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
46
47
48 void btConvexHullShape::setLocalScaling(const btVector3& scaling)
49 {
50 m_localScaling = scaling;
51 recalcLocalAabb();
52 }
53
54 void btConvexHullShape::addPoint(const btVector3& point, bool recalculateLocalAabb)
55 {
56 m_unscaledPoints.push_back(point);
57 if (recalculateLocalAabb)
58 recalcLocalAabb();
59
60 }
61
62 btVector3 btConvexHullShape::localGetSupportingVertexWithoutMargin(const btVector3& vec)const
63 {
64 btVector3 supVec(btScalar(0.),btScalar(0.),btScalar(0.));
65 btScalar maxDot = btScalar(-BT_LARGE_FLOAT);
66
67 // Here we take advantage of dot(a, b*c) = dot(a*b, c). Note: This is true mathematically, but not numerically.
68 if( 0 < m_unscaledPoints.size() )
69 {
70 btVector3 scaled = vec * m_localScaling;
71 int index = (int) scaled.maxDot( &m_unscaledPoints[0], m_unscaledPoints.size(), maxDot); // FIXME: may violate encapsulation of m_unscaledPoints
72 return m_unscaledPoints[index] * m_localScaling;
73 }
74
75 return supVec;
76 }
77
78 void btConvexHullShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
79 {
80 btScalar newDot;
81 //use 'w' component of supportVerticesOut?
82 {
83 for (int i=0;i<numVectors;i++)
84 {
85 supportVerticesOut[i][3] = btScalar(-BT_LARGE_FLOAT);
86 }
87 }
88
89 for (int j=0;j<numVectors;j++)
90 {
91 btVector3 vec = vectors[j] * m_localScaling; // dot(a*b,c) = dot(a,b*c)
92 if( 0 < m_unscaledPoints.size() )
93 {
94 int i = (int) vec.maxDot( &m_unscaledPoints[0], m_unscaledPoints.size(), newDot);
95 supportVerticesOut[j] = getScaledPoint(i);
96 supportVerticesOut[j][3] = newDot;
97 }
98 else
99 supportVerticesOut[j][3] = -BT_LARGE_FLOAT;
100 }
101
102
103
104 }
105
106
107
108 btVector3 btConvexHullShape::localGetSupportingVertex(const btVector3& vec)const
109 {
110 btVector3 supVertex = localGetSupportingVertexWithoutMargin(vec);
111
112 if ( getMargin()!=btScalar(0.) )
113 {
114 btVector3 vecnorm = vec;
115 if (vecnorm .length2() < (SIMD_EPSILON*SIMD_EPSILON))
116 {
117 vecnorm.setValue(btScalar(-1.),btScalar(-1.),btScalar(-1.));
118 }
119 vecnorm.normalize();
120 supVertex+= getMargin() * vecnorm;
121 }
122 return supVertex;
123 }
124
125
126 void btConvexHullShape::optimizeConvexHull()
127 {
128 btConvexHullComputer conv;
129 conv.compute(&m_unscaledPoints[0].getX(), sizeof(btVector3),m_unscaledPoints.size(),0.f,0.f);
130 int numVerts = conv.vertices.size();
131 m_unscaledPoints.resize(0);
132 for (int i=0;i<numVerts;i++)
133 {
134 m_unscaledPoints.push_back(conv.vertices[i]);
135 }
136 }
137
138
139
140 //currently just for debugging (drawing), perhaps future support for algebraic continuous collision detection
141 //Please note that you can debug-draw btConvexHullShape with the Raytracer Demo
142 int btConvexHullShape::getNumVertices() const
143 {
144 return m_unscaledPoints.size();
145 }
146
147 int btConvexHullShape::getNumEdges() const
148 {
149 return m_unscaledPoints.size();
150 }
151
152 void btConvexHullShape::getEdge(int i,btVector3& pa,btVector3& pb) const
153 {
154
155 int index0 = i%m_unscaledPoints.size();
156 int index1 = (i+1)%m_unscaledPoints.size();
157 pa = getScaledPoint(index0);
158 pb = getScaledPoint(index1);
159 }
160
161 void btConvexHullShape::getVertex(int i,btVector3& vtx) const
162 {
163 vtx = getScaledPoint(i);
164 }
165
166 int btConvexHullShape::getNumPlanes() const
167 {
168 return 0;
169 }
170
171 void btConvexHullShape::getPlane(btVector3& ,btVector3& ,int ) const
172 {
173
174 btAssert(0);
175 }
176
177 //not yet
178 bool btConvexHullShape::isInside(const btVector3& ,btScalar ) const
179 {
180 btAssert(0);
181 return false;
182 }
183
185 const char* btConvexHullShape::serialize(void* dataBuffer, btSerializer* serializer) const
186 {
187 //int szc = sizeof(btConvexHullShapeData);
188 btConvexHullShapeData* shapeData = (btConvexHullShapeData*) dataBuffer;
189 btConvexInternalShape::serialize(&shapeData->m_convexInternalShapeData, serializer);
190
191 int numElem = m_unscaledPoints.size();
192 shapeData->m_numUnscaledPoints = numElem;
193 #ifdef BT_USE_DOUBLE_PRECISION
194 shapeData->m_unscaledPointsFloatPtr = 0;
195 shapeData->m_unscaledPointsDoublePtr = numElem ? (btVector3Data*)serializer->getUniquePointer((void*)&m_unscaledPoints[0]): 0;
196 #else
197 shapeData->m_unscaledPointsFloatPtr = numElem ? (btVector3Data*)serializer->getUniquePointer((void*)&m_unscaledPoints[0]): 0;
198 shapeData->m_unscaledPointsDoublePtr = 0;
199 #endif
200
201 if (numElem)
202 {
203 int sz = sizeof(btVector3Data);
204 // int sz2 = sizeof(btVector3DoubleData);
205 // int sz3 = sizeof(btVector3FloatData);
206 btChunk* chunk = serializer->allocate(sz,numElem);
207 btVector3Data* memPtr = (btVector3Data*)chunk->m_oldPtr;
208 for (int i=0;i<numElem;i++,memPtr++)
209 {
210 m_unscaledPoints[i].serialize(*memPtr);
211 }
212 serializer->finalizeChunk(chunk,btVector3DataName,BT_ARRAY_CODE,(void*)&m_unscaledPoints[0]);
213 }
214
215 return "btConvexHullShapeData";
216 }
217
218 void btConvexHullShape::project(const btTransform& trans, const btVector3& dir, btScalar& minProj, btScalar& maxProj, btVector3& witnesPtMin,btVector3& witnesPtMax) const
219 {
220 #if 1
221 minProj = FLT_MAX;
222 maxProj = -FLT_MAX;
223
224 int numVerts = m_unscaledPoints.size();
225 for(int i=0;i<numVerts;i++)
226 {
227 btVector3 vtx = m_unscaledPoints[i] * m_localScaling;
228 btVector3 pt = trans * vtx;
229 btScalar dp = pt.dot(dir);
230 if(dp < minProj)
231 {
232 minProj = dp;
233 witnesPtMin = pt;
234 }
235 if(dp > maxProj)
236 {
237 maxProj = dp;
238 witnesPtMax=pt;
239 }
240 }
241 #else
242 btVector3 localAxis = dir*trans.getBasis();
243 witnesPtMin = trans(localGetSupportingVertex(localAxis));
244 witnesPtMax = trans(localGetSupportingVertex(-localAxis));
245
246 minProj = witnesPtMin.dot(dir);
247 maxProj = witnesPtMax.dot(dir);
248 #endif
249
250 if(minProj>maxProj)
251 {
252 btSwap(minProj,maxProj);
253 btSwap(witnesPtMin,witnesPtMax);
254 }
255
256
257 }
258
259
btConvexHullShape::isInside
virtual bool isInside(const btVector3 &pt, btScalar tolerance) const
Definition: btConvexHullShape.cpp:178
SIMD_EPSILON
#define SIMD_EPSILON
Definition: btScalar.h:495
btConvexHullShape::getNumEdges
virtual int getNumEdges() const
Definition: btConvexHullShape.cpp:147
btAlignedObjectArray::push_back
void push_back(const T &_Val)
Definition: btAlignedObjectArray.h:274
BT_LARGE_FLOAT
#define BT_LARGE_FLOAT
Definition: btScalar.h:281
btChunk
Definition: btSerializer.h:51
btVector3::setValue
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition: btVector3.h:650
btConvexHullShape::getPlane
virtual void getPlane(btVector3 &planeNormal, btVector3 &planeSupport, int i) const
Definition: btConvexHullShape.cpp:171
btSerializer::getUniquePointer
virtual void * getUniquePointer(void *oldPtr)=0
btConvexHullShapeData::m_convexInternalShapeData
btConvexInternalShapeData m_convexInternalShapeData
Definition: btConvexHullShape.h:103
btConvexHullShape::project
virtual void project(const btTransform &trans, const btVector3 &dir, btScalar &minProj, btScalar &maxProj, btVector3 &witnesPtMin, btVector3 &witnesPtMax) const
Definition: btConvexHullShape.cpp:218
btConvexHullShapeData::m_unscaledPointsDoublePtr
btVector3DoubleData * m_unscaledPointsDoublePtr
Definition: btConvexHullShape.h:106
btConvexHullShape::getEdge
virtual void getEdge(int i, btVector3 &pa, btVector3 &pb) const
Definition: btConvexHullShape.cpp:152
btAssert
#define btAssert(x)
Definition: btScalar.h:114
btConvexHullShape::m_unscaledPoints
btAlignedObjectArray< btVector3 > m_unscaledPoints
Definition: btConvexHullShape.h:28
btVector3Data
#define btVector3Data
Definition: btVector3.h:29
btConvexInternalShape::m_localScaling
btVector3 m_localScaling
Definition: btConvexInternalShape.h:35
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:68
btVector3::normalize
btVector3 & normalize()
Normalize this vector x^2 + y^2 + z^2 = 1.
Definition: btVector3.h:307
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:30
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:1011
btConvexHullShape::optimizeConvexHull
void optimizeConvexHull()
Definition: btConvexHullShape.cpp:126
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:166
btConvexHullShapeData
do not change those serialization structures, it requires an updated sBulletDNAstr/sBulletDNAstr64 ...
Definition: btConvexHullShape.h:101
btQuaternion.h
btSwap
void btSwap(T &a, T &b)
Definition: btScalar.h:586
btConvexHullShape::getNumVertices
virtual int getNumVertices() const
Definition: btConvexHullShape.cpp:142
btConvexInternalShape::getMargin
virtual btScalar getMargin() const
Definition: btConvexInternalShape.h:113
btVector3::dot
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition: btVector3.h:235
btConvexHullComputer.h
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:112
btConvexHullShape::getScaledPoint
btVector3 getScaledPoint(int i) const
Definition: btConvexHullShape.h:60
btConvexHullShapeData::m_unscaledPointsFloatPtr
btVector3FloatData * m_unscaledPointsFloatPtr
Definition: btConvexHullShape.h:105
BT_ARRAY_CODE
#define BT_ARRAY_CODE
Definition: btSerializer.h:126
btConvexHullShape::getNumPlanes
virtual int getNumPlanes() const
Definition: btConvexHullShape.cpp:166
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
btAlignedObjectArray::size
int size() const
return the number of elements in the array
Definition: btAlignedObjectArray.h:155
btConvexHullComputer::vertices
btAlignedObjectArray< btVector3 > vertices
Definition: btConvexHullComputer.h:69
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:34
btPolyhedralConvexAabbCachingShape
The btPolyhedralConvexAabbCachingShape adds aabb caching to the btPolyhedralConvexShape.
Definition: btPolyhedralConvexShape.h:73
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:48
btConvexHullShape::localGetSupportingVertex
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const
Definition: btConvexHullShape.cpp:108
btConvexPolyhedron.h
btAlignedObjectArray::resize
void resize(int newsize, const T &fillData=T())
Definition: btAlignedObjectArray.h:218
CONVEX_HULL_SHAPE_PROXYTYPE
Definition: btBroadphaseProxy.h:35
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:185
btConvexHullShape::addPoint
void addPoint(const btVector3 &point, bool recalculateLocalAabb=true)
Definition: btConvexHullShape.cpp:54
btConvexHullComputer::compute
btScalar compute(const void *coords, bool doubleCoords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
Definition: btConvexHullComputer.cpp:2645
btConvexHullShape.h
btConvexHullShape::getVertex
virtual void getVertex(int i, btVector3 &vtx) const
Definition: btConvexHullShape.cpp:161
btCollisionShape::m_shapeType
int m_shapeType
Definition: btCollisionShape.h:30
btChunk::m_oldPtr
void * m_oldPtr
Definition: btSerializer.h:56
btPolyhedralConvexAabbCachingShape::recalcLocalAabb
void recalcLocalAabb()
Definition: btPolyhedralConvexShape.cpp:450
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:78
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:279
btConvexHullShape::localGetSupportingVertexWithoutMargin
virtual btVector3 localGetSupportingVertexWithoutMargin(const btVector3 &vec) const
Definition: btConvexHullShape.cpp:62
btSerializer.h
btConvexHullShapeData::m_numUnscaledPoints
int m_numUnscaledPoints
Definition: btConvexHullShape.h:108