/* -*-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.
*/

#ifndef OSG_AUTOTRANSFORM
#define OSG_AUTOTRANSFORM 1

#include <osg/Group>
#include <osg/Transform>
#include <osg/Quat>
#include <osg/Viewport>

namespace osg {

/** AutoTransform is a derived form of Transform that automatically
  * scales or rotates to keep its children aligned with screen coordinates.
*/
class OSG_EXPORT AutoTransform : public Transform
{
    public :
        AutoTransform();

        AutoTransform(const AutoTransform& pat,const CopyOp& copyop=CopyOp::SHALLOW_COPY);            

        virtual osg::Object* cloneType() const { return new AutoTransform (); }
        virtual osg::Object* clone(const osg::CopyOp& copyop) const { return new AutoTransform (*this,copyop); }
        virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const AutoTransform *>(obj)!=NULL; }
        virtual const char* className() const { return "AutoTransform"; }
        virtual const char* libraryName() const { return "osg"; }

        virtual void accept(NodeVisitor& nv);

        virtual AutoTransform* asAutoTransform() { return this; }
        virtual const AutoTransform* asAutoTransform() const { return this; }

        inline void setPosition(const Vec3& pos) { _position = pos; _matrixDirty=true; dirtyBound(); }
        inline const Vec3& getPosition() const { return _position; }


        inline void setRotation(const Quat& quat) { _rotation = quat; _matrixDirty=true; dirtyBound(); }
        inline const Quat& getRotation() const { return _rotation; }
        
        inline void setScale(float scale) { _scale.set(scale,scale,scale); _matrixDirty=true; dirtyBound(); }
        inline void setScale(const Vec3& scale) { _scale = scale; _matrixDirty=true; dirtyBound(); }
        inline const Vec3& getScale() const { return _scale; }
        
        inline void setPivotPoint(const Vec3& pivot) { _pivotPoint = pivot; _matrixDirty=true; dirtyBound(); }
        inline const Vec3& getPivotPoint() const { return _pivotPoint; }
        

        void setAutoUpdateEyeMovementTolerance(float tolerance) { _autoUpdateEyeMovementTolerance = tolerance; }
        float getAutoUpdateEyeMovementTolerance() const { return _autoUpdateEyeMovementTolerance; }


        enum AutoRotateMode
        {
            NO_ROTATION,
            ROTATE_TO_SCREEN,
            ROTATE_TO_CAMERA
        };
        
        void setAutoRotateMode(AutoRotateMode mode) { _autoRotateMode = mode; _firstTimeToInitEyePoint = true; }

        AutoRotateMode getAutoRotateMode() const { return _autoRotateMode; }

        void setAutoScaleToScreen(bool autoScaleToScreen) { _autoScaleToScreen = autoScaleToScreen; _matrixDirty=true; }

        bool getAutoScaleToScreen() const { return _autoScaleToScreen; }


        virtual bool computeLocalToWorldMatrix(Matrix& matrix,NodeVisitor* nv) const;

        virtual bool computeWorldToLocalMatrix(Matrix& matrix,NodeVisitor* nv) const;

        virtual BoundingSphere computeBound() const;


    protected :
            
        virtual ~AutoTransform() {}

        Vec3                            _position;
        Vec3                            _pivotPoint;
        float                           _autoUpdateEyeMovementTolerance;

        AutoRotateMode                  _autoRotateMode;

        bool                            _autoScaleToScreen;
        
        mutable Quat                    _rotation;
        mutable Vec3                    _scale;
        mutable bool                    _firstTimeToInitEyePoint;
        mutable osg::Vec3               _previousEyePoint;
        mutable osg::Vec3               _previousLocalUp;
        mutable Viewport::value_type    _previousWidth;
        mutable Viewport::value_type    _previousHeight;        
        mutable osg::Matrix             _previousProjection;
        mutable osg::Vec3               _previousPosition;


        void computeMatrix() const;

        mutable bool        _matrixDirty;
        mutable osg::Matrix _cachedMatrix;
};

}

#endif