448 lines
14 KiB
C#
448 lines
14 KiB
C#
/* Poly2Tri
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* Copyright (c) 2009-2010, Poly2Tri Contributors
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* http://code.google.com/p/poly2tri/
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*
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* * Neither the name of Poly2Tri nor the names of its contributors may be
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* used to endorse or promote products derived from this software without specific
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* prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/// Changes from the Java version
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/// attributification
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/// Future possibilities
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/// Flattening out the number of indirections
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/// Replacing arrays of 3 with fixed-length arrays?
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/// Replacing bool[3] with a bit array of some sort?
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/// Bundling everything into an AoS mess?
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/// Hardcode them all as ABC ?
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using System;
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using System.Diagnostics;
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using System.Collections.Generic;
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namespace Poly2Tri
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{
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public class DelaunayTriangle
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{
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public FixedArray3<TriangulationPoint> Points;
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public FixedArray3<DelaunayTriangle> Neighbors;
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private FixedBitArray3 mEdgeIsConstrained;
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public FixedBitArray3 EdgeIsConstrained { get { return mEdgeIsConstrained; } }
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public FixedBitArray3 EdgeIsDelaunay;
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public bool IsInterior { get; set; }
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public DelaunayTriangle(TriangulationPoint p1, TriangulationPoint p2, TriangulationPoint p3)
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{
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Points[0] = p1;
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Points[1] = p2;
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Points[2] = p3;
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}
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public int IndexOf(TriangulationPoint p)
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{
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int i = Points.IndexOf(p);
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if (i == -1)
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{
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throw new Exception("Calling index with a point that doesn't exist in triangle");
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}
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return i;
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}
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public int IndexCWFrom(TriangulationPoint p)
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{
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return (IndexOf(p) + 2) % 3;
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}
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public int IndexCCWFrom(TriangulationPoint p)
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{
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return (IndexOf(p) + 1) % 3;
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}
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public bool Contains(TriangulationPoint p)
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{
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return Points.Contains(p);
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}
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/// <summary>
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/// Update neighbor pointers
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/// </summary>
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/// <param name="p1">Point 1 of the shared edge</param>
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/// <param name="p2">Point 2 of the shared edge</param>
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/// <param name="t">This triangle's new neighbor</param>
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private void MarkNeighbor(TriangulationPoint p1, TriangulationPoint p2, DelaunayTriangle t)
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{
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int i = EdgeIndex(p1, p2);
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if (i == -1)
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{
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throw new Exception("Error marking neighbors -- t doesn't contain edge p1-p2!");
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}
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Neighbors[i] = t;
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}
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/// <summary>
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/// Exhaustive search to update neighbor pointers
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/// </summary>
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public void MarkNeighbor(DelaunayTriangle t)
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{
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// Points of this triangle also belonging to t
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bool a = t.Contains(Points[0]);
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bool b = t.Contains(Points[1]);
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bool c = t.Contains(Points[2]);
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if (b && c)
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{
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Neighbors[0] = t;
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t.MarkNeighbor(Points[1], Points[2], this);
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}
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else if (a && c)
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{
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Neighbors[1] = t;
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t.MarkNeighbor(Points[0], Points[2], this);
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}
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else if (a && b)
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{
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Neighbors[2] = t;
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t.MarkNeighbor(Points[0], Points[1], this);
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}
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else
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{
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throw new Exception("Failed to mark neighbor, doesn't share an edge!");
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}
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}
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public void ClearNeighbors()
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{
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Neighbors[0] = Neighbors[1] = Neighbors[2] = null;
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}
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public void ClearNeighbor(DelaunayTriangle triangle)
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{
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if (Neighbors[0] == triangle)
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{
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Neighbors[0] = null;
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}
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else if (Neighbors[1] == triangle)
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{
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Neighbors[1] = null;
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}
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else if( Neighbors[2] == triangle)
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{
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Neighbors[2] = null;
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}
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}
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/// <summary>
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/// Clears all references to all other triangles and points
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/// </summary>
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public void Clear()
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{
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DelaunayTriangle t;
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for (int i = 0; i < 3; i++)
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{
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t = Neighbors[i];
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if (t != null)
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{
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t.ClearNeighbor(this);
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}
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}
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ClearNeighbors();
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Points[0] = Points[1] = Points[2] = null;
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}
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/// <param name="t">Opposite triangle</param>
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/// <param name="p">The point in t that isn't shared between the triangles</param>
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public TriangulationPoint OppositePoint(DelaunayTriangle t, TriangulationPoint p)
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{
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Debug.Assert(t != this, "self-pointer error");
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return PointCWFrom(t.PointCWFrom(p));
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}
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public DelaunayTriangle NeighborCWFrom(TriangulationPoint point)
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{
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return Neighbors[(Points.IndexOf(point) + 1) % 3];
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}
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public DelaunayTriangle NeighborCCWFrom(TriangulationPoint point)
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{
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return Neighbors[(Points.IndexOf(point) + 2) % 3];
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}
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public DelaunayTriangle NeighborAcrossFrom(TriangulationPoint point)
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{
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return Neighbors[Points.IndexOf(point)];
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}
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public TriangulationPoint PointCCWFrom(TriangulationPoint point)
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{
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return Points[(IndexOf(point) + 1) % 3];
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}
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public TriangulationPoint PointCWFrom(TriangulationPoint point)
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{
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return Points[(IndexOf(point) + 2) % 3];
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}
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private void RotateCW()
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{
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var t = Points[2];
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Points[2] = Points[1];
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Points[1] = Points[0];
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Points[0] = t;
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}
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/// <summary>
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/// Legalize triangle by rotating clockwise around oPoint
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/// </summary>
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/// <param name="oPoint">The origin point to rotate around</param>
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/// <param name="nPoint">???</param>
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public void Legalize(TriangulationPoint oPoint, TriangulationPoint nPoint)
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{
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RotateCW();
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Points[IndexCCWFrom(oPoint)] = nPoint;
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}
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public override string ToString()
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{
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return Points[0] + "," + Points[1] + "," + Points[2];
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}
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/// <summary>
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/// Finalize edge marking
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/// </summary>
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public void MarkNeighborEdges()
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{
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for (int i = 0; i < 3; i++)
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{
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if (EdgeIsConstrained[i] && Neighbors[i] != null)
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{
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Neighbors[i].MarkConstrainedEdge(Points[(i + 1) % 3], Points[(i + 2) % 3]);
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}
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}
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}
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public void MarkEdge(DelaunayTriangle triangle)
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{
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for (int i = 0; i < 3; i++) if (EdgeIsConstrained[i])
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{
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triangle.MarkConstrainedEdge(Points[(i + 1) % 3], Points[(i + 2) % 3]);
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}
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}
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public void MarkEdge(List<DelaunayTriangle> tList)
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{
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foreach (DelaunayTriangle t in tList)
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{
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for (int i = 0; i < 3; i++)
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{
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if (t.EdgeIsConstrained[i])
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{
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MarkConstrainedEdge(t.Points[(i + 1) % 3], t.Points[(i + 2) % 3]);
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}
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}
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}
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}
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public void MarkConstrainedEdge(int index)
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{
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mEdgeIsConstrained[index] = true;
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}
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public void MarkConstrainedEdge(DTSweepConstraint edge)
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{
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MarkConstrainedEdge(edge.P, edge.Q);
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}
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/// <summary>
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/// Mark edge as constrained
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/// </summary>
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public void MarkConstrainedEdge(TriangulationPoint p, TriangulationPoint q)
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{
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int i = EdgeIndex(p, q);
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if (i != -1)
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{
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mEdgeIsConstrained[i] = true;
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}
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}
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public double Area()
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{
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double b = Points[0].X - Points[1].X;
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double h = Points[2].Y - Points[1].Y;
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return Math.Abs((b * h * 0.5f));
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}
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public TriangulationPoint Centroid()
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{
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double cx = (Points[0].X + Points[1].X + Points[2].X) / 3f;
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double cy = (Points[0].Y + Points[1].Y + Points[2].Y) / 3f;
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return new TriangulationPoint(cx, cy);
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}
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/// <summary>
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/// Get the index of the neighbor that shares this edge (or -1 if it isn't shared)
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/// </summary>
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/// <returns>index of the shared edge or -1 if edge isn't shared</returns>
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public int EdgeIndex(TriangulationPoint p1, TriangulationPoint p2)
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{
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int i1 = Points.IndexOf(p1);
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int i2 = Points.IndexOf(p2);
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// Points of this triangle in the edge p1-p2
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bool a = (i1 == 0 || i2 == 0);
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bool b = (i1 == 1 || i2 == 1);
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bool c = (i1 == 2 || i2 == 2);
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if (b && c)
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{
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return 0;
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}
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if (a && c)
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{
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return 1;
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}
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if (a && b)
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{
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return 2;
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}
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return -1;
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}
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public bool GetConstrainedEdgeCCW(TriangulationPoint p) { return EdgeIsConstrained[(IndexOf(p) + 2) % 3]; }
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public bool GetConstrainedEdgeCW(TriangulationPoint p) { return EdgeIsConstrained[(IndexOf(p) + 1) % 3]; }
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public bool GetConstrainedEdgeAcross(TriangulationPoint p) { return EdgeIsConstrained[IndexOf(p)]; }
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protected void SetConstrainedEdge(int idx, bool ce)
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{
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//if (ce == false && EdgeIsConstrained[idx])
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//{
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// DTSweepConstraint edge = null;
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// if (GetEdge(idx, out edge))
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// {
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// Console.WriteLine("Removing pre-defined constraint from edge " + edge.ToString());
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// }
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//}
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mEdgeIsConstrained[idx] = ce;
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}
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public void SetConstrainedEdgeCCW(TriangulationPoint p, bool ce)
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{
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int idx = (IndexOf(p) + 2) % 3;
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SetConstrainedEdge(idx, ce);
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}
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public void SetConstrainedEdgeCW(TriangulationPoint p, bool ce)
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{
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int idx = (IndexOf(p) + 1) % 3;
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SetConstrainedEdge(idx, ce);
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}
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public void SetConstrainedEdgeAcross(TriangulationPoint p, bool ce)
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{
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int idx = IndexOf(p);
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SetConstrainedEdge(idx, ce);
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}
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public bool GetDelaunayEdgeCCW(TriangulationPoint p) { return EdgeIsDelaunay[(IndexOf(p) + 2) % 3]; }
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public bool GetDelaunayEdgeCW(TriangulationPoint p) { return EdgeIsDelaunay[(IndexOf(p) + 1) % 3]; }
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public bool GetDelaunayEdgeAcross(TriangulationPoint p) { return EdgeIsDelaunay[IndexOf(p)]; }
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public void SetDelaunayEdgeCCW(TriangulationPoint p, bool ce) { EdgeIsDelaunay[(IndexOf(p) + 2) % 3] = ce; }
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public void SetDelaunayEdgeCW(TriangulationPoint p, bool ce) { EdgeIsDelaunay[(IndexOf(p) + 1) % 3] = ce; }
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public void SetDelaunayEdgeAcross(TriangulationPoint p, bool ce) { EdgeIsDelaunay[IndexOf(p)] = ce; }
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public bool GetEdge(int idx, out DTSweepConstraint edge)
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{
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edge = null;
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if (idx < 0 || idx > 2)
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{
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return false;
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}
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TriangulationPoint p1 = Points[(idx + 1) % 3];
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TriangulationPoint p2 = Points[(idx + 2) % 3];
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if (p1.GetEdge(p2, out edge))
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{
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return true;
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}
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else if (p2.GetEdge(p1, out edge))
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{
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return true;
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}
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return false;
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}
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public bool GetEdgeCCW(TriangulationPoint p, out DTSweepConstraint edge)
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{
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int pointIndex = IndexOf(p);
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int edgeIdx = (pointIndex + 2)%3;
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return GetEdge(edgeIdx, out edge);
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}
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public bool GetEdgeCW(TriangulationPoint p, out DTSweepConstraint edge)
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{
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int pointIndex = IndexOf(p);
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int edgeIdx = (pointIndex + 1) % 3;
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return GetEdge(edgeIdx, out edge);
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}
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public bool GetEdgeAcross(TriangulationPoint p, out DTSweepConstraint edge)
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{
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int pointIndex = IndexOf(p);
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int edgeIdx = pointIndex;
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return GetEdge(edgeIdx, out edge);
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}
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}
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}
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