1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2013 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_FEATHERSTONE_LINK_COLLIDER_H
17 #define BT_FEATHERSTONE_LINK_COLLIDER_H
18 
19 #include "BulletCollision/CollisionDispatch/btCollisionObject.h"
20 
21 #include "btMultiBody.h"
22 #include "LinearMath/btSerializer.h"
23 
24 #ifdef BT_USE_DOUBLE_PRECISION
25 #define btMultiBodyLinkColliderData btMultiBodyLinkColliderDoubleData
26 #define btMultiBodyLinkColliderDataName "btMultiBodyLinkColliderDoubleData"
27 #else
28 #define btMultiBodyLinkColliderData btMultiBodyLinkColliderFloatData
29 #define btMultiBodyLinkColliderDataName "btMultiBodyLinkColliderFloatData"
30 #endif
31 
32 class btMultiBodyLinkCollider : public btCollisionObject
33 {
34 	//protected:
35 public:
36 	btMultiBody* m_multiBody;
37 	int m_link;
38 
~btMultiBodyLinkCollider()39 	virtual ~btMultiBodyLinkCollider()
40 	{
41 
42 	}
btMultiBodyLinkCollider(btMultiBody * multiBody,int link)43 	btMultiBodyLinkCollider(btMultiBody* multiBody, int link)
44 		: m_multiBody(multiBody),
45 		  m_link(link)
46 	{
47 		m_checkCollideWith = true;
48 		//we need to remove the 'CF_STATIC_OBJECT' flag, otherwise links/base doesn't merge islands
49 		//this means that some constraints might point to bodies that are not in the islands, causing crashes
50 		//if (link>=0 || (multiBody && !multiBody->hasFixedBase()))
51 		{
52 			m_collisionFlags &= (~btCollisionObject::CF_STATIC_OBJECT);
53 		}
54 		// else
55 		//{
56 		//	m_collisionFlags |= (btCollisionObject::CF_STATIC_OBJECT);
57 		//}
58 
59 		m_internalType = CO_FEATHERSTONE_LINK;
60 	}
upcast(btCollisionObject * colObj)61 	static btMultiBodyLinkCollider* upcast(btCollisionObject* colObj)
62 	{
63 		if (colObj->getInternalType() & btCollisionObject::CO_FEATHERSTONE_LINK)
64 			return (btMultiBodyLinkCollider*)colObj;
65 		return 0;
66 	}
upcast(const btCollisionObject * colObj)67 	static const btMultiBodyLinkCollider* upcast(const btCollisionObject* colObj)
68 	{
69 		if (colObj->getInternalType() & btCollisionObject::CO_FEATHERSTONE_LINK)
70 			return (btMultiBodyLinkCollider*)colObj;
71 		return 0;
72 	}
73 
checkCollideWithOverride(const btCollisionObject * co)74 	virtual bool checkCollideWithOverride(const btCollisionObject* co) const
75 	{
76 		const btMultiBodyLinkCollider* other = btMultiBodyLinkCollider::upcast(co);
77 		if (!other)
78 			return true;
79 		if (other->m_multiBody != this->m_multiBody)
80 			return true;
81 		if (!m_multiBody->hasSelfCollision())
82 			return false;
83 
84 		//check if 'link' has collision disabled
85 		if (m_link >= 0)
86 		{
87 			const btMultibodyLink& link = m_multiBody->getLink(this->m_link);
88 			if (link.m_flags & BT_MULTIBODYLINKFLAGS_DISABLE_ALL_PARENT_COLLISION)
89 			{
90 				int parent_of_this = m_link;
91 				while (1)
92 				{
93 					if (parent_of_this == -1)
94 						break;
95 					parent_of_this = m_multiBody->getLink(parent_of_this).m_parent;
96 					if (parent_of_this == other->m_link)
97 					{
98 						return false;
99 					}
100 				}
101 			}
102 			else if (link.m_flags & BT_MULTIBODYLINKFLAGS_DISABLE_PARENT_COLLISION)
103 			{
104 				if (link.m_parent == other->m_link)
105 					return false;
106 			}
107 		}
108 
109 		if (other->m_link >= 0)
110 		{
111 			const btMultibodyLink& otherLink = other->m_multiBody->getLink(other->m_link);
112 			if (otherLink.m_flags & BT_MULTIBODYLINKFLAGS_DISABLE_ALL_PARENT_COLLISION)
113 			{
114 				int parent_of_other = other->m_link;
115 				while (1)
116 				{
117 					if (parent_of_other == -1)
118 						break;
119 					parent_of_other = m_multiBody->getLink(parent_of_other).m_parent;
120 					if (parent_of_other == this->m_link)
121 						return false;
122 				}
123 			}
124 			else if (otherLink.m_flags & BT_MULTIBODYLINKFLAGS_DISABLE_PARENT_COLLISION)
125 			{
126 				if (otherLink.m_parent == this->m_link)
127 					return false;
128 			}
129 		}
130 		return true;
131 	}
132 
133 	virtual int calculateSerializeBufferSize() const;
134 
135 	///fills the dataBuffer and returns the struct name (and 0 on failure)
136 	virtual const char* serialize(void* dataBuffer, class btSerializer* serializer) const;
137 };
138 
139 // clang-format off
140 
141 struct	btMultiBodyLinkColliderFloatData
142 {
143 	btCollisionObjectFloatData m_colObjData;
144 	btMultiBodyFloatData	*m_multiBody;
145 	int			m_link;
146 	char		m_padding[4];
147 };
148 
149 struct	btMultiBodyLinkColliderDoubleData
150 {
151 	btCollisionObjectDoubleData m_colObjData;
152 	btMultiBodyDoubleData		*m_multiBody;
153 	int			m_link;
154 	char		m_padding[4];
155 };
156 
157 // clang-format on
158 
calculateSerializeBufferSize()159 SIMD_FORCE_INLINE int btMultiBodyLinkCollider::calculateSerializeBufferSize() const
160 {
161 	return sizeof(btMultiBodyLinkColliderData);
162 }
163 
serialize(void * dataBuffer,class btSerializer * serializer)164 SIMD_FORCE_INLINE const char* btMultiBodyLinkCollider::serialize(void* dataBuffer, class btSerializer* serializer) const
165 {
166 	btMultiBodyLinkColliderData* dataOut = (btMultiBodyLinkColliderData*)dataBuffer;
167 	btCollisionObject::serialize(&dataOut->m_colObjData, serializer);
168 
169 	dataOut->m_link = this->m_link;
170 	dataOut->m_multiBody = (btMultiBodyData*)serializer->getUniquePointer(m_multiBody);
171 
172 	// Fill padding with zeros to appease msan.
173 	memset(dataOut->m_padding, 0, sizeof(dataOut->m_padding));
174 
175 	return btMultiBodyLinkColliderDataName;
176 }
177 
178 #endif  //BT_FEATHERSTONE_LINK_COLLIDER_H
179