Bullet Collision Detection & Physics Library
btMultiBodyConstraint.h
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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_MULTIBODY_CONSTRAINT_H
17 #define BT_MULTIBODY_CONSTRAINT_H
18 
19 #include "LinearMath/btScalar.h"
21 #include "btMultiBody.h"
22 
23 class btMultiBody;
24 struct btSolverInfo;
25 
27 
29 {
31  btAlignedObjectArray<btScalar> m_deltaVelocitiesUnitImpulse; //holds the joint-space response of the corresp. tree to the test impulse in each constraint space dimension
32  btAlignedObjectArray<btScalar> m_deltaVelocities; //holds joint-space vectors of all the constrained trees accumulating the effect of corrective impulses applied in SI
38 
39 };
40 
41 
43 {
44 protected:
45 
48  int m_linkA;
49  int m_linkB;
50 
51  int m_numRows;
55 
59 
60 
61  // warning: the data block lay out is not consistent for all constraints
62  // data block laid out as follows:
63  // cached impulses. (one per row.)
64  // jacobians. (interleaved, row1 body1 then row1 body2 then row2 body 1 etc)
65  // positions. (one per row.)
67 
68  void applyDeltaVee(btMultiBodyJacobianData& data, btScalar* delta_vee, btScalar impulse, int velocityIndex, int ndof);
69 
70  btScalar fillMultiBodyConstraint(btMultiBodySolverConstraint& solverConstraint,
72  btScalar* jacOrgA, btScalar* jacOrgB,
73  const btVector3& constraintNormalAng,
74 
75  const btVector3& constraintNormalLin,
76  const btVector3& posAworld, const btVector3& posBworld,
77  btScalar posError,
78  const btContactSolverInfo& infoGlobal,
79  btScalar lowerLimit, btScalar upperLimit,
80  bool angConstraint = false,
81 
82  btScalar relaxation = 1.f,
83  bool isFriction = false, btScalar desiredVelocity=0, btScalar cfmSlip=0);
84 
85 public:
86 
88 
89  btMultiBodyConstraint(btMultiBody* bodyA,btMultiBody* bodyB,int linkA, int linkB, int numRows, bool isUnilateral);
90  virtual ~btMultiBodyConstraint();
91 
92  void updateJacobianSizes();
93  void allocateJacobiansMultiDof();
94 
95  //many constraints have setFrameInB/setPivotInB. Will use 'getConstraintType' later.
96  virtual void setFrameInB(const btMatrix3x3& frameInB) {}
97  virtual void setPivotInB(const btVector3& pivotInB){}
98 
99  virtual void finalizeMultiDof()=0;
100 
101  virtual int getIslandIdA() const =0;
102  virtual int getIslandIdB() const =0;
103 
104  virtual void createConstraintRows(btMultiBodyConstraintArray& constraintRows,
106  const btContactSolverInfo& infoGlobal)=0;
107 
108  int getNumRows() const
109  {
110  return m_numRows;
111  }
112 
114  {
115  return m_bodyA;
116  }
118  {
119  return m_bodyB;
120  }
121 
122  void internalSetAppliedImpulse(int dof, btScalar appliedImpulse)
123  {
124  btAssert(dof>=0);
125  btAssert(dof < getNumRows());
126  m_data[dof] = appliedImpulse;
127 
128  }
129 
131  {
132  btAssert(dof>=0);
133  btAssert(dof < getNumRows());
134  return m_data[dof];
135  }
136  // current constraint position
137  // constraint is pos >= 0 for unilateral, or pos = 0 for bilateral
138  // NOTE: ignored position for friction rows.
139  btScalar getPosition(int row) const
140  {
141  return m_data[m_posOffset + row];
142  }
143 
144  void setPosition(int row, btScalar pos)
145  {
146  m_data[m_posOffset + row] = pos;
147  }
148 
149 
150  bool isUnilateral() const
151  {
152  return m_isUnilateral;
153  }
154 
155  // jacobian blocks.
156  // each of size 6 + num_links. (jacobian2 is null if no body2.)
157  // format: 3 'omega' coefficients, 3 'v' coefficients, then the 'qdot' coefficients.
158  btScalar* jacobianA(int row)
159  {
160  return &m_data[m_numRows + row * m_jacSizeBoth];
161  }
162  const btScalar* jacobianA(int row) const
163  {
164  return &m_data[m_numRows + (row * m_jacSizeBoth)];
165  }
166  btScalar* jacobianB(int row)
167  {
168  return &m_data[m_numRows + (row * m_jacSizeBoth) + m_jacSizeA];
169  }
170  const btScalar* jacobianB(int row) const
171  {
172  return &m_data[m_numRows + (row * m_jacSizeBoth) + m_jacSizeA];
173  }
174 
176  {
177  return m_maxAppliedImpulse;
178  }
180  {
181  m_maxAppliedImpulse = maxImp;
182  }
183 
184  virtual void debugDraw(class btIDebugDraw* drawer)=0;
185 
186  virtual void setGearRatio(btScalar ratio) {}
187  virtual void setGearAuxLink(int gearAuxLink) {}
188  virtual void setRelativePositionTarget(btScalar relPosTarget){}
189  virtual void setErp(btScalar erp){}
190 
191 
192 };
193 
194 #endif //BT_MULTIBODY_CONSTRAINT_H
195 
const btScalar * jacobianA(int row) const
btScalar * jacobianB(int row)
1D constraint along a normal axis between bodyA and bodyB. It can be combined to solve contact and fr...
btAlignedObjectArray< btScalar > scratch_r
btAlignedObjectArray< btScalar > m_deltaVelocities
btAlignedObjectArray< btSolverBody > * m_solverBodyPool
btScalar getAppliedImpulse(int dof)
virtual void setPivotInB(const btVector3 &pivotInB)
virtual void setGearRatio(btScalar ratio)
void internalSetAppliedImpulse(int dof, btScalar appliedImpulse)
#define btAssert(x)
Definition: btScalar.h:131
btScalar * jacobianA(int row)
btScalar getPosition(int row) const
virtual void setErp(btScalar erp)
btAlignedObjectArray< btMatrix3x3 > scratch_m
virtual void setRelativePositionTarget(btScalar relPosTarget)
btAlignedObjectArray< btScalar > m_deltaVelocitiesUnitImpulse
const btScalar * jacobianB(int row) const
virtual void setFrameInB(const btMatrix3x3 &frameInB)
The btIDebugDraw interface class allows hooking up a debug renderer to visually debug simulations...
Definition: btIDebugDraw.h:29
virtual void setGearAuxLink(int gearAuxLink)
btAlignedObjectArray< btScalar > m_data
btAlignedObjectArray< btScalar > m_jacobians
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
#define ATTRIBUTE_ALIGNED16(a)
Definition: btScalar.h:82
btAlignedObjectArray< btVector3 > scratch_v
void setPosition(int row, btScalar pos)
#define BT_DECLARE_ALIGNED_ALLOCATOR()
Definition: btScalar.h:403
void setMaxAppliedImpulse(btScalar maxImp)
The btMatrix3x3 class implements a 3x3 rotation matrix, to perform linear algebra in combination with...
Definition: btMatrix3x3.h:48
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:292
btScalar getMaxAppliedImpulse() const