Bullet Collision Detection & Physics Library
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"
22
25#include "btConvexPolyhedron.h"
27
28btConvexHullShape ::btConvexHullShape(const btScalar* points, int numPoints, int stride) : btPolyhedralConvexAabbCachingShape()
29{
32
33 unsigned char* pointsAddress = (unsigned char*)points;
34
35 for (int i = 0; i < numPoints; i++)
36 {
38 m_unscaledPoints[i] = btVector3(point[0], point[1], point[2]);
39 pointsAddress += stride;
40 }
41
43}
44
46{
47 m_localScaling = scaling;
49}
50
51void btConvexHullShape::addPoint(const btVector3& point, bool recalculateLocalAabb)
52{
54 if (recalculateLocalAabb)
56}
57
59{
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
75{
77 //use 'w' component of supportVerticesOut?
78 {
79 for (int i = 0; i < numVectors; i++)
80 {
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 {
93 }
94 else
96 }
97}
98
100{
102
103 if (getMargin() != btScalar(0.))
104 {
106 if (vecnorm.length2() < (SIMD_EPSILON * SIMD_EPSILON))
107 {
108 vecnorm.setValue(btScalar(-1.), btScalar(-1.), btScalar(-1.));
109 }
110 vecnorm.normalize();
112 }
113 return supVertex;
114}
115
117{
119 conv.compute(&m_unscaledPoints[0].getX(), sizeof(btVector3), m_unscaledPoints.size(), 0.f, 0.f);
120 int numVerts = conv.vertices.size();
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
131{
132 return m_unscaledPoints.size();
133}
134
136{
137 return m_unscaledPoints.size();
138}
139
141{
142 int index0 = i % m_unscaledPoints.size();
143 int index1 = (i + 1) % m_unscaledPoints.size();
146}
147
149{
150 vtx = getScaledPoint(i);
151}
152
154{
155 return 0;
156}
157
159{
160 btAssert(0);
161}
162
163//not yet
165{
166 btAssert(0);
167 return false;
168}
169
172{
173 //int szc = sizeof(btConvexHullShapeData);
175 btConvexInternalShape::serialize(&shapeData->m_convexInternalShapeData, serializer);
176
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);
194 for (int i = 0; i < numElem; i++, memPtr++)
195 {
196 m_unscaledPoints[i].serialize(*memPtr);
197 }
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
208{
209#if 1
211 maxProj = -FLT_MAX;
212
214 for (int i = 0; i < numVerts; i++)
215 {
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();
234
235 minProj = witnesPtMin.dot(dir);
236 maxProj = witnesPtMax.dot(dir);
237#endif
238
239 if (minProj > maxProj)
240 {
243 }
244}
@ CONVEX_HULL_SHAPE_PROXYTYPE
const T & btMax(const T &a, const T &b)
Definition btMinMax.h:27
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition btScalar.h:314
#define BT_LARGE_FLOAT
Definition btScalar.h:316
#define SIMD_EPSILON
Definition btScalar.h:543
void btSwap(T &a, T &b)
Definition btScalar.h:643
#define btAssert(x)
Definition btScalar.h:153
#define BT_ARRAY_CODE
#define btVector3DataName
Definition btVector3.h:28
#define btVector3Data
Definition btVector3.h:27
int size() const
return the number of elements in the array
void resize(int newsize, const T &fillData=T())
void push_back(const T &_Val)
void * m_oldPtr
Convex hull implementation based on Preparata and Hong See http://code.google.com/p/bullet/issues/det...
btScalar compute(const void *coords, bool doubleCoords, int stride, int count, btScalar shrink, btScalar shrinkClamp)
btAlignedObjectArray< btVector3 > m_unscaledPoints
virtual int getNumPlanes() const
virtual int getNumVertices() const
virtual int getNumEdges() const
virtual void getVertex(int i, btVector3 &vtx) const
virtual bool isInside(const btVector3 &pt, btScalar tolerance) const
virtual void getEdge(int i, btVector3 &pa, btVector3 &pb) const
virtual void project(const btTransform &trans, const btVector3 &dir, btScalar &minProj, btScalar &maxProj, btVector3 &witnesPtMin, btVector3 &witnesPtMax) const
btVector3 getScaledPoint(int i) const
virtual void batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3 *vectors, btVector3 *supportVerticesOut, int numVectors) const
virtual btVector3 localGetSupportingVertexWithoutMargin(const btVector3 &vec) const
virtual const char * serialize(void *dataBuffer, btSerializer *serializer) const
fills the dataBuffer and returns the struct name (and 0 on failure)
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const
virtual void getPlane(btVector3 &planeNormal, btVector3 &planeSupport, int i) const
void addPoint(const btVector3 &point, bool recalculateLocalAabb=true)
virtual void setLocalScaling(const btVector3 &scaling)
in case we receive negative scaling
virtual const char * serialize(void *dataBuffer, btSerializer *serializer) const
fills the dataBuffer and returns the struct name (and 0 on failure)
virtual btScalar getMargin() const
The btPolyhedralConvexAabbCachingShape adds aabb caching to the btPolyhedralConvexShape.
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition btTransform.h:30
btVector3 can be used to represent 3D points and vectors.
Definition btVector3.h:82
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition btVector3.h:229
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition btVector3.h:640
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
do not change those serialization structures, it requires an updated sBulletDNAstr/sBulletDNAstr64