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 #ifndef BT_CONVEX_INTERNAL_SHAPE_H
17 #define BT_CONVEX_INTERNAL_SHAPE_H
18
19 #include "btConvexShape.h"
20 #include "LinearMath/btAabbUtil2.h"
21
22
23 ///The btConvexInternalShape is an internal base class, shared by most convex shape implementations.
24 ///The btConvexInternalShape uses a default collision margin set to CONVEX_DISTANCE_MARGIN.
25 ///This collision margin used by Gjk and some other algorithms, see also btCollisionMargin.h
26 ///Note that when creating small shapes (derived from btConvexInternalShape),
27 ///you need to make sure to set a smaller collision margin, using the 'setMargin' API
28 ///There is a automatic mechanism 'setSafeMargin' used by btBoxShape and btCylinderShape
ATTRIBUTE_ALIGNED16(class)29 ATTRIBUTE_ALIGNED16(class) btConvexInternalShape : public btConvexShape
30 {
31
32 protected:
33
34 //local scaling. collisionMargin is not scaled !
35 btVector3 m_localScaling;
36
37 btVector3 m_implicitShapeDimensions;
38
39 btScalar m_collisionMargin;
40
41 btScalar m_padding;
42
43 btConvexInternalShape();
44
45 public:
46
47 BT_DECLARE_ALIGNED_ALLOCATOR();
48
49 virtual ~btConvexInternalShape()
50 {
51
52 }
53
54 virtual btVector3 localGetSupportingVertex(const btVector3& vec)const;
55
56 const btVector3& getImplicitShapeDimensions() const
57 {
58 return m_implicitShapeDimensions;
59 }
60
61 ///warning: use setImplicitShapeDimensions with care
62 ///changing a collision shape while the body is in the world is not recommended,
63 ///it is best to remove the body from the world, then make the change, and re-add it
64 ///alternatively flush the contact points, see documentation for 'cleanProxyFromPairs'
65 void setImplicitShapeDimensions(const btVector3& dimensions)
66 {
67 m_implicitShapeDimensions = dimensions;
68 }
69
70 void setSafeMargin(btScalar minDimension, btScalar defaultMarginMultiplier = 0.1f)
71 {
72 btScalar safeMargin = defaultMarginMultiplier*minDimension;
73 if (safeMargin < getMargin())
74 {
75 setMargin(safeMargin);
76 }
77 }
78 void setSafeMargin(const btVector3& halfExtents, btScalar defaultMarginMultiplier = 0.1f)
79 {
80 //see http://code.google.com/p/bullet/issues/detail?id=349
81 //this margin check could could be added to other collision shapes too,
82 //or add some assert/warning somewhere
83 btScalar minDimension=halfExtents[halfExtents.minAxis()];
84 setSafeMargin(minDimension, defaultMarginMultiplier);
85 }
86
87 ///getAabb's default implementation is brute force, expected derived classes to implement a fast dedicated version
88 void getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const
89 {
90 getAabbSlow(t,aabbMin,aabbMax);
91 }
92
93
94
95 virtual void getAabbSlow(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const;
96
97
98 virtual void setLocalScaling(const btVector3& scaling);
99 virtual const btVector3& getLocalScaling() const
100 {
101 return m_localScaling;
102 }
103
104 const btVector3& getLocalScalingNV() const
105 {
106 return m_localScaling;
107 }
108
109 virtual void setMargin(btScalar margin)
110 {
111 m_collisionMargin = margin;
112 }
113 virtual btScalar getMargin() const
114 {
115 return m_collisionMargin;
116 }
117
118 btScalar getMarginNV() const
119 {
120 return m_collisionMargin;
121 }
122
123 virtual int getNumPreferredPenetrationDirections() const
124 {
125 return 0;
126 }
127
128 virtual void getPreferredPenetrationDirection(int index, btVector3& penetrationVector) const
129 {
130 (void)penetrationVector;
131 (void)index;
132 btAssert(0);
133 }
134
135 virtual int calculateSerializeBufferSize() const;
136
137 ///fills the dataBuffer and returns the struct name (and 0 on failure)
138 virtual const char* serialize(void* dataBuffer, btSerializer* serializer) const;
139
140
141 };
142
143 ///do not change those serialization structures, it requires an updated sBulletDNAstr/sBulletDNAstr64
144 struct btConvexInternalShapeData
145 {
146 btCollisionShapeData m_collisionShapeData;
147
148 btVector3FloatData m_localScaling;
149
150 btVector3FloatData m_implicitShapeDimensions;
151
152 float m_collisionMargin;
153
154 int m_padding;
155
156 };
157
158
159
calculateSerializeBufferSize()160 SIMD_FORCE_INLINE int btConvexInternalShape::calculateSerializeBufferSize() const
161 {
162 return sizeof(btConvexInternalShapeData);
163 }
164
165 ///fills the dataBuffer and returns the struct name (and 0 on failure)
serialize(void * dataBuffer,btSerializer * serializer)166 SIMD_FORCE_INLINE const char* btConvexInternalShape::serialize(void* dataBuffer, btSerializer* serializer) const
167 {
168 btConvexInternalShapeData* shapeData = (btConvexInternalShapeData*) dataBuffer;
169 btCollisionShape::serialize(&shapeData->m_collisionShapeData, serializer);
170
171 m_implicitShapeDimensions.serializeFloat(shapeData->m_implicitShapeDimensions);
172 m_localScaling.serializeFloat(shapeData->m_localScaling);
173 shapeData->m_collisionMargin = float(m_collisionMargin);
174
175 return "btConvexInternalShapeData";
176 }
177
178
179
180
181 ///btConvexInternalAabbCachingShape adds local aabb caching for convex shapes, to avoid expensive bounding box calculations
182 class btConvexInternalAabbCachingShape : public btConvexInternalShape
183 {
184 btVector3 m_localAabbMin;
185 btVector3 m_localAabbMax;
186 bool m_isLocalAabbValid;
187
188 protected:
189
190 btConvexInternalAabbCachingShape();
191
setCachedLocalAabb(const btVector3 & aabbMin,const btVector3 & aabbMax)192 void setCachedLocalAabb (const btVector3& aabbMin, const btVector3& aabbMax)
193 {
194 m_isLocalAabbValid = true;
195 m_localAabbMin = aabbMin;
196 m_localAabbMax = aabbMax;
197 }
198
getCachedLocalAabb(btVector3 & aabbMin,btVector3 & aabbMax)199 inline void getCachedLocalAabb (btVector3& aabbMin, btVector3& aabbMax) const
200 {
201 btAssert(m_isLocalAabbValid);
202 aabbMin = m_localAabbMin;
203 aabbMax = m_localAabbMax;
204 }
205
getNonvirtualAabb(const btTransform & trans,btVector3 & aabbMin,btVector3 & aabbMax,btScalar margin)206 inline void getNonvirtualAabb(const btTransform& trans,btVector3& aabbMin,btVector3& aabbMax, btScalar margin) const
207 {
208
209 //lazy evaluation of local aabb
210 btAssert(m_isLocalAabbValid);
211 btTransformAabb(m_localAabbMin,m_localAabbMax,margin,trans,aabbMin,aabbMax);
212 }
213
214 public:
215
216 virtual void setLocalScaling(const btVector3& scaling);
217
218 virtual void getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const;
219
220 void recalcLocalAabb();
221
222 };
223
224 #endif //BT_CONVEX_INTERNAL_SHAPE_H
225