Contact.h

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#ifndef SimTK_SIMBODY_CONTACT_H_
#define SimTK_SIMBODY_CONTACT_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) 2008-10 Stanford University and the Authors.        *
 * Authors: Peter Eastman                                                     *
 * Contributors: Michael Sherman                                              *
 *                                                                            *
 * 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"

namespace SimTK {


SimTK_DEFINE_UNIQUE_INDEX_TYPE(ContactSurfaceIndex);

SimTK_DEFINE_UNIQUE_INDEX_TYPE(ContactId);

SimTK_DEFINE_UNIQUE_INDEX_TYPE(ContactTypeId);


class ContactImpl;
class UntrackedContactImpl;
class BrokenContactImpl;
class CircularPointContactImpl;
class TriangleMeshContactImpl;
class PointContactImpl;


//==============================================================================
//                                CONTACT
//==============================================================================
class SimTK_SIMBODY_EXPORT Contact {
public:
    enum Condition {
        Unknown,    
        Untracked,  
        Anticipated,
        NewContact, 
        Ongoing,    
        Broken      
    };
    static const char* nameOfCondition(Condition);

    Contact() : impl(0) {}
    Contact(const Contact& source);
    ~Contact() {clear();}
    Contact& operator=(const Contact& source);
    void clear();
    bool isEmpty() const {return impl==0;}

    ContactId getContactId() const;
    Condition getCondition() const;
    ContactSurfaceIndex getSurface1() const;
    ContactSurfaceIndex getSurface2() const;
    const Transform& getTransform() const;

    Contact& setContactId(ContactId id);
    Contact& setCondition(Condition condition);
    Contact& setSurfaces(ContactSurfaceIndex surf1, ContactSurfaceIndex surf2);
    Contact& setTransform(const Transform& X_S1S2);

    ContactTypeId getTypeId() const;

    static ContactId createNewContactId();

    const ContactImpl& getImpl() const {assert(impl); return *impl;}
    ContactImpl&       updImpl()       {assert(impl); return *impl;}
protected:
    explicit Contact(ContactImpl* impl);
private:
    ContactImpl* impl;
};

inline std::ostream& operator<<(std::ostream& o, const Contact& c) {
    o << "Contact id=" << c.getContactId() 
                       << " (typeId=" << c.getTypeId() << "):\n";
    o << "  surf1,surf2=" << c.getSurface1() << ","
                          << c.getSurface2() << "\n";
    o << "  condition=" << Contact::nameOfCondition(c.getCondition()) << "\n";
    return o;
}



//==============================================================================
//                            UNTRACKED CONTACT
//==============================================================================
class SimTK_SIMBODY_EXPORT UntrackedContact : public Contact {
public:
    UntrackedContact() {}
    UntrackedContact(ContactSurfaceIndex surf1, ContactSurfaceIndex surf2); 

    static bool isInstance(const Contact& contact);
    static ContactTypeId classTypeId();

private:
    const UntrackedContactImpl& getImpl() const 
    {   assert(isInstance(*this)); 
        return reinterpret_cast<const UntrackedContactImpl&>
                    (Contact::getImpl()); }
};



//==============================================================================
//                            BROKEN CONTACT
//==============================================================================
class SimTK_SIMBODY_EXPORT BrokenContact : public Contact {
public:
    BrokenContact(ContactSurfaceIndex surf1, ContactSurfaceIndex surf2,
                  const Transform& X_S1S2, Real separation); 

    Real getSeparation() const;

    static bool isInstance(const Contact& contact);
    static ContactTypeId classTypeId();

private:
    const BrokenContactImpl& getImpl() const 
    {   assert(isInstance(*this)); 
        return reinterpret_cast<const BrokenContactImpl&>(Contact::getImpl()); }
};



//==============================================================================
//                           CIRCULAR POINT CONTACT
//==============================================================================
class SimTK_SIMBODY_EXPORT CircularPointContact : public Contact {
public:
    CircularPointContact
       (ContactSurfaceIndex surf1, Real radius1, 
        ContactSurfaceIndex surf2, Real radius2, 
        const Transform& X_S1S2, Real radius, Real depth, 
        const Vec3& origin_S1, const UnitVec3& normal_S1);

    Real getRadius1() const;
    Real getRadius2() const;
    Real getEffectiveRadius() const;
    Real getDepth() const;
    const Vec3& getOrigin() const;
    const UnitVec3& getNormal() const;

    static bool isInstance(const Contact& contact);
    static const CircularPointContact& getAs(const Contact& contact)
    {   assert(isInstance(contact)); 
        return static_cast<const CircularPointContact&>(contact); }
    static CircularPointContact& updAs(Contact& contact)
    {   assert(isInstance(contact)); 
        return static_cast<CircularPointContact&>(contact); }

    static ContactTypeId classTypeId();

private:
    const CircularPointContactImpl& getImpl() const 
    {   assert(isInstance(*this)); 
        return reinterpret_cast<const CircularPointContactImpl&>
                    (Contact::getImpl()); }
};



//==============================================================================
//                           TRIANGLE MESH CONTACT
//==============================================================================
class SimTK_SIMBODY_EXPORT TriangleMeshContact : public Contact {
public:
    TriangleMeshContact(ContactSurfaceIndex     surf1, 
                        ContactSurfaceIndex     surf2,
                        const Transform&        X_S1S2,
                        const std::set<int>&    faces1, 
                        const std::set<int>&    faces2);

    const std::set<int>& getSurface1Faces() const;
    const std::set<int>& getSurface2Faces() const;

    static bool isInstance(const Contact& contact);
    static const TriangleMeshContact& getAs(const Contact& contact)
    {   assert(isInstance(contact)); 
        return static_cast<const TriangleMeshContact&>(contact); }
    static TriangleMeshContact& updAs(Contact& contact)
    {   assert(isInstance(contact)); 
        return static_cast<TriangleMeshContact&>(contact); }

    static ContactTypeId classTypeId();

private:
    const TriangleMeshContactImpl& getImpl() const 
    {   assert(isInstance(*this)); 
        return reinterpret_cast<const TriangleMeshContactImpl&>
                    (Contact::getImpl()); }
};




//==============================================================================
//                           POINT CONTACT (OBSOLETE)
//==============================================================================
// OBSOLETE: this incorrectly includes the patch radius as part of the 
// geometric information, but the returned value assumes a Hertz elastic
// contact model. Use CircularPointContact instead.
class SimTK_SIMBODY_EXPORT PointContact : public Contact {
public:
    PointContact(ContactSurfaceIndex surf1, ContactSurfaceIndex surf2, 
                 Vec3& location, Vec3& normal, Real radius, Real depth);
    Vec3 getLocation() const;
    Vec3 getNormal() const;
    Real getRadius() const;
    Real getDepth() const;
    static bool isInstance(const Contact& contact);
    static ContactTypeId classTypeId();

private:
    const PointContactImpl& getImpl() const 
    {   assert(isInstance(*this)); 
        return reinterpret_cast<const PointContactImpl&>(Contact::getImpl()); }
};

} // namespace SimTK

#endif // SimTK_SIMBODY_CONTACT_H_