OpenSimMirror/addon-modules/ConvexDecompositionDotNet/ConvexDecomposition.cs

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2011-05-19 20:36:01 +00:00
/* The MIT License
*
* Copyright (c) 2010 Intel Corporation.
* All rights reserved.
*
* Based on the convexdecomposition library from
* <http://codesuppository.googlecode.com> by John W. Ratcliff and Stan Melax.
*
* 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 and this permission notice 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 THE
* AUTHORS OR COPYRIGHT HOLDERS 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.
*/
using System;
using System.Collections.Generic;
using System.Diagnostics;
namespace OpenSim.Region.Physics.ConvexDecompositionDotNet
{
public delegate void ConvexDecompositionCallback(ConvexResult result);
public class FaceTri
{
public float3 P1;
public float3 P2;
public float3 P3;
public FaceTri() { }
public FaceTri(List<float3> vertices, int i1, int i2, int i3)
{
P1 = new float3(vertices[i1]);
P2 = new float3(vertices[i2]);
P3 = new float3(vertices[i3]);
}
}
public static class ConvexDecomposition
{
private static void addTri(VertexPool vl, List<int> list, float3 p1, float3 p2, float3 p3)
{
int i1 = vl.getIndex(p1);
int i2 = vl.getIndex(p2);
int i3 = vl.getIndex(p3);
// do *not* process degenerate triangles!
if ( i1 != i2 && i1 != i3 && i2 != i3 )
{
list.Add(i1);
list.Add(i2);
list.Add(i3);
}
}
public static void calcConvexDecomposition(List<float3> vertices, List<int> indices, ConvexDecompositionCallback callback, float masterVolume, int depth,
int maxDepth, float concavePercent, float mergePercent)
{
float4 plane = new float4();
bool split = false;
if (depth < maxDepth)
{
float volume = 0f;
float c = Concavity.computeConcavity(vertices, indices, ref plane, ref volume);
if (depth == 0)
{
masterVolume = volume;
}
float percent = (c * 100.0f) / masterVolume;
if (percent > concavePercent) // if great than 5% of the total volume is concave, go ahead and keep splitting.
{
split = true;
}
}
if (depth >= maxDepth || !split)
{
HullResult result = new HullResult();
HullDesc desc = new HullDesc();
desc.SetHullFlag(HullFlag.QF_TRIANGLES);
desc.Vertices = vertices;
HullError ret = HullUtils.CreateConvexHull(desc, ref result);
if (ret == HullError.QE_OK)
{
ConvexResult r = new ConvexResult(result.OutputVertices, result.Indices);
callback(r);
}
return;
}
List<int> ifront = new List<int>();
List<int> iback = new List<int>();
VertexPool vfront = new VertexPool();
VertexPool vback = new VertexPool();
// ok..now we are going to 'split' all of the input triangles against this plane!
for (int i = 0; i < indices.Count / 3; i++)
{
int i1 = indices[i * 3 + 0];
int i2 = indices[i * 3 + 1];
int i3 = indices[i * 3 + 2];
FaceTri t = new FaceTri(vertices, i1, i2, i3);
float3[] front = new float3[4];
float3[] back = new float3[4];
int fcount = 0;
int bcount = 0;
PlaneTriResult result = PlaneTri.planeTriIntersection(plane, t, 0.00001f, ref front, out fcount, ref back, out bcount);
if (fcount > 4 || bcount > 4)
{
result = PlaneTri.planeTriIntersection(plane, t, 0.00001f, ref front, out fcount, ref back, out bcount);
}
switch (result)
{
case PlaneTriResult.PTR_FRONT:
Debug.Assert(fcount == 3);
addTri(vfront, ifront, front[0], front[1], front[2]);
break;
case PlaneTriResult.PTR_BACK:
Debug.Assert(bcount == 3);
addTri(vback, iback, back[0], back[1], back[2]);
break;
case PlaneTriResult.PTR_SPLIT:
Debug.Assert(fcount >= 3 && fcount <= 4);
Debug.Assert(bcount >= 3 && bcount <= 4);
addTri(vfront, ifront, front[0], front[1], front[2]);
addTri(vback, iback, back[0], back[1], back[2]);
if (fcount == 4)
{
addTri(vfront, ifront, front[0], front[2], front[3]);
}
if (bcount == 4)
{
addTri(vback, iback, back[0], back[2], back[3]);
}
break;
}
}
// ok... here we recursively call
if (ifront.Count > 0)
{
int vcount = vfront.GetSize();
List<float3> vertices2 = vfront.GetVertices();
for (int i = 0; i < vertices2.Count; i++)
vertices2[i] = new float3(vertices2[i]);
int tcount = ifront.Count / 3;
calcConvexDecomposition(vertices2, ifront, callback, masterVolume, depth + 1, maxDepth, concavePercent, mergePercent);
}
ifront.Clear();
vfront.Clear();
if (iback.Count > 0)
{
int vcount = vback.GetSize();
List<float3> vertices2 = vback.GetVertices();
int tcount = iback.Count / 3;
calcConvexDecomposition(vertices2, iback, callback, masterVolume, depth + 1, maxDepth, concavePercent, mergePercent);
}
iback.Clear();
vback.Clear();
}
}
}