/***************************************************************************
  qgs3danimationsettings.h
  --------------------------------------
  Date                 : July 2018
  Copyright            : (C) 2018 by Martin Dobias
  Email                : wonder dot sk at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGS3DANIMATIONSETTINGS_H
#define QGS3DANIMATIONSETTINGS_H

#include "qgis_3d.h"
#include "qgsvector3d.h"

#include <QEasingCurve>
#include <QVector>

#define SIP_NO_FILE

class QDomDocument;
class QDomElement;
class QgsReadWriteContext;


/**
 * \ingroup qgis_3d
 * \brief Holds information about animation in 3D view.
 *
 * The animation is defined as a series of keyframes.
 * \note Not available in Python bindings
 * \since QGIS 3.8
 */
class _3D_EXPORT Qgs3DAnimationSettings
{
  public:
    Qgs3DAnimationSettings();

    //! keyframe definition
    struct Keyframe
    {
        float time = 0;    //!< Relative time of the keyframe in seconds
        QgsVector3D point; //!< Point towards which the camera is looking in 3D map coords
        float dist = 0;    //!< Distance of the camera from the focal point
        float pitch = 0;   //!< Tilt of the camera in degrees (0 = looking from the top, 90 = looking from the side, 180 = looking from the bottom)
        float yaw = 0;     //!< Horizontal rotation around the focal point in degrees
    };

    typedef QVector<Keyframe> Keyframes;

    //! Configures keyframes of the animation. It is expected that the keyframes are ordered according to their time.
    void setKeyframes( const Keyframes &keyframes ) { mKeyframes = keyframes; }
    //! Returns keyframes of the animation
    Keyframes keyFrames() const { return mKeyframes; }

    //! Sets the interpolation method for transitions of the camera
    void setEasingCurve( const QEasingCurve &curve ) { mEasingCurve = curve; }
    //! Returns the interpolation method for transitions of the camera
    QEasingCurve easingCurve() const { return mEasingCurve; }

    //! Returns duration of the whole animation in seconds
    float duration() const;

    //! Interpolates camera position and rotation at the given point in time
    Keyframe interpolate( float time ) const;

    //! Reads configuration from a DOM element previously written by writeXml()
    void readXml( const QDomElement &elem );
    //! Writes configuration to a DOM element, to be used later with readXml()
    QDomElement writeXml( QDomDocument &doc ) const;

  private:
    Keyframes mKeyframes;
    QEasingCurve mEasingCurve;
};

Q_DECLARE_METATYPE( Qgs3DAnimationSettings::Keyframe )

#endif // QGS3DANIMATIONSETTINGS_H
