0623e351a9703fb564be8ed31ff99e74e4dba435
[blender-staging.git] / extern / bullet2 / src / BulletCollision / CollisionShapes / btConvexHullShape.cpp
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
26 btConvexHullShape ::btConvexHullShape (const btScalar* points,int numPoints,int stride) : btPolyhedralConvexAabbCachingShape ()
27 {
28         m_shapeType = CONVEX_HULL_SHAPE_PROXYTYPE;
29         m_unscaledPoints.resize(numPoints);
30
31         unsigned char* pointsAddress = (unsigned char*)points;
32
33         for (int i=0;i<numPoints;i++)
34         {
35                 btScalar* point = (btScalar*)pointsAddress;
36                 m_unscaledPoints[i] = btVector3(point[0], point[1], point[2]);
37                 pointsAddress += stride;
38         }
39
40         recalcLocalAabb();
41
42 }
43
44
45
46 void btConvexHullShape::setLocalScaling(const btVector3& scaling)
47 {
48         m_localScaling = scaling;
49         recalcLocalAabb();
50 }
51
52 void btConvexHullShape::addPoint(const btVector3& point, bool recalculateLocalAabb)
53 {
54         m_unscaledPoints.push_back(point);
55         if (recalculateLocalAabb)
56                 recalcLocalAabb();
57
58 }
59
60 btVector3       btConvexHullShape::localGetSupportingVertexWithoutMargin(const btVector3& vec)const
61 {
62         btVector3 supVec(btScalar(0.),btScalar(0.),btScalar(0.));
63         btScalar maxDot = btScalar(-BT_LARGE_FLOAT);
64
65     // Here we take advantage of dot(a, b*c) = dot(a*b, c).  Note: This is true mathematically, but not numerically. 
66     if( 0 < m_unscaledPoints.size() )
67     {
68         btVector3 scaled = vec * m_localScaling;
69         int index = (int) scaled.maxDot( &m_unscaledPoints[0], m_unscaledPoints.size(), maxDot); // FIXME: may violate encapsulation of m_unscaledPoints
70         return m_unscaledPoints[index] * m_localScaling;
71     }
72
73     return supVec;
74 }
75
76 void    btConvexHullShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
77 {
78         btScalar newDot;
79         //use 'w' component of supportVerticesOut?
80         {
81                 for (int i=0;i<numVectors;i++)
82                 {
83                         supportVerticesOut[i][3] = btScalar(-BT_LARGE_FLOAT);
84                 }
85         }
86
87     for (int j=0;j<numVectors;j++)
88     {
89         btVector3 vec = vectors[j] * m_localScaling;        // dot(a*b,c) = dot(a,b*c)
90         if( 0 <  m_unscaledPoints.size() )
91         {
92             int i = (int) vec.maxDot( &m_unscaledPoints[0], m_unscaledPoints.size(), newDot);
93             supportVerticesOut[j] = getScaledPoint(i);
94             supportVerticesOut[j][3] = newDot;        
95         }
96         else
97             supportVerticesOut[j][3] = -BT_LARGE_FLOAT;
98     }
99
100
101
102 }
103         
104
105
106 btVector3       btConvexHullShape::localGetSupportingVertex(const btVector3& vec)const
107 {
108         btVector3 supVertex = localGetSupportingVertexWithoutMargin(vec);
109
110         if ( getMargin()!=btScalar(0.) )
111         {
112                 btVector3 vecnorm = vec;
113                 if (vecnorm .length2() < (SIMD_EPSILON*SIMD_EPSILON))
114                 {
115                         vecnorm.setValue(btScalar(-1.),btScalar(-1.),btScalar(-1.));
116                 } 
117                 vecnorm.normalize();
118                 supVertex+= getMargin() * vecnorm;
119         }
120         return supVertex;
121 }
122
123
124
125
126
127
128
129
130
131 //currently just for debugging (drawing), perhaps future support for algebraic continuous collision detection
132 //Please note that you can debug-draw btConvexHullShape with the Raytracer Demo
133 int     btConvexHullShape::getNumVertices() const
134 {
135         return m_unscaledPoints.size();
136 }
137
138 int btConvexHullShape::getNumEdges() const
139 {
140         return m_unscaledPoints.size();
141 }
142
143 void btConvexHullShape::getEdge(int i,btVector3& pa,btVector3& pb) const
144 {
145
146         int index0 = i%m_unscaledPoints.size();
147         int index1 = (i+1)%m_unscaledPoints.size();
148         pa = getScaledPoint(index0);
149         pb = getScaledPoint(index1);
150 }
151
152 void btConvexHullShape::getVertex(int i,btVector3& vtx) const
153 {
154         vtx = getScaledPoint(i);
155 }
156
157 int     btConvexHullShape::getNumPlanes() const
158 {
159         return 0;
160 }
161
162 void btConvexHullShape::getPlane(btVector3& ,btVector3& ,int ) const
163 {
164
165         btAssert(0);
166 }
167
168 //not yet
169 bool btConvexHullShape::isInside(const btVector3& ,btScalar ) const
170 {
171         btAssert(0);
172         return false;
173 }
174
175 ///fills the dataBuffer and returns the struct name (and 0 on failure)
176 const char*     btConvexHullShape::serialize(void* dataBuffer, btSerializer* serializer) const
177 {
178         //int szc = sizeof(btConvexHullShapeData);
179         btConvexHullShapeData* shapeData = (btConvexHullShapeData*) dataBuffer;
180         btConvexInternalShape::serialize(&shapeData->m_convexInternalShapeData, serializer);
181
182         int numElem = m_unscaledPoints.size();
183         shapeData->m_numUnscaledPoints = numElem;
184 #ifdef BT_USE_DOUBLE_PRECISION
185         shapeData->m_unscaledPointsFloatPtr = 0;
186         shapeData->m_unscaledPointsDoublePtr = numElem ? (btVector3Data*)serializer->getUniquePointer((void*)&m_unscaledPoints[0]):  0;
187 #else
188         shapeData->m_unscaledPointsFloatPtr = numElem ? (btVector3Data*)serializer->getUniquePointer((void*)&m_unscaledPoints[0]):  0;
189         shapeData->m_unscaledPointsDoublePtr = 0;
190 #endif
191         
192         if (numElem)
193         {
194                 int sz = sizeof(btVector3Data);
195         //      int sz2 = sizeof(btVector3DoubleData);
196         //      int sz3 = sizeof(btVector3FloatData);
197                 btChunk* chunk = serializer->allocate(sz,numElem);
198                 btVector3Data* memPtr = (btVector3Data*)chunk->m_oldPtr;
199                 for (int i=0;i<numElem;i++,memPtr++)
200                 {
201                         m_unscaledPoints[i].serialize(*memPtr);
202                 }
203                 serializer->finalizeChunk(chunk,btVector3DataName,BT_ARRAY_CODE,(void*)&m_unscaledPoints[0]);
204         }
205         
206         return "btConvexHullShapeData";
207 }
208
209 void btConvexHullShape::project(const btTransform& trans, const btVector3& dir, btScalar& minProj, btScalar& maxProj, btVector3& witnesPtMin,btVector3& witnesPtMax) const
210 {
211 #if 1
212         minProj = FLT_MAX;
213         maxProj = -FLT_MAX;
214
215         int numVerts = m_unscaledPoints.size();
216         for(int i=0;i<numVerts;i++)
217         {
218                 btVector3 vtx = m_unscaledPoints[i] * m_localScaling;
219                 btVector3 pt = trans * vtx;
220                 btScalar dp = pt.dot(dir);
221                 if(dp < minProj)        
222                 {
223                         minProj = dp;
224                         witnesPtMin = pt;
225                 }
226                 if(dp > maxProj)        
227                 {
228                         maxProj = dp;
229                         witnesPtMax=pt;
230                 }
231         }
232 #else
233         btVector3 localAxis = dir*trans.getBasis();
234         witnesPtMin  = trans(localGetSupportingVertex(localAxis));
235         witnesPtMax = trans(localGetSupportingVertex(-localAxis));
236
237         minProj = witnesPtMin.dot(dir);
238         maxProj = witnesPtMax.dot(dir);
239 #endif
240
241         if(minProj>maxProj)
242         {
243                 btSwap(minProj,maxProj);
244                 btSwap(witnesPtMin,witnesPtMax);
245         }
246
247
248 }
249
250