btTypedConstraint.h

Go to the documentation of this file.

/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2010 Erwin Coumans  http://continuousphysics.com/Bullet/
 
This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, 
including commercial applications, and to alter it and redistribute it freely, 
subject to the following restrictions:
 
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.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
 
#ifndef BT_TYPED_CONSTRAINT_H
#define BT_TYPED_CONSTRAINT_H
 
#include "LinearMath/btScalar.h"
#include "btSolverConstraint.h"
#include "BulletDynamics/Dynamics/btRigidBody.h"
 
#ifdef BT_USE_DOUBLE_PRECISION
#define btTypedConstraintData2 btTypedConstraintDoubleData
#define btTypedConstraintDataName "btTypedConstraintDoubleData"
#else
#define btTypedConstraintData2 btTypedConstraintFloatData
#define btTypedConstraintDataName "btTypedConstraintFloatData"
#endif  //BT_USE_DOUBLE_PRECISION
 
class btSerializer;
 
//Don't change any of the existing enum values, so add enum types at the end for serialization compatibility
enum btTypedConstraintType
{
    POINT2POINT_CONSTRAINT_TYPE = 3,
    HINGE_CONSTRAINT_TYPE,
    CONETWIST_CONSTRAINT_TYPE,
    D6_CONSTRAINT_TYPE,
    SLIDER_CONSTRAINT_TYPE,
    CONTACT_CONSTRAINT_TYPE,
    D6_SPRING_CONSTRAINT_TYPE,
    GEAR_CONSTRAINT_TYPE,
    FIXED_CONSTRAINT_TYPE,
    D6_SPRING_2_CONSTRAINT_TYPE,
    MAX_CONSTRAINT_TYPE
};
 
enum btConstraintParams
{
    BT_CONSTRAINT_ERP = 1,
    BT_CONSTRAINT_STOP_ERP,
    BT_CONSTRAINT_CFM,
    BT_CONSTRAINT_STOP_CFM
};
 
#if 1
#define btAssertConstrParams(_par) btAssert(_par)
#else
#define btAssertConstrParams(_par)
#endif
 
ATTRIBUTE_ALIGNED16(struct)
btJointFeedback
{
    BT_DECLARE_ALIGNED_ALLOCATOR();
    btVector3 m_appliedForceBodyA;
    btVector3 m_appliedTorqueBodyA;
    btVector3 m_appliedForceBodyB;
    btVector3 m_appliedTorqueBodyB;
};

ATTRIBUTE_ALIGNED16(class)
btTypedConstraint : public btTypedObject
{
    int m_userConstraintType;
 
    union {
        int m_userConstraintId;
        void* m_userConstraintPtr;
    };
 
    btScalar m_breakingImpulseThreshold;
    bool m_isEnabled;
    bool m_needsFeedback;
    int m_overrideNumSolverIterations;
 
    btTypedConstraint& operator=(btTypedConstraint& other)
    {
        btAssert(0);
        (void)other;
        return *this;
    }
 
protected:
    btRigidBody& m_rbA;
    btRigidBody& m_rbB;
    btScalar m_appliedImpulse;
    btScalar m_dbgDrawSize;
    btJointFeedback* m_jointFeedback;

    btScalar getMotorFactor(btScalar pos, btScalar lowLim, btScalar uppLim, btScalar vel, btScalar timeFact);
 
public:
    BT_DECLARE_ALIGNED_ALLOCATOR();
 
    virtual ~btTypedConstraint(){};
    btTypedConstraint(btTypedConstraintType type, btRigidBody & rbA);
    btTypedConstraint(btTypedConstraintType type, btRigidBody & rbA, btRigidBody & rbB);
 
    struct btConstraintInfo1
    {
        int m_numConstraintRows, nub;
    };
 
    static btRigidBody& getFixedBody();
 
    struct btConstraintInfo2
    {
        // integrator parameters: frames per second (1/stepsize), default error
        // reduction parameter (0..1).
        btScalar fps, erp;
 
        // for the first and second body, pointers to two (linear and angular)
        // n*3 jacobian sub matrices, stored by rows. these matrices will have
        // been initialized to 0 on entry. if the second body is zero then the
        // J2xx pointers may be 0.
        btScalar *m_J1linearAxis, *m_J1angularAxis, *m_J2linearAxis, *m_J2angularAxis;
 
        // elements to jump from one row to the next in J's
        int rowskip;
 
        // right hand sides of the equation J*v = c + cfm * lambda. cfm is the
        // "constraint force mixing" vector. c is set to zero on entry, cfm is
        // set to a constant value (typically very small or zero) value on entry.
        btScalar *m_constraintError, *cfm;
 
        // lo and hi limits for variables (set to -/+ infinity on entry).
        btScalar *m_lowerLimit, *m_upperLimit;
 
        // number of solver iterations
        int m_numIterations;
 
        //damping of the velocity
        btScalar m_damping;
    };
 
    int getOverrideNumSolverIterations() const
    {
        return m_overrideNumSolverIterations;
    }

    void setOverrideNumSolverIterations(int overideNumIterations)
    {
        m_overrideNumSolverIterations = overideNumIterations;
    }

    virtual void buildJacobian(){};

    virtual void setupSolverConstraint(btConstraintArray & ca, int solverBodyA, int solverBodyB, btScalar timeStep)
    {
        (void)ca;
        (void)solverBodyA;
        (void)solverBodyB;
        (void)timeStep;
    }

    virtual void getInfo1(btConstraintInfo1 * info) = 0;

    virtual void getInfo2(btConstraintInfo2 * info) = 0;

    void internalSetAppliedImpulse(btScalar appliedImpulse)
    {
        m_appliedImpulse = appliedImpulse;
    }

    btScalar internalGetAppliedImpulse()
    {
        return m_appliedImpulse;
    }
 
    btScalar getBreakingImpulseThreshold() const
    {
        return m_breakingImpulseThreshold;
    }
 
    void setBreakingImpulseThreshold(btScalar threshold)
    {
        m_breakingImpulseThreshold = threshold;
    }
 
    bool isEnabled() const
    {
        return m_isEnabled;
    }
 
    void setEnabled(bool enabled)
    {
        m_isEnabled = enabled;
    }

    virtual void solveConstraintObsolete(btSolverBody& /*bodyA*/, btSolverBody& /*bodyB*/, btScalar /*timeStep*/){};
 
    const btRigidBody& getRigidBodyA() const
    {
        return m_rbA;
    }
    const btRigidBody& getRigidBodyB() const
    {
        return m_rbB;
    }
 
    btRigidBody& getRigidBodyA()
    {
        return m_rbA;
    }
    btRigidBody& getRigidBodyB()
    {
        return m_rbB;
    }
 
    int getUserConstraintType() const
    {
        return m_userConstraintType;
    }
 
    void setUserConstraintType(int userConstraintType)
    {
        m_userConstraintType = userConstraintType;
    };
 
    void setUserConstraintId(int uid)
    {
        m_userConstraintId = uid;
    }
 
    int getUserConstraintId() const
    {
        return m_userConstraintId;
    }
 
    void setUserConstraintPtr(void* ptr)
    {
        m_userConstraintPtr = ptr;
    }
 
    void* getUserConstraintPtr()
    {
        return m_userConstraintPtr;
    }
 
    void setJointFeedback(btJointFeedback * jointFeedback)
    {
        m_jointFeedback = jointFeedback;
    }
 
    const btJointFeedback* getJointFeedback() const
    {
        return m_jointFeedback;
    }
 
    btJointFeedback* getJointFeedback()
    {
        return m_jointFeedback;
    }
 
    int getUid() const
    {
        return m_userConstraintId;
    }
 
    bool needsFeedback() const
    {
        return m_needsFeedback;
    }

    void enableFeedback(bool needsFeedback)
    {
        m_needsFeedback = needsFeedback;
    }

    btScalar getAppliedImpulse() const
    {
        btAssert(m_needsFeedback);
        return m_appliedImpulse;
    }
 
    btTypedConstraintType getConstraintType() const
    {
        return btTypedConstraintType(m_objectType);
    }
 
    void setDbgDrawSize(btScalar dbgDrawSize)
    {
        m_dbgDrawSize = dbgDrawSize;
    }
    btScalar getDbgDrawSize()
    {
        return m_dbgDrawSize;
    }

    virtual void setParam(int num, btScalar value, int axis = -1) = 0;

    virtual btScalar getParam(int num, int axis = -1) const = 0;
 
    virtual int calculateSerializeBufferSize() const;

    virtual const char* serialize(void* dataBuffer, btSerializer* serializer) const;
};
 
// returns angle in range [-SIMD_2_PI, SIMD_2_PI], closest to one of the limits
// all arguments should be normalized angles (i.e. in range [-SIMD_PI, SIMD_PI])
SIMD_FORCE_INLINE btScalar btAdjustAngleToLimits(btScalar angleInRadians, btScalar angleLowerLimitInRadians, btScalar angleUpperLimitInRadians)
{
    if (angleLowerLimitInRadians >= angleUpperLimitInRadians)
    {
        return angleInRadians;
    }
    else if (angleInRadians < angleLowerLimitInRadians)
    {
        btScalar diffLo = btFabs(btNormalizeAngle(angleLowerLimitInRadians - angleInRadians));
        btScalar diffHi = btFabs(btNormalizeAngle(angleUpperLimitInRadians - angleInRadians));
        return (diffLo < diffHi) ? angleInRadians : (angleInRadians + SIMD_2_PI);
    }
    else if (angleInRadians > angleUpperLimitInRadians)
    {
        btScalar diffHi = btFabs(btNormalizeAngle(angleInRadians - angleUpperLimitInRadians));
        btScalar diffLo = btFabs(btNormalizeAngle(angleInRadians - angleLowerLimitInRadians));
        return (diffLo < diffHi) ? (angleInRadians - SIMD_2_PI) : angleInRadians;
    }
    else
    {
        return angleInRadians;
    }
}
 
// clang-format off

struct  btTypedConstraintFloatData
{
    btRigidBodyFloatData        *m_rbA;
    btRigidBodyFloatData        *m_rbB;
    char    *m_name;
 
    int m_objectType;
    int m_userConstraintType;
    int m_userConstraintId;
    int m_needsFeedback;
 
    float   m_appliedImpulse;
    float   m_dbgDrawSize;
 
    int m_disableCollisionsBetweenLinkedBodies;
    int m_overrideNumSolverIterations;
 
    float   m_breakingImpulseThreshold;
    int     m_isEnabled;
    
};
 
 

 
#define BT_BACKWARDS_COMPATIBLE_SERIALIZATION
#ifdef BT_BACKWARDS_COMPATIBLE_SERIALIZATION
struct  btTypedConstraintData
{
    btRigidBodyData     *m_rbA;
    btRigidBodyData     *m_rbB;
    char    *m_name;
 
    int m_objectType;
    int m_userConstraintType;
    int m_userConstraintId;
    int m_needsFeedback;
 
    float   m_appliedImpulse;
    float   m_dbgDrawSize;
 
    int m_disableCollisionsBetweenLinkedBodies;
    int m_overrideNumSolverIterations;
 
    float   m_breakingImpulseThreshold;
    int     m_isEnabled;
    
};
#endif //BACKWARDS_COMPATIBLE
 
struct  btTypedConstraintDoubleData
{
    btRigidBodyDoubleData       *m_rbA;
    btRigidBodyDoubleData       *m_rbB;
    char    *m_name;
 
    int m_objectType;
    int m_userConstraintType;
    int m_userConstraintId;
    int m_needsFeedback;
 
    double  m_appliedImpulse;
    double  m_dbgDrawSize;
 
    int m_disableCollisionsBetweenLinkedBodies;
    int m_overrideNumSolverIterations;
 
    double  m_breakingImpulseThreshold;
    int     m_isEnabled;
    char    padding[4];
    
};
 
// clang-format on
 
SIMD_FORCE_INLINE int btTypedConstraint::calculateSerializeBufferSize() const
{
    return sizeof(btTypedConstraintData2);
}
 
class btAngularLimit
{
private:
    btScalar
        m_center,
        m_halfRange,
        m_softness,
        m_biasFactor,
        m_relaxationFactor,
        m_correction,
        m_sign;
 
    bool
        m_solveLimit;
 
public:
    btAngularLimit()
        : m_center(0.0f),
          m_halfRange(-1.0f),
          m_softness(0.9f),
          m_biasFactor(0.3f),
          m_relaxationFactor(1.0f),
          m_correction(0.0f),
          m_sign(0.0f),
          m_solveLimit(false)
    {
    }

    void set(btScalar low, btScalar high, btScalar _softness = 0.9f, btScalar _biasFactor = 0.3f, btScalar _relaxationFactor = 1.0f);

    void test(const btScalar angle);

    inline btScalar getSoftness() const
    {
        return m_softness;
    }

    inline btScalar getBiasFactor() const
    {
        return m_biasFactor;
    }

    inline btScalar getRelaxationFactor() const
    {
        return m_relaxationFactor;
    }

    inline btScalar getCorrection() const
    {
        return m_correction;
    }

    inline btScalar getSign() const
    {
        return m_sign;
    }

    inline btScalar getHalfRange() const
    {
        return m_halfRange;
    }

    inline bool isLimit() const
    {
        return m_solveLimit;
    }

    void fit(btScalar& angle) const;

    btScalar getError() const;
 
    btScalar getLow() const;
 
    btScalar getHigh() const;
};
 
#endif  //BT_TYPED_CONSTRAINT_H