Force.h

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#ifndef SimTK_SIMBODY_FORCE_H_
#define SimTK_SIMBODY_FORCE_H_
/* -------------------------------------------------------------------------- *
 *                      SimTK Core: SimTK Simbody(tm)                         *
 * -------------------------------------------------------------------------- *
 * This is part of the SimTK Core biosimulation toolkit originating from      *
 * Simbios, the NIH National Center for Physics-Based Simulation of           *
 * Biological Structures at Stanford, funded under the NIH Roadmap for        *
 * Medical Research, grant U54 GM072970. See https://simtk.org.               *
 *                                                                            *
 * Portions copyright (c) 2008 Stanford University and the Authors.           *
 * Authors: Peter Eastman                                                     *
 * Contributors:                                                              *
 *                                                                            *
 * Permission is hereby granted, free of charge, to any person obtaining a    *
 * copy of this software and associated documentation files (the "Software"), *
 * to deal in the Software without restriction, including without limitation  *
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,   *
 * and/or sell copies of the Software, and to permit persons to whom the      *
 * Software is furnished to do so, subject to the following conditions:       *
 *                                                                            *
 * The above copyright notice and this permission notice shall be included in *
 * all copies or substantial portions of the Software.                        *
 *                                                                            *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,   *
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL    *
 * THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,    *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR      *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE  *
 * USE OR OTHER DEALINGS IN THE SOFTWARE.                                     *
 * -------------------------------------------------------------------------- */

#include "SimTKcommon.h"
#include "simbody/internal/common.h"
#include "simbody/internal/GeneralForceSubsystem.h"

namespace SimTK {

class SimbodyMatterSubsystem;
class GeneralForceSubsystem;
class MobilizedBody;
class Force;
class ForceImpl;

// We only want the template instantiation to occur once. This symbol is defined in the SimTK core
// compilation unit that defines the Force class but should not be defined any other time.
#ifndef SimTK_SIMBODY_DEFINING_FORCE
    extern template class PIMPLHandle<Force, ForceImpl, true>;
#endif

class SimTK_SIMBODY_EXPORT Force : public PIMPLHandle<Force, ForceImpl, true> {
public:
    Force() { }
    explicit Force(ForceImpl* r) : HandleBase(r) { }

    ForceIndex getForceIndex() const;
    
    class TwoPointLinearSpring;
    class TwoPointLinearDamper;
    class TwoPointConstantForce;
    class MobilityLinearSpring;
    class MobilityLinearDamper;
    class MobilityConstantForce;
    class ConstantForce;
    class ConstantTorque;
    class GlobalDamper;
    class UniformGravity;
    class Custom;
    
    class TwoPointLinearSpringImpl;
    class TwoPointLinearDamperImpl;
    class TwoPointConstantForceImpl;
    class MobilityLinearSpringImpl;
    class MobilityLinearDamperImpl;
    class MobilityConstantForceImpl;
    class ConstantForceImpl;
    class ConstantTorqueImpl;
    class GlobalDamperImpl;
    class UniformGravityImpl;
    class CustomImpl;
};

class SimTK_SIMBODY_EXPORT Force::TwoPointLinearSpring : public Force {
public:
    TwoPointLinearSpring(GeneralForceSubsystem& forces, const MobilizedBody& body1, const Vec3& station1, const MobilizedBody& body2, const Vec3& station2, Real k, Real x0);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(TwoPointLinearSpring, TwoPointLinearSpringImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::TwoPointLinearDamper: public Force {
public:
    TwoPointLinearDamper(GeneralForceSubsystem& forces, const MobilizedBody& body1, const Vec3& station1, const MobilizedBody& body2, const Vec3& station2, Real damping);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(TwoPointLinearDamper, TwoPointLinearDamperImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::TwoPointConstantForce: public Force {
public:
    TwoPointConstantForce(GeneralForceSubsystem& forces, const MobilizedBody& body1, const Vec3& station1, const MobilizedBody& body2, const Vec3& station2, Real force);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(TwoPointConstantForce, TwoPointConstantForceImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::MobilityLinearSpring : public Force {
public:
    MobilityLinearSpring(GeneralForceSubsystem& forces, const MobilizedBody& body, int coordinate, Real k, Real q0);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(MobilityLinearSpring, MobilityLinearSpringImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::MobilityLinearDamper : public Force {
public:
    MobilityLinearDamper(GeneralForceSubsystem& forces, const MobilizedBody& body, int coordinate, Real damping);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(MobilityLinearDamper, MobilityLinearDamperImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::MobilityConstantForce : public Force {
public:
    MobilityConstantForce(GeneralForceSubsystem& forces, const MobilizedBody& body, int coordinate, Real force);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(MobilityConstantForce, MobilityConstantForceImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::ConstantForce: public Force {
public:
    ConstantForce(GeneralForceSubsystem& forces, const MobilizedBody& body, const Vec3& station, const Vec3& force);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(ConstantForce, ConstantForceImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::ConstantTorque: public Force {
public:
    ConstantTorque(GeneralForceSubsystem& forces, const MobilizedBody& body, const Vec3& torque);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(ConstantTorque, ConstantTorqueImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::GlobalDamper : public Force {
public:
    GlobalDamper(GeneralForceSubsystem& forces, const SimbodyMatterSubsystem& matter, Real damping);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(GlobalDamper, GlobalDamperImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::UniformGravity : public Force {
public:
    UniformGravity(GeneralForceSubsystem& forces, const SimbodyMatterSubsystem& matter, const Vec3& g, Real zeroHeight=0);
    Vec3 getGravity() const;
    void setGravity(const Vec3& g);
    Real getZeroHeight() const;
    void setZeroHeight(Real height);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(UniformGravity, UniformGravityImpl, Force);
};

class SimTK_SIMBODY_EXPORT Force::Custom : public Force {
public:
    class Implementation;
    Custom(GeneralForceSubsystem& forces, Implementation* implementation);
    SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(Custom, CustomImpl, Force);
protected:
    const Implementation& getImplementation() const;
    Implementation& updImplementation();
};

class SimTK_SIMBODY_EXPORT Force::Custom::Implementation {
public:
    virtual ~Implementation() { }
    virtual void calcForce(const State& state, Vector_<SpatialVec>& bodyForces, Vector_<Vec3>& particleForces, Vector& mobilityForces) const = 0;
    virtual Real calcPotentialEnergy(const State& state) const = 0;
    virtual bool dependsOnlyOnPositions() const {
        return false;
    }
    virtual void realizeTopology(State& state) const {
    }
    virtual void realizeModel(State& state) const {
    }
    virtual void realizeInstance(const State& state) const {
    }
    virtual void realizeTime(const State& state) const {
    }
    virtual void realizePosition(const State& state) const {
    }
    virtual void realizeVelocity(const State& state) const {
    }
    virtual void realizeDynamics(const State& state) const {
    }
    virtual void realizeAcceleration(const State& state) const {
    }
    virtual void realizeReport(const State& state) const {
    }
};

} // namespace SimTK

#endif // SimTK_SIMBODY_FORCE_H_