/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2010 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * OpenSceneGraph Public License for more details.
*/
// Written by Wang Rui, (C) 2010

#ifndef OSGPARTICLE_SINKOPERATOR
#define OSGPARTICLE_SINKOPERATOR

#include <osgParticle/Particle>
#include <osgParticle/DomainOperator>

namespace osgParticle
{


/** A sink operator kills particles if positions or velocities inside/outside the specified domain.
    Refer to David McAllister's Particle System API (http://www.particlesystems.org)
*/
class OSGPARTICLE_EXPORT SinkOperator : public DomainOperator
{
public:
    enum SinkTarget { SINK_POSITION, SINK_VELOCITY, SINK_ANGULAR_VELOCITY };
    enum SinkStrategy { SINK_INSIDE, SINK_OUTSIDE };

    SinkOperator()
    : DomainOperator(), _sinkTarget(SINK_POSITION), _sinkStrategy(SINK_INSIDE)
    {}

    SinkOperator( const SinkOperator& copy, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY )
    : DomainOperator(copy, copyop), _sinkTarget(copy._sinkTarget), _sinkStrategy(copy._sinkStrategy)
    {}

    META_Object( osgParticle, SinkOperator );

    /// Set the sink strategy
    void setSinkTarget( SinkTarget so ) { _sinkTarget = so; }

    /// Get the sink strategy
    SinkTarget getSinkTarget() const { return _sinkTarget; }

    /// Set the sink strategy
    void setSinkStrategy( SinkStrategy ss ) { _sinkStrategy = ss; }

    /// Get the sink strategy
    SinkStrategy getSinkStrategy() const { return _sinkStrategy; }

    /// Perform some initializations. Do not call this method manually.
    void beginOperate( Program* prg );

protected:
    virtual ~SinkOperator() {}
    SinkOperator& operator=( const SinkOperator& ) { return *this; }

    virtual void handlePoint( const Domain& domain, Particle* P, double dt );
    virtual void handleLineSegment( const Domain& domain, Particle* P, double dt );
    virtual void handleTriangle( const Domain& domain, Particle* P, double dt );
    virtual void handleRectangle( const Domain& domain, Particle* P, double dt );
    virtual void handlePlane( const Domain& domain, Particle* P, double dt );
    virtual void handleSphere( const Domain& domain, Particle* P, double dt );
    virtual void handleBox( const Domain& domain, Particle* P, double dt );
    virtual void handleDisk( const Domain& domain, Particle* P, double dt );

    inline const osg::Vec3& getValue( Particle* P );
    inline void kill( Particle* P, bool insideDomain );

    SinkTarget _sinkTarget;
    SinkStrategy _sinkStrategy;
};

// INLINE METHODS

inline const osg::Vec3& SinkOperator::getValue( Particle* P )
{
    switch ( _sinkTarget )
    {
    case SINK_VELOCITY: return P->getVelocity();
    case SINK_ANGULAR_VELOCITY: return P->getAngularVelocity();
    case SINK_POSITION: default: return P->getPosition();
    }
}

inline void SinkOperator::kill( Particle* P, bool insideDomain )
{
    if ( !((_sinkStrategy==SINK_INSIDE) ^ insideDomain) )
        P->kill();
}


}

#endif
