangulationPoint; }
+            set
+            {
+                // Note:  intentionally use != instead of !Equals() because we
+                // WANT to compare pointer values here rather than VertexCode values
+                if (value != null && mQ != value)
+                {
+                    mQ = value;
+                    CalculateContraintCode();
+                }
+            }
+        }
+        public uint ConstraintCode { get { return mContraintCode; } }
+
+
+        /// <summary>
+        /// Give two points in any order. Will always be ordered so
+        /// that q.y > p.y and q.x > p.x if same y value 
+        /// </summary>
+        public TriangulationConstraint(TriangulationPoint p1, TriangulationPoint p2)
+        {
+            mP = p1;
+            mQ = p2;
+            if (p1.Y > p2.Y)
+            {
+                mQ = p1;
+                mP = p2;
+            }
+            else if (p1.Y == p2.Y)
+            {
+                if (p1.X > p2.X)
+                {
+                    mQ = p1;
+                    mP = p2;
+                }
+                else if (p1.X == p2.X)
+                {
+                    //                logger.info( "Failed to create constraint {}={}", p1, p2 );
+                    //                throw new DuplicatePointException( p1 + "=" + p2 );
+                    //                return;
+                }
+            }
+            CalculateContraintCode();
+        }
+
+
+        public override string ToString()
+        {
+            return "[P=" + P.ToString() + ", Q=" + Q.ToString() + " : {" + mContraintCode.ToString() + "}]";
+        }
+
+        
+        public void CalculateContraintCode()
+        {
+            mContraintCode = TriangulationConstraint.CalculateContraintCode(P, Q);
+        }
+
+
+        public static uint CalculateContraintCode(TriangulationPoint p, TriangulationPoint q)
+        {
+            if (p == null || p == null)
+            {
+                throw new ArgumentNullException();
+            }
+
+            uint constraintCode = MathUtil.Jenkins32Hash(BitConverter.GetBytes(p.VertexCode), 0);
+            constraintCode = MathUtil.Jenkins32Hash(BitConverter.GetBytes(q.VertexCode), constraintCode);
+
+            return constraintCode;
+        }
+
+    }
+}