Placer

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 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.
*/
//osgParticle - Copyright (C) 2002 Marco Jez

#ifndef OSGPARTICLE_PLACER
#define OSGPARTICLE_PLACER 1

#include <osg/CopyOp>
#include <osg/Object>
#include <osg/Vec3>

namespace osgParticle
{

    class Particle;

    /**    An abstract base class for implementing <I>particle placers</I>. A placer is an object which take
        a particle as input, and places it somewhere by setting its position vector. Placer objects are
        used by the <CODE>ModularEmitter</CODE> class as part of the particle emission process.
    */
    class Placer: public osg::Object {
    public:
        inline Placer();
        inline Placer(const Placer& copy, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY);

        virtual const char* libraryName() const { return "osgParticle"; }
        virtual const char* className() const { return "Placer"; }
        virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const Placer *>(obj) != 0; }

        /// Place a particle. Must be implemented in descendant classes.
        virtual void place(Particle* P) const = 0;
        
        /// Volume of the placer. Can be implemented in descendant classes.
        virtual float volume() const { return 1.0f; }

        /// Return the control position of particles that placer will generate. Must be implemented in descendant classes.
        virtual osg::Vec3 getControlPosition() const = 0;

    protected:
        ~Placer() {}
        Placer& operator=(const Placer& ) { return *this; }
    };
    
    // INLINE FUNCTIONS
    
    inline Placer::Placer()
    : osg::Object()
    {
    }
    
    inline Placer::Placer(const Placer& copy, const osg::CopyOp& copyop)
    : osg::Object(copy, copyop)
    {
    }

}

#endif