//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.

#ifndef OSGGA_ANIMATION_PATH_MANIPULATOR
#define OSGGA_ANIMATION_PATH_MANIPULATOR 1

#include <osg/AnimationPath>
#include <osg/Notify>
#include <osgGA/CameraManipulator>

namespace osgGA{

//
// The AnimationPathManipulator is a Camera Manipulator that reads an
// animation path from a file and plays it back.  The file is expected
// to be ascii and a succession of lines with 8 floating point values
// per line.  The succession of values are:
// time  px py pz ax ay az aw
// where:
//    time = elapsed time in seconds from the begining of the animation
//    px py pz = World position in catesian coordinates
//    ax ay az aw = Orientation (attitude) defined as a quaternion

class AnimationPathManipulator : public osgGA::CameraManipulator
{
    public:
	    AnimationPathManipulator( std::string filename ) 
	    {
    	        _animationPath = new osg::AnimationPath;
    		_animationPath->setLoopMode(osg::AnimationPath::LOOP);

		FILE *fp = fopen( filename.c_str(), "r" );
		if( fp == NULL )
		{
		    osg::notify(osg::WARN) << "AnimationPathManipulator: Cannot open animation path file \"" << filename << "\".\n";
		    _valid = false;
		    return;
		}
		while( !feof( fp ))
		{
		    double time;
        	    osg::Vec3 position;
        	    osg::Quat rotation;
		    fscanf( fp, "%lf %f %f %f %f %f %f %f\n",
			&time, &position[0], &position[1], &position[2],
			&rotation[0], &rotation[1], &rotation[2], &rotation[3] );

		    if( !feof(fp))
        	        _animationPath->insert(time,osg::AnimationPath::ControlPoint(position,rotation));
		}
		fclose(fp);
		_valid = true;
	    }

	    bool valid() { return _valid; }

            virtual bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& us)
	    {
		if( !_valid ) return false;

		us = us;

		bool retval = false;
		switch( ea.getEventType() )
		{
		    case GUIEventAdapter::FRAME:
			handleFrame( ea.time() );
			 
			break;
		    case GUIEventAdapter::KEYBOARD:
			switch( ea.getKey())
			{
			    default:
				retval =  false;
			}
			break;
		}
		return retval;
	    }
    private:

	bool _valid;

	void handleFrame( double time )
	{
	    osg::AnimationPath::ControlPoint cp;
	    _animationPath->getInterpolatedControlPoint( time, cp );

	    osg::Matrix mat;
	    cp.getMatrix( mat );

	    osg::Vec3 eye(mat(3,0), mat(3,1), mat(3,2));
	    mat(3,0) = 0.0;
	    mat(3,1) = 0.0;
	    mat(3,2) = 0.0;
	    osg::Vec3 look = eye + (osg::Vec3(0,1,0) * mat);
	    osg::Vec3 up = osg::Vec3(0,0,1) * mat;
	    if( _camera.valid() )
		_camera->setView( eye, look, up );
	}

	osg::AnimationPath *_animationPath;

};

}

#endif