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 
42 {
43 protected:
46  int m_linkA;
47  int m_linkB;
48 
49  int m_numRows;
53 
57 
58  // warning: the data block lay out is not consistent for all constraints
59  // data block laid out as follows:
60  // cached impulses. (one per row.)
61  // jacobians. (interleaved, row1 body1 then row1 body2 then row2 body 1 etc)
62  // positions. (one per row.)
64 
65  void applyDeltaVee(btMultiBodyJacobianData & data, btScalar * delta_vee, btScalar impulse, int velocityIndex, int ndof);
66 
67  btScalar fillMultiBodyConstraint(btMultiBodySolverConstraint & solverConstraint,
69  btScalar * jacOrgA, btScalar * jacOrgB,
70  const btVector3& constraintNormalAng,
71 
72  const btVector3& constraintNormalLin,
73  const btVector3& posAworld, const btVector3& posBworld,
74  btScalar posError,
75  const btContactSolverInfo& infoGlobal,
76  btScalar lowerLimit, btScalar upperLimit,
77  bool angConstraint = false,
78 
79  btScalar relaxation = 1.f,
80  bool isFriction = false, btScalar desiredVelocity = 0, btScalar cfmSlip = 0);
81 
82 public:
84 
85  btMultiBodyConstraint(btMultiBody * bodyA, btMultiBody * bodyB, int linkA, int linkB, int numRows, bool isUnilateral);
86  virtual ~btMultiBodyConstraint();
87 
88  void updateJacobianSizes();
89  void allocateJacobiansMultiDof();
90 
91  //many constraints have setFrameInB/setPivotInB. Will use 'getConstraintType' later.
92  virtual void setFrameInB(const btMatrix3x3& frameInB) {}
93  virtual void setPivotInB(const btVector3& pivotInB) {}
94 
95  virtual void finalizeMultiDof() = 0;
96 
97  virtual int getIslandIdA() const = 0;
98  virtual int getIslandIdB() const = 0;
99 
100  virtual void createConstraintRows(btMultiBodyConstraintArray & constraintRows,
102  const btContactSolverInfo& infoGlobal) = 0;
103 
104  int getNumRows() const
105  {
106  return m_numRows;
107  }
108 
110  {
111  return m_bodyA;
112  }
114  {
115  return m_bodyB;
116  }
117 
118  int getLinkA() const
119  {
120  return m_linkA;
121  }
122  int getLinkB() const
123  {
124  return m_linkB;
125  }
126  void internalSetAppliedImpulse(int dof, btScalar appliedImpulse)
127  {
128  btAssert(dof >= 0);
129  btAssert(dof < getNumRows());
130  m_data[dof] = appliedImpulse;
131  }
132 
134  {
135  btAssert(dof >= 0);
136  btAssert(dof < getNumRows());
137  return m_data[dof];
138  }
139  // current constraint position
140  // constraint is pos >= 0 for unilateral, or pos = 0 for bilateral
141  // NOTE: ignored position for friction rows.
142  btScalar getPosition(int row) const
143  {
144  return m_data[m_posOffset + row];
145  }
146 
147  void setPosition(int row, btScalar pos)
148  {
149  m_data[m_posOffset + row] = pos;
150  }
151 
152  bool isUnilateral() const
153  {
154  return m_isUnilateral;
155  }
156 
157  // jacobian blocks.
158  // each of size 6 + num_links. (jacobian2 is null if no body2.)
159  // format: 3 'omega' coefficients, 3 'v' coefficients, then the 'qdot' coefficients.
160  btScalar* jacobianA(int row)
161  {
162  return &m_data[m_numRows + row * m_jacSizeBoth];
163  }
164  const btScalar* jacobianA(int row) const
165  {
166  return &m_data[m_numRows + (row * m_jacSizeBoth)];
167  }
168  btScalar* jacobianB(int row)
169  {
170  return &m_data[m_numRows + (row * m_jacSizeBoth) + m_jacSizeA];
171  }
172  const btScalar* jacobianB(int row) const
173  {
174  return &m_data[m_numRows + (row * m_jacSizeBoth) + m_jacSizeA];
175  }
176 
178  {
179  return m_maxAppliedImpulse;
180  }
182  {
183  m_maxAppliedImpulse = maxImp;
184  }
185 
186  virtual void debugDraw(class btIDebugDraw * drawer) = 0;
187 
188  virtual void setGearRatio(btScalar ratio) {}
189  virtual void setGearAuxLink(int gearAuxLink) {}
190  virtual void setRelativePositionTarget(btScalar relPosTarget) {}
191  virtual void setErp(btScalar erp) {}
192 };
193 
194 #endif //BT_MULTIBODY_CONSTRAINT_H
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:133
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:26
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:80
#define ATTRIBUTE_ALIGNED16(a)
Definition: btScalar.h:84
btAlignedObjectArray< btVector3 > scratch_v
void setPosition(int row, btScalar pos)
#define BT_DECLARE_ALIGNED_ALLOCATOR()
Definition: btScalar.h:405
void setMaxAppliedImpulse(btScalar maxImp)
The btMatrix3x3 class implements a 3x3 rotation matrix, to perform linear algebra in combination with...
Definition: btMatrix3x3.h:46
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:294
btScalar getMaxAppliedImpulse() const