Bullet Collision Detection & Physics Library: btConvexHullShape.cpp Source File

Bullet Collision Detection & Physics Library

btConvexHullShape.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
16 #if defined(_WIN32) || defined(__i386__)
17 #define BT_USE_SSE_IN_API
18 #endif
19
20 #include "btConvexHullShape.h"
21 #include "BulletCollision/CollisionShapes/btCollisionMargin.h"
22
23 #include "LinearMath/btQuaternion.h"
24 #include "LinearMath/btSerializer.h"
25 #include "btConvexPolyhedron.h"
26 #include "LinearMath/btConvexHullComputer.h"
27
28 btConvexHullShape ::btConvexHullShape(const btScalar* points, int numPoints, int stride) : btPolyhedralConvexAabbCachingShape()
29 {
30 m_shapeType = CONVEX_HULL_SHAPE_PROXYTYPE;
31 m_unscaledPoints.resize(numPoints);
32
33 unsigned char* pointsAddress = (unsigned char*)points;
34
35 for (int i = 0; i < numPoints; i++)
36 {
37 btScalar* point = (btScalar*)pointsAddress;
38 m_unscaledPoints[i] = btVector3(point[0], point[1], point[2]);
39 pointsAddress += stride;
40 }
41
42 recalcLocalAabb();
43 }
44
45 void btConvexHullShape::setLocalScaling(const btVector3& scaling)
46 {
47 m_localScaling = scaling;
48 recalcLocalAabb();
49 }
50
51 void btConvexHullShape::addPoint(const btVector3& point, bool recalculateLocalAabb)
52 {
53 m_unscaledPoints.push_back(point);
54 if (recalculateLocalAabb)
55 recalcLocalAabb();
56 }
57
58 btVector3 btConvexHullShape::localGetSupportingVertexWithoutMargin(const btVector3& vec) const
59 {
60 btVector3 supVec(btScalar(0.), btScalar(0.), btScalar(0.));
61 btScalar maxDot = btScalar(-BT_LARGE_FLOAT);
62
63 // Here we take advantage of dot(a, b*c) = dot(a*b, c). Note: This is true mathematically, but not numerically.
64 if (0 < m_unscaledPoints.size())
65 {
66 btVector3 scaled = vec * m_localScaling;
67 int index = (int)scaled.maxDot(&m_unscaledPoints[0], m_unscaledPoints.size(), maxDot); // FIXME: may violate encapsulation of m_unscaledPoints
68 return m_unscaledPoints[index] * m_localScaling;
69 }
70
71 return supVec;
72 }
73
74 void btConvexHullShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors, btVector3* supportVerticesOut, int numVectors) const
75 {
76 btScalar newDot;
77 //use 'w' component of supportVerticesOut?
78 {
79 for (int i = 0; i < numVectors; i++)
80 {
81 supportVerticesOut[i][3] = btScalar(-BT_LARGE_FLOAT);
82 }
83 }
84
85 for (int j = 0; j < numVectors; j++)
86 {
87 btVector3 vec = vectors[j] * m_localScaling; // dot(a*b,c) = dot(a,b*c)
88 if (0 < m_unscaledPoints.size())
89 {
90 int i = (int)vec.maxDot(&m_unscaledPoints[0], m_unscaledPoints.size(), newDot);
91 supportVerticesOut[j] = getScaledPoint(i);
92 supportVerticesOut[j][3] = newDot;
93 }
94 else
95 supportVerticesOut[j][3] = -BT_LARGE_FLOAT;
96 }
97 }
98
99 btVector3 btConvexHullShape::localGetSupportingVertex(const btVector3& vec) const
100 {
101 btVector3 supVertex = localGetSupportingVertexWithoutMargin(vec);
102
103 if (getMargin() != btScalar(0.))
104 {
105 btVector3 vecnorm = vec;
106 if (vecnorm.length2() < (SIMD_EPSILON * SIMD_EPSILON))
107 {
108 vecnorm.setValue(btScalar(-1.), btScalar(-1.), btScalar(-1.));
109 }
110 vecnorm.normalize();
111 supVertex += getMargin() * vecnorm;
112 }
113 return supVertex;
114 }
115
116 void btConvexHullShape::optimizeConvexHull()
117 {
118 btConvexHullComputer conv;
119 conv.compute(&m_unscaledPoints[0].getX(), sizeof(btVector3), m_unscaledPoints.size(), 0.f, 0.f);
120 int numVerts = conv.vertices.size();
121 m_unscaledPoints.resize(0);
122 for (int i = 0; i < numVerts; i++)
123 {
124 m_unscaledPoints.push_back(conv.vertices[i]);
125 }
126 }
127
128 //currently just for debugging (drawing), perhaps future support for algebraic continuous collision detection
129 //Please note that you can debug-draw btConvexHullShape with the Raytracer Demo
130 int btConvexHullShape::getNumVertices() const
131 {
132 return m_unscaledPoints.size();
133 }
134
135 int btConvexHullShape::getNumEdges() const
136 {
137 return m_unscaledPoints.size();
138 }
139
140 void btConvexHullShape::getEdge(int i, btVector3& pa, btVector3& pb) const
141 {
142 int index0 = i % m_unscaledPoints.size();
143 int index1 = (i + 1) % m_unscaledPoints.size();
144 pa = getScaledPoint(index0);
145 pb = getScaledPoint(index1);
146 }
147
148 void btConvexHullShape::getVertex(int i, btVector3& vtx) const
149 {
150 vtx = getScaledPoint(i);
151 }
152
153 int btConvexHullShape::getNumPlanes() const
154 {
155 return 0;
156 }
157
158 void btConvexHullShape::getPlane(btVector3&, btVector3&, int) const
159 {
160 btAssert(0);
161 }
162
163 //not yet
164 bool btConvexHullShape::isInside(const btVector3&, btScalar) const
165 {
166 btAssert(0);
167 return false;
168 }
169
171 const char* btConvexHullShape::serialize(void* dataBuffer, btSerializer* serializer) const
172 {
173 //int szc = sizeof(btConvexHullShapeData);
174 btConvexHullShapeData* shapeData = (btConvexHullShapeData*)dataBuffer;
175 btConvexInternalShape::serialize(&shapeData->m_convexInternalShapeData, serializer);
176
177 int numElem = m_unscaledPoints.size();
178 shapeData->m_numUnscaledPoints = numElem;
179 #ifdef BT_USE_DOUBLE_PRECISION
180 shapeData->m_unscaledPointsFloatPtr = 0;
181 shapeData->m_unscaledPointsDoublePtr = numElem ? (btVector3Data*)serializer->getUniquePointer((void*)&m_unscaledPoints[0]) : 0;
182 #else
183 shapeData->m_unscaledPointsFloatPtr = numElem ? (btVector3Data*)serializer->getUniquePointer((void*)&m_unscaledPoints[0]) : 0;
184 shapeData->m_unscaledPointsDoublePtr = 0;
185 #endif
186
187 if (numElem)
188 {
189 int sz = sizeof(btVector3Data);
190 // int sz2 = sizeof(btVector3DoubleData);
191 // int sz3 = sizeof(btVector3FloatData);
192 btChunk* chunk = serializer->allocate(sz, numElem);
193 btVector3Data* memPtr = (btVector3Data*)chunk->m_oldPtr;
194 for (int i = 0; i < numElem; i++, memPtr++)
195 {
196 m_unscaledPoints[i].serialize(*memPtr);
197 }
198 serializer->finalizeChunk(chunk, btVector3DataName, BT_ARRAY_CODE, (void*)&m_unscaledPoints[0]);
199 }
200
201 // Fill padding with zeros to appease msan.
202 memset(shapeData->m_padding3, 0, sizeof(shapeData->m_padding3));
203
204 return "btConvexHullShapeData";
205 }
206
207 void btConvexHullShape::project(const btTransform& trans, const btVector3& dir, btScalar& minProj, btScalar& maxProj, btVector3& witnesPtMin, btVector3& witnesPtMax) const
208 {
209 #if 1
210 minProj = FLT_MAX;
211 maxProj = -FLT_MAX;
212
213 int numVerts = m_unscaledPoints.size();
214 for (int i = 0; i < numVerts; i++)
215 {
216 btVector3 vtx = m_unscaledPoints[i] * m_localScaling;
217 btVector3 pt = trans * vtx;
218 btScalar dp = pt.dot(dir);
219 if (dp < minProj)
220 {
221 minProj = dp;
222 witnesPtMin = pt;
223 }
224 if (dp > maxProj)
225 {
226 maxProj = dp;
227 witnesPtMax = pt;
228 }
229 }
230 #else
231 btVector3 localAxis = dir * trans.getBasis();
232 witnesPtMin = trans(localGetSupportingVertex(localAxis));
233 witnesPtMax = trans(localGetSupportingVertex(-localAxis));
234
235 minProj = witnesPtMin.dot(dir);
236 maxProj = witnesPtMax.dot(dir);
237 #endif
238
239 if (minProj > maxProj)
240 {
241 btSwap(minProj, maxProj);
242 btSwap(witnesPtMin, witnesPtMax);
243 }
244 }
btConvexHullShape::isInside
virtual bool isInside(const btVector3 &pt, btScalar tolerance) const
Definition: btConvexHullShape.cpp:164
SIMD_EPSILON
#define SIMD_EPSILON
Definition: btScalar.h:523
btConvexHullShape::getNumEdges
virtual int getNumEdges() const
Definition: btConvexHullShape.cpp:135
btAlignedObjectArray::push_back
void push_back(const T &_Val)
Definition: btAlignedObjectArray.h:264
BT_LARGE_FLOAT
#define BT_LARGE_FLOAT
Definition: btScalar.h:296
btChunk
Definition: btSerializer.h:47
btVector3::setValue
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition: btVector3.h:640
btVector3::length2
btScalar length2() const
Return the length of the vector squared.
Definition: btVector3.h:251
btConvexHullShape::getPlane
virtual void getPlane(btVector3 &planeNormal, btVector3 &planeSupport, int i) const
Definition: btConvexHullShape.cpp:158
btSerializer::getUniquePointer
virtual void * getUniquePointer(void *oldPtr)=0
btConvexHullShapeData::m_convexInternalShapeData
btConvexInternalShapeData m_convexInternalShapeData
Definition: btConvexHullShape.h:99
btConvexHullShape::project
virtual void project(const btTransform &trans, const btVector3 &dir, btScalar &minProj, btScalar &maxProj, btVector3 &witnesPtMin, btVector3 &witnesPtMax) const
Definition: btConvexHullShape.cpp:207
btConvexHullShapeData::m_unscaledPointsDoublePtr
btVector3DoubleData * m_unscaledPointsDoublePtr
Definition: btConvexHullShape.h:102
btConvexHullShape::getEdge
virtual void getEdge(int i, btVector3 &pa, btVector3 &pb) const
Definition: btConvexHullShape.cpp:140
btAssert
#define btAssert(x)
Definition: btScalar.h:133
btConvexHullShape::m_unscaledPoints
btAlignedObjectArray< btVector3 > m_unscaledPoints
Definition: btConvexHullShape.h:28
btVector3Data
#define btVector3Data
Definition: btVector3.h:27
btConvexInternalShape::m_localScaling
btVector3 m_localScaling
Definition: btConvexInternalShape.h:33
btCollisionMargin.h
btConvexHullComputer
Convex hull implementation based on Preparata and Hong See http://code.google.com/p/bullet/issues/det...
Definition: btConvexHullComputer.h:24
btSerializer
Definition: btSerializer.h:65
btVector3::normalize
btVector3 & normalize()
Normalize this vector x^2 + y^2 + z^2 = 1.
Definition: btVector3.h:303
btConvexHullShape::btConvexHullShape
btConvexHullShape(const btScalar *points=0, int numPoints=0, int stride=sizeof(btVector3))
this constructor optionally takes in a pointer to points.
Definition: btConvexHullShape.cpp:28
btVector3DataName
#define btVector3DataName
Definition: btVector3.h:28
btVector3::maxDot
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
btConvexHullShape::optimizeConvexHull
void optimizeConvexHull()
Definition: btConvexHullShape.cpp:116
btConvexInternalShape::serialize
virtual const char * serialize(void *dataBuffer, btSerializer *serializer) const
fills the dataBuffer and returns the struct name (and 0 on failure)
Definition: btConvexInternalShape.h:154
btConvexHullShapeData
do not change those serialization structures, it requires an updated sBulletDNAstr/sBulletDNAstr64 ...
Definition: btConvexHullShape.h:97
btQuaternion.h
btSwap
void btSwap(T &a, T &b)
Definition: btScalar.h:623
btConvexHullShape::getNumVertices
virtual int getNumVertices() const
Definition: btConvexHullShape.cpp:130
btConvexInternalShape::getMargin
virtual btScalar getMargin() const
Definition: btConvexInternalShape.h:106
btVector3::dot
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition: btVector3.h:229
btConvexHullComputer.h
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:108
btConvexHullShape::getScaledPoint
btVector3 getScaledPoint(int i) const
Definition: btConvexHullShape.h:58
btConvexHullShapeData::m_unscaledPointsFloatPtr
btVector3FloatData * m_unscaledPointsFloatPtr
Definition: btConvexHullShape.h:101
BT_ARRAY_CODE
#define BT_ARRAY_CODE
Definition: btSerializer.h:118
btConvexHullShape::getNumPlanes
virtual int getNumPlanes() const
Definition: btConvexHullShape.cpp:153
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:80
btAlignedObjectArray::size
int size() const
return the number of elements in the array
Definition: btAlignedObjectArray.h:149
btConvexHullComputer::vertices
btAlignedObjectArray< btVector3 > vertices
Definition: btConvexHullComputer.h:67
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:28
btPolyhedralConvexAabbCachingShape
The btPolyhedralConvexAabbCachingShape adds aabb caching to the btPolyhedralConvexShape.
Definition: btPolyhedralConvexShape.h:67
btSerializer::finalizeChunk
virtual void finalizeChunk(btChunk *chunk, const char *structType, int chunkCode, void *oldPtr)=0
btConvexHullShape::setLocalScaling
virtual void setLocalScaling(const btVector3 &scaling)
in case we receive negative scaling
Definition: btConvexHullShape.cpp:45
btConvexHullShape::localGetSupportingVertex
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const
Definition: btConvexHullShape.cpp:99
btConvexPolyhedron.h
btAlignedObjectArray::resize
void resize(int newsize, const T &fillData=T())
Definition: btAlignedObjectArray.h:210
CONVEX_HULL_SHAPE_PROXYTYPE
Definition: btBroadphaseProxy.h:34
btConvexHullShape::serialize
virtual const char * serialize(void *dataBuffer, btSerializer *serializer) const
fills the dataBuffer and returns the struct name (and 0 on failure)
Definition: btConvexHullShape.cpp:171
btConvexHullShape::addPoint
void addPoint(const btVector3 &point, bool recalculateLocalAabb=true)
Definition: btConvexHullShape.cpp:51
btConvexHullComputer::compute
btScalar compute(const void *coords, bool doubleCoords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
Definition: btConvexHullComputer.cpp:2653
btConvexHullShape.h
btConvexHullShape::getVertex
virtual void getVertex(int i, btVector3 &vtx) const
Definition: btConvexHullShape.cpp:148
btCollisionShape::m_shapeType
int m_shapeType
Definition: btCollisionShape.h:30
btChunk::m_oldPtr
void * m_oldPtr
Definition: btSerializer.h:52
btPolyhedralConvexAabbCachingShape::recalcLocalAabb
void recalcLocalAabb()
Definition: btPolyhedralConvexShape.cpp:505
btSerializer::allocate
virtual btChunk * allocate(size_t size, int numElements)=0
btConvexHullShape::batchedUnitVectorGetSupportingVertexWithoutMargin
virtual void batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3 *vectors, btVector3 *supportVerticesOut, int numVectors) const
Definition: btConvexHullShape.cpp:74
btConvexHullShapeData::m_padding3
char m_padding3[4]
Definition: btConvexHullShape.h:105
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:294
btConvexHullShape::localGetSupportingVertexWithoutMargin
virtual btVector3 localGetSupportingVertexWithoutMargin(const btVector3 &vec) const
Definition: btConvexHullShape.cpp:58
btSerializer.h
btConvexHullShapeData::m_numUnscaledPoints
int m_numUnscaledPoints
Definition: btConvexHullShape.h:104