/*!
 * @file camera.h
 * Viewpoint controlling class definitions
*/

#ifndef _CAMERA_H
#define _CAMERA_H

#include "p_node.h"
#include "event_listener.h"
#include "plane.h"

class World;
class CameraTarget;
class Event;

//! an enumerator for different types of view
typedef enum ViewMode
{
  VIEW_NORMAL,
  VIEW_BEHIND,
  VIEW_FRONT,
  VIEW_LEFT,
  VIEW_RIGHT,
  VIEW_TOP
};

//! Camera
/**
 * This class controls the viewpoint from which the World is rendered.
*/
class Camera : public PNode, public EventListener
{
 public:
  Camera();
  virtual ~Camera();

  void lookAt(PNode* target);
  CameraTarget* getTarget() const { return this->target; };
  PNode* getTargetNode() const;

  void setAspectRatio(float aspectRatio);
  void setFovy(float fovy);
  void setClipRegion(float nearClip, float farClip);

  void setViewMode(ViewMode mode);
  inline const Vector& getViewVector() const { return this->viewVector; }
  inline const Vector& getUpVector() const { return this->upVector; }
  inline const Plane& getViewFrustum() const { return this->frustumPlane; }

  inline float distance(const Vector& distance) const { return this->frustumPlane.distancePoint(distance); }
  inline float distance(const PNode* node) const { return distance(node->getAbsCoor()); }

  void tick(float dt);
  void apply ();

  void process(const Event &event);

 private:
  CameraTarget*     target;          //!< The Target of the Camera (where this Camera Looks at)

  float             fovy;            //!< The field of view Angle (in degrees).
  float             aspectRatio;     //!< The aspect ratio (width / height).
  float             nearClip;        //!< The near clipping plane.
  float             farClip;         //!< The far clipping plane.

  float             toFovy;          //!< The fovy-mode to iterate to.
  ViewMode          currentMode;     //!< The ViewMode the camera is in

  Vector            delay;
  Plane             frustumPlane;    //!< plane that marks the view frustum
  Vector            viewVector;      //!< the direction of the camera view
  Vector            upVector;        //!< direction of the up vector
};

//! A CameraTarget is where the Camera is looking at.
class CameraTarget : public PNode
{
  friend class Camera;             //! The CameraTarget is a friend of Camera. noone else needs a CameraTarget, so noone else can create it.

 private:
  CameraTarget();

 public:
};


#endif /* _CAMERA_H */