Bullet Collision Detection & Physics Library
btBox2dShape.h
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1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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 #ifndef BT_OBB_BOX_2D_SHAPE_H
17 #define BT_OBB_BOX_2D_SHAPE_H
18 
19 #include "BulletCollision/CollisionShapes/btPolyhedralConvexShape.h"
20 #include "BulletCollision/CollisionShapes/btCollisionMargin.h"
21 #include "BulletCollision/BroadphaseCollision/btBroadphaseProxy.h"
22 #include "LinearMath/btVector3.h"
23 #include "LinearMath/btMinMax.h"
24 
26 ATTRIBUTE_ALIGNED16(class) btBox2dShape: public btPolyhedralConvexShape
27 {
28 
29  //btVector3 m_boxHalfExtents1; //use m_implicitShapeDimensions instead
30 
31  btVector3 m_centroid;
32  btVector3 m_vertices[4];
33  btVector3 m_normals[4];
34 
35 public:
36 
37  BT_DECLARE_ALIGNED_ALLOCATOR();
38 
39  btVector3 getHalfExtentsWithMargin() const
40  {
41  btVector3 halfExtents = getHalfExtentsWithoutMargin();
42  btVector3 margin(getMargin(),getMargin(),getMargin());
43  halfExtents += margin;
44  return halfExtents;
45  }
46 
47  const btVector3& getHalfExtentsWithoutMargin() const
48  {
49  return m_implicitShapeDimensions;//changed in Bullet 2.63: assume the scaling and margin are included
50  }
51 
52 
53  virtual btVector3 localGetSupportingVertex(const btVector3& vec) const
54  {
55  btVector3 halfExtents = getHalfExtentsWithoutMargin();
56  btVector3 margin(getMargin(),getMargin(),getMargin());
57  halfExtents += margin;
58 
59  return btVector3(btFsels(vec.x(), halfExtents.x(), -halfExtents.x()),
60  btFsels(vec.y(), halfExtents.y(), -halfExtents.y()),
61  btFsels(vec.z(), halfExtents.z(), -halfExtents.z()));
62  }
63 
64  SIMD_FORCE_INLINE btVector3 localGetSupportingVertexWithoutMargin(const btVector3& vec)const
65  {
66  const btVector3& halfExtents = getHalfExtentsWithoutMargin();
67 
68  return btVector3(btFsels(vec.x(), halfExtents.x(), -halfExtents.x()),
69  btFsels(vec.y(), halfExtents.y(), -halfExtents.y()),
70  btFsels(vec.z(), halfExtents.z(), -halfExtents.z()));
71  }
72 
73  virtual void batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
74  {
75  const btVector3& halfExtents = getHalfExtentsWithoutMargin();
76 
77  for (int i=0;i<numVectors;i++)
78  {
79  const btVector3& vec = vectors[i];
80  supportVerticesOut[i].setValue(btFsels(vec.x(), halfExtents.x(), -halfExtents.x()),
81  btFsels(vec.y(), halfExtents.y(), -halfExtents.y()),
82  btFsels(vec.z(), halfExtents.z(), -halfExtents.z()));
83  }
84 
85  }
86 
87 
89  btBox2dShape( const btVector3& boxHalfExtents)
90  : btPolyhedralConvexShape(),
91  m_centroid(0,0,0)
92  {
93  m_vertices[0].setValue(-boxHalfExtents.getX(),-boxHalfExtents.getY(),0);
94  m_vertices[1].setValue(boxHalfExtents.getX(),-boxHalfExtents.getY(),0);
95  m_vertices[2].setValue(boxHalfExtents.getX(),boxHalfExtents.getY(),0);
96  m_vertices[3].setValue(-boxHalfExtents.getX(),boxHalfExtents.getY(),0);
97 
98  m_normals[0].setValue(0,-1,0);
99  m_normals[1].setValue(1,0,0);
100  m_normals[2].setValue(0,1,0);
101  m_normals[3].setValue(-1,0,0);
102 
103  btScalar minDimension = boxHalfExtents.getX();
104  if (minDimension>boxHalfExtents.getY())
105  minDimension = boxHalfExtents.getY();
106  setSafeMargin(minDimension);
107 
108  m_shapeType = BOX_2D_SHAPE_PROXYTYPE;
109  btVector3 margin(getMargin(),getMargin(),getMargin());
110  m_implicitShapeDimensions = (boxHalfExtents * m_localScaling) - margin;
111  };
112 
113  virtual void setMargin(btScalar collisionMargin)
114  {
115  //correct the m_implicitShapeDimensions for the margin
116  btVector3 oldMargin(getMargin(),getMargin(),getMargin());
117  btVector3 implicitShapeDimensionsWithMargin = m_implicitShapeDimensions+oldMargin;
118 
119  btConvexInternalShape::setMargin(collisionMargin);
120  btVector3 newMargin(getMargin(),getMargin(),getMargin());
121  m_implicitShapeDimensions = implicitShapeDimensionsWithMargin - newMargin;
122 
123  }
124  virtual void setLocalScaling(const btVector3& scaling)
125  {
126  btVector3 oldMargin(getMargin(),getMargin(),getMargin());
127  btVector3 implicitShapeDimensionsWithMargin = m_implicitShapeDimensions+oldMargin;
128  btVector3 unScaledImplicitShapeDimensionsWithMargin = implicitShapeDimensionsWithMargin / m_localScaling;
129 
130  btConvexInternalShape::setLocalScaling(scaling);
131 
132  m_implicitShapeDimensions = (unScaledImplicitShapeDimensionsWithMargin * m_localScaling) - oldMargin;
133 
134  }
135 
136  virtual void getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const;
137 
138 
139 
140  virtual void calculateLocalInertia(btScalar mass,btVector3& inertia) const;
141 
142 
143 
144 
145 
146  int getVertexCount() const
147  {
148  return 4;
149  }
150 
151  virtual int getNumVertices()const
152  {
153  return 4;
154  }
155 
156  const btVector3* getVertices() const
157  {
158  return &m_vertices[0];
159  }
160 
161  const btVector3* getNormals() const
162  {
163  return &m_normals[0];
164  }
165 
166 
167 
168 
169 
170 
171 
172  virtual void getPlane(btVector3& planeNormal,btVector3& planeSupport,int i ) const
173  {
174  //this plane might not be aligned...
175  btVector4 plane ;
176  getPlaneEquation(plane,i);
177  planeNormal = btVector3(plane.getX(),plane.getY(),plane.getZ());
178  planeSupport = localGetSupportingVertex(-planeNormal);
179  }
180 
181 
182  const btVector3& getCentroid() const
183  {
184  return m_centroid;
185  }
186 
187  virtual int getNumPlanes() const
188  {
189  return 6;
190  }
191 
192 
193 
194  virtual int getNumEdges() const
195  {
196  return 12;
197  }
198 
199 
200  virtual void getVertex(int i,btVector3& vtx) const
201  {
202  btVector3 halfExtents = getHalfExtentsWithoutMargin();
203 
204  vtx = btVector3(
205  halfExtents.x() * (1-(i&1)) - halfExtents.x() * (i&1),
206  halfExtents.y() * (1-((i&2)>>1)) - halfExtents.y() * ((i&2)>>1),
207  halfExtents.z() * (1-((i&4)>>2)) - halfExtents.z() * ((i&4)>>2));
208  }
209 
210 
211  virtual void getPlaneEquation(btVector4& plane,int i) const
212  {
213  btVector3 halfExtents = getHalfExtentsWithoutMargin();
214 
215  switch (i)
216  {
217  case 0:
218  plane.setValue(btScalar(1.),btScalar(0.),btScalar(0.),-halfExtents.x());
219  break;
220  case 1:
221  plane.setValue(btScalar(-1.),btScalar(0.),btScalar(0.),-halfExtents.x());
222  break;
223  case 2:
224  plane.setValue(btScalar(0.),btScalar(1.),btScalar(0.),-halfExtents.y());
225  break;
226  case 3:
227  plane.setValue(btScalar(0.),btScalar(-1.),btScalar(0.),-halfExtents.y());
228  break;
229  case 4:
230  plane.setValue(btScalar(0.),btScalar(0.),btScalar(1.),-halfExtents.z());
231  break;
232  case 5:
233  plane.setValue(btScalar(0.),btScalar(0.),btScalar(-1.),-halfExtents.z());
234  break;
235  default:
236  btAssert(0);
237  }
238  }
239 
240 
241  virtual void getEdge(int i,btVector3& pa,btVector3& pb) const
242  //virtual void getEdge(int i,Edge& edge) const
243  {
244  int edgeVert0 = 0;
245  int edgeVert1 = 0;
246 
247  switch (i)
248  {
249  case 0:
250  edgeVert0 = 0;
251  edgeVert1 = 1;
252  break;
253  case 1:
254  edgeVert0 = 0;
255  edgeVert1 = 2;
256  break;
257  case 2:
258  edgeVert0 = 1;
259  edgeVert1 = 3;
260 
261  break;
262  case 3:
263  edgeVert0 = 2;
264  edgeVert1 = 3;
265  break;
266  case 4:
267  edgeVert0 = 0;
268  edgeVert1 = 4;
269  break;
270  case 5:
271  edgeVert0 = 1;
272  edgeVert1 = 5;
273 
274  break;
275  case 6:
276  edgeVert0 = 2;
277  edgeVert1 = 6;
278  break;
279  case 7:
280  edgeVert0 = 3;
281  edgeVert1 = 7;
282  break;
283  case 8:
284  edgeVert0 = 4;
285  edgeVert1 = 5;
286  break;
287  case 9:
288  edgeVert0 = 4;
289  edgeVert1 = 6;
290  break;
291  case 10:
292  edgeVert0 = 5;
293  edgeVert1 = 7;
294  break;
295  case 11:
296  edgeVert0 = 6;
297  edgeVert1 = 7;
298  break;
299  default:
300  btAssert(0);
301 
302  }
303 
304  getVertex(edgeVert0,pa );
305  getVertex(edgeVert1,pb );
306  }
307 
308 
309 
310 
311 
312  virtual bool isInside(const btVector3& pt,btScalar tolerance) const
313  {
314  btVector3 halfExtents = getHalfExtentsWithoutMargin();
315 
316  //btScalar minDist = 2*tolerance;
317 
318  bool result = (pt.x() <= (halfExtents.x()+tolerance)) &&
319  (pt.x() >= (-halfExtents.x()-tolerance)) &&
320  (pt.y() <= (halfExtents.y()+tolerance)) &&
321  (pt.y() >= (-halfExtents.y()-tolerance)) &&
322  (pt.z() <= (halfExtents.z()+tolerance)) &&
323  (pt.z() >= (-halfExtents.z()-tolerance));
324 
325  return result;
326  }
327 
328 
329  //debugging
330  virtual const char* getName()const
331  {
332  return "Box2d";
333  }
334 
335  virtual int getNumPreferredPenetrationDirections() const
336  {
337  return 6;
338  }
339 
340  virtual void getPreferredPenetrationDirection(int index, btVector3& penetrationVector) const
341  {
342  switch (index)
343  {
344  case 0:
345  penetrationVector.setValue(btScalar(1.),btScalar(0.),btScalar(0.));
346  break;
347  case 1:
348  penetrationVector.setValue(btScalar(-1.),btScalar(0.),btScalar(0.));
349  break;
350  case 2:
351  penetrationVector.setValue(btScalar(0.),btScalar(1.),btScalar(0.));
352  break;
353  case 3:
354  penetrationVector.setValue(btScalar(0.),btScalar(-1.),btScalar(0.));
355  break;
356  case 4:
357  penetrationVector.setValue(btScalar(0.),btScalar(0.),btScalar(1.));
358  break;
359  case 5:
360  penetrationVector.setValue(btScalar(0.),btScalar(0.),btScalar(-1.));
361  break;
362  default:
363  btAssert(0);
364  }
365  }
366 
367 };
368 
369 #endif //BT_OBB_BOX_2D_SHAPE_H
370 
371 
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