Bullet Collision Detection & Physics Library
btConvexPointCloudShape.cpp
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1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2009 Erwin Coumans http://bulletphysics.org
4 
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose,
8 including commercial applications, and to alter it and redistribute it freely,
9 subject to the following restrictions:
10 
11 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.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15 
18 
20 
22 {
23  m_localScaling = scaling;
25 }
26 
27 #ifndef __SPU__
29 {
30  btVector3 supVec(btScalar(0.), btScalar(0.), btScalar(0.));
31  btScalar maxDot = btScalar(-BT_LARGE_FLOAT);
32 
33  btVector3 vec = vec0;
34  btScalar lenSqr = vec.length2();
35  if (lenSqr < btScalar(0.0001))
36  {
37  vec.setValue(1, 0, 0);
38  }
39  else
40  {
41  btScalar rlen = btScalar(1.) / btSqrt(lenSqr);
42  vec *= rlen;
43  }
44 
45  if (m_numPoints > 0)
46  {
47  // Here we take advantage of dot(a*b, c) = dot( a, b*c) to do less work. Note this transformation is true mathematically, not numerically.
48  // btVector3 scaled = vec * m_localScaling;
49  int index = (int)vec.maxDot(&m_unscaledPoints[0], m_numPoints, maxDot); //FIXME: may violate encapsulation of m_unscaledPoints
50  return getScaledPoint(index);
51  }
52 
53  return supVec;
54 }
55 
56 void btConvexPointCloudShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors, btVector3* supportVerticesOut, int numVectors) const
57 {
58  for (int j = 0; j < numVectors; j++)
59  {
60  const btVector3& vec = vectors[j] * m_localScaling; // dot( a*c, b) = dot(a, b*c)
61  btScalar maxDot;
62  int index = (int)vec.maxDot(&m_unscaledPoints[0], m_numPoints, maxDot);
63  supportVerticesOut[j][3] = btScalar(-BT_LARGE_FLOAT);
64  if (0 <= index)
65  {
66  //WARNING: don't swap next lines, the w component would get overwritten!
67  supportVerticesOut[j] = getScaledPoint(index);
68  supportVerticesOut[j][3] = maxDot;
69  }
70  }
71 }
72 
74 {
76 
77  if (getMargin() != btScalar(0.))
78  {
79  btVector3 vecnorm = vec;
80  if (vecnorm.length2() < (SIMD_EPSILON * SIMD_EPSILON))
81  {
82  vecnorm.setValue(btScalar(-1.), btScalar(-1.), btScalar(-1.));
83  }
84  vecnorm.normalize();
85  supVertex += getMargin() * vecnorm;
86  }
87  return supVertex;
88 }
89 
90 #endif
91 
92 //currently just for debugging (drawing), perhaps future support for algebraic continuous collision detection
93 //Please note that you can debug-draw btConvexHullShape with the Raytracer Demo
95 {
96  return m_numPoints;
97 }
98 
100 {
101  return 0;
102 }
103 
105 {
106  btAssert(0);
107 }
108 
110 {
111  vtx = m_unscaledPoints[i] * m_localScaling;
112 }
113 
115 {
116  return 0;
117 }
118 
120 {
121  btAssert(0);
122 }
123 
124 //not yet
126 {
127  btAssert(0);
128  return false;
129 }
#define SIMD_EPSILON
Definition: btScalar.h:523
btVector3 getScaledPoint(int index) const
#define BT_LARGE_FLOAT
Definition: btScalar.h:296
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition: btVector3.h:640
virtual void getEdge(int i, btVector3 &pa, btVector3 &pb) const
btScalar length2() const
Return the length of the vector squared.
Definition: btVector3.h:251
btScalar btSqrt(btScalar y)
Definition: btScalar.h:446
#define btAssert(x)
Definition: btScalar.h:133
virtual void setLocalScaling(const btVector3 &scaling)
in case we receive negative scaling
virtual void batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3 *vectors, btVector3 *supportVerticesOut, int numVectors) const
btVector3 & normalize()
Normalize this vector x^2 + y^2 + z^2 = 1.
Definition: btVector3.h:303
long maxDot(const btVector3 *array, long array_count, btScalar &dotOut) const
returns index of maximum dot product between this and vectors in array[]
Definition: btVector3.h:998
virtual void getVertex(int i, btVector3 &vtx) const
virtual void getPlane(btVector3 &planeNormal, btVector3 &planeSupport, int i) const
virtual btScalar getMargin() const
virtual bool isInside(const btVector3 &pt, btScalar tolerance) const
virtual int getNumVertices() const
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:80
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const
virtual btVector3 localGetSupportingVertexWithoutMargin(const btVector3 &vec) const
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:294