/*! 
    \file light.h
    \brief Handles Lights.

    A Light is one of the more important things in a 3D-environment,
    without it one sees nothing :)
    It is here for diffuse-, specular- and Bump-Mappings.
*/

#ifndef _LIGHT_H
#define _LIGHT_H

#include "world_entity.h"
#include "glincl.h"

#define NUMBEROFLIGHTS GL_MAX_LIGHTS

enum AttenuationType {CONSTANT, LINEAR, QUADRATIC};

// FORWARD DEFINITIONS //
class Vector;

//! A class that handles Lights
/**
   A Light is a source that emits light rays (photons)
*/
class Light : public WorldEntity
{
 private:
  //! A struct that holds information about a Light
  struct LightValue
  {
    int lightNumber;            //!< The number of this Light.
    GLfloat lightPosition[4];   //!< The Position of this Light.
    GLfloat lmodelAmbient[4];   //!< The general Ambient Color.
    GLfloat diffuseColor[4];    //!< The Diffuse Color this Light emmits.
    GLfloat specularColor[4];   //!< The specular Color of this Light.
    AttenuationType attenuationType;//!< The AttenuationType of this Light.
    float attenuationFactor;    //!< the Factor the attenuation should have.

    LightValue* next;
  };

  static Light* singletonRef;    //!< This is the LightHandlers Reference.
  GLfloat ambientColor[4];       //!< The ambient Color of the scene.


  Light(void);

  void init(int LightNumber);  
  LightValue** lights;
  LightValue* currentLight;
  
 public:
  static Light* getInstance();
  ~Light(void);

  // set Attributes
  int addLight(void);
  int addLight(int lightNumber);
  void editLightNumber(int lightNumber);
  void deleteLight(void);
  void deleteLight(int lightNumber);

  void setPosition(Vector position);
  void setPosition(GLfloat x, GLfloat y, GLfloat z);
  void setDiffuseColor(GLfloat r, GLfloat g, GLfloat b);
  void setSpecularColor(GLfloat r, GLfloat g, GLfloat b);
  void setAttenuation(AttenuationType type, float factor);
  void setAmbientColor(GLfloat r, GLfloat g, GLfloat b);
  // get Attributes
  Vector getPosition(void);
};

#endif /* _LIGHT_H */