dali-physics/third-party/bullet3/src/Bullet3Geometry/b3GeometryUtil.cpp

   1 /*
   2 Copyright (c) 2003-2006 Gino van den Bergen / Erwin Coumans  https://bulletphysics.org
   3
   4 This software is provided 'as-is', without any express or implied warranty.
   5 In no event will the authors be held liable for any damages arising from the use of this software.
   6 Permission is granted to anyone to use this software for any purpose,
   7 including commercial applications, and to alter it and redistribute it freely,
   8 subject to the following restrictions:
   9
  10 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
  11 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
  12 3. This notice may not be removed or altered from any source distribution.
  13 */
  14
  15 #include "b3GeometryUtil.h"
  16
  17 /*
  18   Make sure this dummy function never changes so that it
  19   can be used by probes that are checking whether the
  20   library is actually installed.
  21 */
  22 extern "C"
  23 {
  24         void b3BulletMathProbe();
  25
  26         void b3BulletMathProbe() {}
  27 }
  28
  29 bool b3GeometryUtil::isPointInsidePlanes(const b3AlignedObjectArray<b3Vector3>& planeEquations, const b3Vector3& point, b3Scalar margin)
  30 {
  31         int numbrushes = planeEquations.size();
  32         for (int i = 0; i < numbrushes; i++)
  33         {
  34                 const b3Vector3& N1 = planeEquations[i];
  35                 b3Scalar dist = b3Scalar(N1.dot(point)) + b3Scalar(N1[3]) - margin;
  36                 if (dist > b3Scalar(0.))
  37                 {
  38                         return false;
  39                 }
  40         }
  41         return true;
  42 }
  43
  44 bool b3GeometryUtil::areVerticesBehindPlane(const b3Vector3& planeNormal, const b3AlignedObjectArray<b3Vector3>& vertices, b3Scalar margin)
  45 {
  46         int numvertices = vertices.size();
  47         for (int i = 0; i < numvertices; i++)
  48         {
  49                 const b3Vector3& N1 = vertices[i];
  50                 b3Scalar dist = b3Scalar(planeNormal.dot(N1)) + b3Scalar(planeNormal[3]) - margin;
  51                 if (dist > b3Scalar(0.))
  52                 {
  53                         return false;
  54                 }
  55         }
  56         return true;
  57 }
  58
  59 bool notExist(const b3Vector3& planeEquation, const b3AlignedObjectArray<b3Vector3>& planeEquations);
  60
  61 bool notExist(const b3Vector3& planeEquation, const b3AlignedObjectArray<b3Vector3>& planeEquations)
  62 {
  63         int numbrushes = planeEquations.size();
  64         for (int i = 0; i < numbrushes; i++)
  65         {
  66                 const b3Vector3& N1 = planeEquations[i];
  67                 if (planeEquation.dot(N1) > b3Scalar(0.999))
  68                 {
  69                         return false;
  70                 }
  71         }
  72         return true;
  73 }
  74
  75 void b3GeometryUtil::getPlaneEquationsFromVertices(b3AlignedObjectArray<b3Vector3>& vertices, b3AlignedObjectArray<b3Vector3>& planeEquationsOut)
  76 {
  77         const int numvertices = vertices.size();
  78         // brute force:
  79         for (int i = 0; i < numvertices; i++)
  80         {
  81                 const b3Vector3& N1 = vertices[i];
  82
  83                 for (int j = i + 1; j < numvertices; j++)
  84                 {
  85                         const b3Vector3& N2 = vertices[j];
  86
  87                         for (int k = j + 1; k < numvertices; k++)
  88                         {
  89                                 const b3Vector3& N3 = vertices[k];
  90
  91                                 b3Vector3 planeEquation, edge0, edge1;
  92                                 edge0 = N2 - N1;
  93                                 edge1 = N3 - N1;
  94                                 b3Scalar normalSign = b3Scalar(1.);
  95                                 for (int ww = 0; ww < 2; ww++)
  96                                 {
  97                                         planeEquation = normalSign * edge0.cross(edge1);
  98                                         if (planeEquation.length2() > b3Scalar(0.0001))
  99                                         {
 100                                                 planeEquation.normalize();
 101                                                 if (notExist(planeEquation, planeEquationsOut))
 102                                                 {
 103                                                         planeEquation[3] = -planeEquation.dot(N1);
 104
 105                                                         //check if inside, and replace supportingVertexOut if needed
 106                                                         if (areVerticesBehindPlane(planeEquation, vertices, b3Scalar(0.01)))
 107                                                         {
 108                                                                 planeEquationsOut.push_back(planeEquation);
 109                                                         }
 110                                                 }
 111                                         }
 112                                         normalSign = b3Scalar(-1.);
 113                                 }
 114                         }
 115                 }
 116         }
 117 }
 118
 119 void b3GeometryUtil::getVerticesFromPlaneEquations(const b3AlignedObjectArray<b3Vector3>& planeEquations, b3AlignedObjectArray<b3Vector3>& verticesOut)
 120 {
 121         const int numbrushes = planeEquations.size();
 122         // brute force:
 123         for (int i = 0; i < numbrushes; i++)
 124         {
 125                 const b3Vector3& N1 = planeEquations[i];
 126
 127                 for (int j = i + 1; j < numbrushes; j++)
 128                 {
 129                         const b3Vector3& N2 = planeEquations[j];
 130
 131                         for (int k = j + 1; k < numbrushes; k++)
 132                         {
 133                                 const b3Vector3& N3 = planeEquations[k];
 134
 135                                 b3Vector3 n2n3;
 136                                 n2n3 = N2.cross(N3);
 137                                 b3Vector3 n3n1;
 138                                 n3n1 = N3.cross(N1);
 139                                 b3Vector3 n1n2;
 140                                 n1n2 = N1.cross(N2);
 141
 142                                 if ((n2n3.length2() > b3Scalar(0.0001)) &&
 143                                         (n3n1.length2() > b3Scalar(0.0001)) &&
 144                                         (n1n2.length2() > b3Scalar(0.0001)))
 145                                 {
 146                                         //point P out of 3 plane equations:
 147
 148                                         //      d1 ( N2 * N3 ) + d2 ( N3 * N1 ) + d3 ( N1 * N2 )
 149                                         //P =  -------------------------------------------------------------------------
 150                                         //   N1 . ( N2 * N3 )
 151
 152                                         b3Scalar quotient = (N1.dot(n2n3));
 153                                         if (b3Fabs(quotient) > b3Scalar(0.000001))
 154                                         {
 155                                                 quotient = b3Scalar(-1.) / quotient;
 156                                                 n2n3 *= N1[3];
 157                                                 n3n1 *= N2[3];
 158                                                 n1n2 *= N3[3];
 159                                                 b3Vector3 potentialVertex = n2n3;
 160                                                 potentialVertex += n3n1;
 161                                                 potentialVertex += n1n2;
 162                                                 potentialVertex *= quotient;
 163
 164                                                 //check if inside, and replace supportingVertexOut if needed
 165                                                 if (isPointInsidePlanes(planeEquations, potentialVertex, b3Scalar(0.01)))
 166                                                 {
 167                                                         verticesOut.push_back(potentialVertex);
 168                                                 }
 169                                         }
 170                                 }
 171                         }
 172                 }
 173         }
 174 }