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

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btConvexHullShape.cpp
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1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2009 Erwin Coumans http://bulletphysics.org
4
5This software is provided 'as-is', without any express or implied warranty.
6In no event will the authors be held liable for any damages arising from the use of this software.
7Permission is granted to anyone to use this software for any purpose,
8including commercial applications, and to alter it and redistribute it freely,
9subject to the following restrictions:
10
111. 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.
122. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
133. 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
28btConvexHullShape ::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}
CONVEX_HULL_SHAPE_PROXYTYPE
@ CONVEX_HULL_SHAPE_PROXYTYPE
Definition btBroadphaseProxy.h:34
btCollisionMargin.h
btConvexHullComputer.h
btConvexHullShape.h
btConvexPolyhedron.h
btQuaternion.h
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition btScalar.h:314
BT_LARGE_FLOAT
#define BT_LARGE_FLOAT
Definition btScalar.h:316
SIMD_EPSILON
#define SIMD_EPSILON
Definition btScalar.h:543
btSwap
void btSwap(T &a, T &b)
Definition btScalar.h:643
btAssert
#define btAssert(x)
Definition btScalar.h:153
btSerializer.h
BT_ARRAY_CODE
#define BT_ARRAY_CODE
Definition btSerializer.h:118
btVector3DataName
#define btVector3DataName
Definition btVector3.h:28
btVector3Data
#define btVector3Data
Definition btVector3.h:27
btAlignedObjectArray::size
int size() const
return the number of elements in the array
Definition btAlignedObjectArray.h:142
btAlignedObjectArray::resize
void resize(int newsize, const T &fillData=T())
Definition btAlignedObjectArray.h:203
btAlignedObjectArray::push_back
void push_back(const T &_Val)
Definition btAlignedObjectArray.h:257
btChunk
Definition btSerializer.h:48
btChunk::m_oldPtr
void * m_oldPtr
Definition btSerializer.h:52
btCollisionShape::m_shapeType
int m_shapeType
Definition btCollisionShape.h:30
btConvexHullComputer
Convex hull implementation based on Preparata and Hong See http://code.google.com/p/bullet/issues/det...
Definition btConvexHullComputer.h:25
btConvexHullComputer::compute
btScalar compute(const void *coords, bool doubleCoords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
Definition btConvexHullComputer.cpp:2653
btConvexHullComputer::vertices
btAlignedObjectArray< btVector3 > vertices
Definition btConvexHullComputer.h:67
btConvexHullShape::m_unscaledPoints
btAlignedObjectArray< btVector3 > m_unscaledPoints
Definition btConvexHullShape.h:29
btConvexHullShape::getNumPlanes
virtual int getNumPlanes() const
Definition btConvexHullShape.cpp:153
btConvexHullShape::getNumVertices
virtual int getNumVertices() const
Definition btConvexHullShape.cpp:130
btConvexHullShape::optimizeConvexHull
void optimizeConvexHull()
Definition btConvexHullShape.cpp:116
btConvexHullShape::getNumEdges
virtual int getNumEdges() const
Definition btConvexHullShape.cpp:135
btConvexHullShape::getVertex
virtual void getVertex(int i, btVector3 &vtx) const
Definition btConvexHullShape.cpp:148
btConvexHullShape::isInside
virtual bool isInside(const btVector3 &pt, btScalar tolerance) const
Definition btConvexHullShape.cpp:164
btConvexHullShape::getEdge
virtual void getEdge(int i, btVector3 &pa, btVector3 &pb) const
Definition btConvexHullShape.cpp:140
btConvexHullShape::project
virtual void project(const btTransform &trans, const btVector3 &dir, btScalar &minProj, btScalar &maxProj, btVector3 &witnesPtMin, btVector3 &witnesPtMax) const
Definition btConvexHullShape.cpp:207
btConvexHullShape::getScaledPoint
btVector3 getScaledPoint(int i) const
Definition btConvexHullShape.h:59
btConvexHullShape::batchedUnitVectorGetSupportingVertexWithoutMargin
virtual void batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3 *vectors, btVector3 *supportVerticesOut, int numVectors) const
Definition btConvexHullShape.cpp:74
btConvexHullShape::localGetSupportingVertexWithoutMargin
virtual btVector3 localGetSupportingVertexWithoutMargin(const btVector3 &vec) const
Definition btConvexHullShape.cpp:58
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::localGetSupportingVertex
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const
Definition btConvexHullShape.cpp:99
btConvexHullShape::getPlane
virtual void getPlane(btVector3 &planeNormal, btVector3 &planeSupport, int i) const
Definition btConvexHullShape.cpp:158
btConvexHullShape::addPoint
void addPoint(const btVector3 &point, bool recalculateLocalAabb=true)
Definition btConvexHullShape.cpp:51
btConvexHullShape::setLocalScaling
virtual void setLocalScaling(const btVector3 &scaling)
in case we receive negative scaling
Definition btConvexHullShape.cpp:45
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
btConvexInternalShape::m_localScaling
btVector3 m_localScaling
Definition btConvexInternalShape.h:33
btConvexInternalShape::getMargin
virtual btScalar getMargin() const
Definition btConvexInternalShape.h:106
btPolyhedralConvexAabbCachingShape
The btPolyhedralConvexAabbCachingShape adds aabb caching to the btPolyhedralConvexShape.
Definition btPolyhedralConvexShape.h:68
btPolyhedralConvexAabbCachingShape::recalcLocalAabb
void recalcLocalAabb()
Definition btPolyhedralConvexShape.cpp:505
btSerializer
Definition btSerializer.h:66
btSerializer::allocate
virtual btChunk * allocate(size_t size, int numElements)=0
btSerializer::getUniquePointer
virtual void * getUniquePointer(void *oldPtr)=0
btSerializer::finalizeChunk
virtual void finalizeChunk(btChunk *chunk, const char *structType, int chunkCode, void *oldPtr)=0
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition btTransform.h:30
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition btTransform.h:109
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition btVector3.h:82
btVector3::dot
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition btVector3.h:229
btVector3::setValue
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition btVector3.h:640
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
btVector3::length2
btScalar length2() const
Return the length of the vector squared.
Definition btVector3.h:251
btVector3::normalize
btVector3 & normalize()
Normalize this vector x^2 + y^2 + z^2 = 1.
Definition btVector3.h:303
btConvexHullShapeData
do not change those serialization structures, it requires an updated sBulletDNAstr/sBulletDNAstr64
Definition btConvexHullShape.h:99
btConvexHullShapeData::m_unscaledPointsDoublePtr
btVector3DoubleData * m_unscaledPointsDoublePtr
Definition btConvexHullShape.h:103
btConvexHullShapeData::m_unscaledPointsFloatPtr
btVector3FloatData * m_unscaledPointsFloatPtr
Definition btConvexHullShape.h:102
btConvexHullShapeData::m_convexInternalShapeData
btConvexInternalShapeData m_convexInternalShapeData
Definition btConvexHullShape.h:100
btConvexHullShapeData::m_padding3
char m_padding3[4]
Definition btConvexHullShape.h:106
btConvexHullShapeData::m_numUnscaledPoints
int m_numUnscaledPoints
Definition btConvexHullShape.h:105