Light.h

/**
@file Light.h
@author JOL
*/
#pragma once
#ifndef _LIGHT_H_
#define _LIGHT_H_

// In order to call opengl commands in all graphical objects
#include "Viewer.h"
#include "PointVector.h"

/// Namespace RayTracer
namespace rt {

  /// Lights are used to give lights in a scene.
  struct Light {

    /// Default constructor. Nothing to do.
    Light() {}

    /// Virtual destructor since object contains virtual methods.
    virtual ~Light() {}
    
    /// This method is called by Scene::init() at the beginning of the
    /// display in the OpenGL window.
    virtual void init( Viewer& /* viewer */ ) = 0;

    /// This method is called by Scene::light() at each frame to
    /// set the lights in the OpenGL window.
    virtual void light( Viewer& /* viewer */ ) = 0;

    /// This method is called by Scene::draw() at each frame to
    /// redisplay objects in the OpenGL window.
    virtual void draw( Viewer& /* viewer */) = 0;

    /// Given the point \a p, returns the normalized direction to this
    /// light.
    virtual Vector3 direction( const Vector3& /* p */ ) const = 0;

    /// @return the color of this light viewed from the given point \a
    /// p.
    virtual Color color( const Vector3& /* p */ ) const = 0;

  };

} // namespace rt

#endif // #define _LIGHT_H_