axiosengine/axios/Common/Decomposition/CDT/Delaunay/DelaunayTriangle.cs
2012-03-19 18:57:59 -05:00

420 lines
13 KiB
C#

/* 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
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* 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.
*/
// Changes from the Java version
// attributification
// Future possibilities
// Flattening out the number of indirections
// Replacing arrays of 3 with fixed-length arrays?
// Replacing bool[3] with a bit array of some sort?
// Bundling everything into an AoS mess?
// Hardcode them all as ABC ?
using System;
using System.Collections.Generic;
using System.Diagnostics;
using Poly2Tri.Triangulation.Delaunay.Sweep;
using Poly2Tri.Triangulation.Util;
namespace Poly2Tri.Triangulation.Delaunay
{
public class DelaunayTriangle
{
/** Neighbor pointers */
/** Flags to determine if an edge is a Delauney edge */
public FixedBitArray3 EdgeIsConstrained;
/** Flags to determine if an edge is a Constrained edge */
public FixedBitArray3 EdgeIsDelaunay;
public FixedArray3<DelaunayTriangle> Neighbors;
/** Has this triangle been marked as an interior triangle? */
public FixedArray3<TriangulationPoint> Points;
public DelaunayTriangle(TriangulationPoint p1, TriangulationPoint p2, TriangulationPoint p3)
{
Points[0] = p1;
Points[1] = p2;
Points[2] = p3;
}
public bool IsInterior { get; set; }
public int IndexOf(TriangulationPoint p)
{
int i = Points.IndexOf(p);
if (i == -1) throw new Exception("Calling index with a point that doesn't exist in triangle");
return i;
}
//TODO: Port note - different implementation
public int IndexCW(TriangulationPoint p)
{
int index = IndexOf(p);
switch (index)
{
case 0:
return 2;
case 1:
return 0;
default:
return 1;
}
}
//TODO: Port note - different implementation
public int IndexCCW(TriangulationPoint p)
{
int index = IndexOf(p);
switch (index)
{
case 0:
return 1;
case 1:
return 2;
default:
return 0;
}
}
public bool Contains(TriangulationPoint p)
{
return (p == Points[0] || p == Points[1] || p == Points[2]);
}
public bool Contains(DTSweepConstraint e)
{
return (Contains(e.P) && Contains(e.Q));
}
public bool Contains(TriangulationPoint p, TriangulationPoint q)
{
return (Contains(p) && Contains(q));
}
/// <summary>
/// Update neighbor pointers
/// </summary>
/// <param name="p1">Point 1 of the shared edge</param>
/// <param name="p2">Point 2 of the shared edge</param>
/// <param name="t">This triangle's new neighbor</param>
private void MarkNeighbor(TriangulationPoint p1, TriangulationPoint p2, DelaunayTriangle t)
{
if ((p1 == Points[2] && p2 == Points[1]) || (p1 == Points[1] && p2 == Points[2]))
{
Neighbors[0] = t;
}
else if ((p1 == Points[0] && p2 == Points[2]) || (p1 == Points[2] && p2 == Points[0]))
{
Neighbors[1] = t;
}
else if ((p1 == Points[0] && p2 == Points[1]) || (p1 == Points[1] && p2 == Points[0]))
{
Neighbors[2] = t;
}
else
{
Debug.WriteLine("Neighbor error, please report!");
// throw new Exception("Neighbor error, please report!");
}
}
/// <summary>
/// Exhaustive search to update neighbor pointers
/// </summary>
public void MarkNeighbor(DelaunayTriangle t)
{
if (t.Contains(Points[1], Points[2]))
{
Neighbors[0] = t;
t.MarkNeighbor(Points[1], Points[2], this);
}
else if (t.Contains(Points[0], Points[2]))
{
Neighbors[1] = t;
t.MarkNeighbor(Points[0], Points[2], this);
}
else if (t.Contains(Points[0], Points[1]))
{
Neighbors[2] = t;
t.MarkNeighbor(Points[0], Points[1], this);
}
else
{
Debug.WriteLine("markNeighbor failed");
}
}
public void ClearNeighbors()
{
Neighbors[0] = Neighbors[1] = Neighbors[2] = null;
}
public void ClearNeighbor(DelaunayTriangle triangle)
{
if (Neighbors[0] == triangle)
{
Neighbors[0] = null;
}
else if (Neighbors[1] == triangle)
{
Neighbors[1] = null;
}
else
{
Neighbors[2] = null;
}
}
/**
* Clears all references to all other triangles and points
*/
public void Clear()
{
DelaunayTriangle t;
for (int i = 0; i < 3; i++)
{
t = Neighbors[i];
if (t != null)
{
t.ClearNeighbor(this);
}
}
ClearNeighbors();
Points[0] = Points[1] = Points[2] = null;
}
/// <param name="t">Opposite triangle</param>
/// <param name="p">The point in t that isn't shared between the triangles</param>
public TriangulationPoint OppositePoint(DelaunayTriangle t, TriangulationPoint p)
{
Debug.Assert(t != this, "self-pointer error");
return PointCW(t.PointCW(p));
}
public DelaunayTriangle NeighborCW(TriangulationPoint point)
{
return Neighbors[(Points.IndexOf(point) + 1)%3];
}
public DelaunayTriangle NeighborCCW(TriangulationPoint point)
{
return Neighbors[(Points.IndexOf(point) + 2)%3];
}
public DelaunayTriangle NeighborAcross(TriangulationPoint point)
{
return Neighbors[Points.IndexOf(point)];
}
public TriangulationPoint PointCCW(TriangulationPoint point)
{
return Points[(IndexOf(point) + 1)%3];
}
public TriangulationPoint PointCW(TriangulationPoint point)
{
return Points[(IndexOf(point) + 2)%3];
}
private void RotateCW()
{
var t = Points[2];
Points[2] = Points[1];
Points[1] = Points[0];
Points[0] = t;
}
/// <summary>
/// Legalize triangle by rotating clockwise around oPoint
/// </summary>
/// <param name="oPoint">The origin point to rotate around</param>
/// <param name="nPoint">???</param>
public void Legalize(TriangulationPoint oPoint, TriangulationPoint nPoint)
{
RotateCW();
Points[IndexCCW(oPoint)] = nPoint;
}
public override string ToString()
{
return Points[0] + "," + Points[1] + "," + Points[2];
}
/// <summary>
/// Finalize edge marking
/// </summary>
public void MarkNeighborEdges()
{
for (int i = 0; i < 3; i++)
if (EdgeIsConstrained[i] && Neighbors[i] != null)
{
Neighbors[i].MarkConstrainedEdge(Points[(i + 1)%3], Points[(i + 2)%3]);
}
}
public void MarkEdge(DelaunayTriangle triangle)
{
for (int i = 0; i < 3; i++)
if (EdgeIsConstrained[i])
{
triangle.MarkConstrainedEdge(Points[(i + 1)%3], Points[(i + 2)%3]);
}
}
public void MarkEdge(List<DelaunayTriangle> tList)
{
foreach (DelaunayTriangle t in tList)
for (int i = 0; i < 3; i++)
if (t.EdgeIsConstrained[i])
{
MarkConstrainedEdge(t.Points[(i + 1)%3], t.Points[(i + 2)%3]);
}
}
public void MarkConstrainedEdge(int index)
{
EdgeIsConstrained[index] = true;
}
public void MarkConstrainedEdge(DTSweepConstraint edge)
{
MarkConstrainedEdge(edge.P, edge.Q);
}
/// <summary>
/// Mark edge as constrained
/// </summary>
public void MarkConstrainedEdge(TriangulationPoint p, TriangulationPoint q)
{
int i = EdgeIndex(p, q);
if (i != -1) EdgeIsConstrained[i] = true;
}
public double Area()
{
double b = Points[0].X - Points[1].X;
double h = Points[2].Y - Points[1].Y;
return Math.Abs((b*h*0.5f));
}
public TriangulationPoint Centroid()
{
double cx = (Points[0].X + Points[1].X + Points[2].X)/3f;
double cy = (Points[0].Y + Points[1].Y + Points[2].Y)/3f;
return new TriangulationPoint(cx, cy);
}
/// <summary>
/// Get the index of the neighbor that shares this edge (or -1 if it isn't shared)
/// </summary>
/// <returns>index of the shared edge or -1 if edge isn't shared</returns>
public int EdgeIndex(TriangulationPoint p1, TriangulationPoint p2)
{
int i1 = Points.IndexOf(p1);
int i2 = Points.IndexOf(p2);
// Points of this triangle in the edge p1-p2
bool a = (i1 == 0 || i2 == 0);
bool b = (i1 == 1 || i2 == 1);
bool c = (i1 == 2 || i2 == 2);
if (b && c) return 0;
if (a && c) return 1;
if (a && b) return 2;
return -1;
}
public bool GetConstrainedEdgeCCW(TriangulationPoint p)
{
return EdgeIsConstrained[(IndexOf(p) + 2)%3];
}
public bool GetConstrainedEdgeCW(TriangulationPoint p)
{
return EdgeIsConstrained[(IndexOf(p) + 1)%3];
}
public bool GetConstrainedEdgeAcross(TriangulationPoint p)
{
return EdgeIsConstrained[IndexOf(p)];
}
public void SetConstrainedEdgeCCW(TriangulationPoint p, bool ce)
{
EdgeIsConstrained[(IndexOf(p) + 2)%3] = ce;
}
public void SetConstrainedEdgeCW(TriangulationPoint p, bool ce)
{
EdgeIsConstrained[(IndexOf(p) + 1)%3] = ce;
}
public void SetConstrainedEdgeAcross(TriangulationPoint p, bool ce)
{
EdgeIsConstrained[IndexOf(p)] = ce;
}
public bool GetDelaunayEdgeCCW(TriangulationPoint p)
{
return EdgeIsDelaunay[(IndexOf(p) + 2)%3];
}
public bool GetDelaunayEdgeCW(TriangulationPoint p)
{
return EdgeIsDelaunay[(IndexOf(p) + 1)%3];
}
public bool GetDelaunayEdgeAcross(TriangulationPoint p)
{
return EdgeIsDelaunay[IndexOf(p)];
}
public void SetDelaunayEdgeCCW(TriangulationPoint p, bool ce)
{
EdgeIsDelaunay[(IndexOf(p) + 2)%3] = ce;
}
public void SetDelaunayEdgeCW(TriangulationPoint p, bool ce)
{
EdgeIsDelaunay[(IndexOf(p) + 1)%3] = ce;
}
public void SetDelaunayEdgeAcross(TriangulationPoint p, bool ce)
{
EdgeIsDelaunay[IndexOf(p)] = ce;
}
}
}