/***********************************************************
             CSC418, SPRING 2005
 
                 light_source.h
                 author: Jack Wang

		light source classes

***********************************************************/

#include "util.h"

// Base class for a light source.  You could define different types
// of lights here, but point light is sufficient for most scenes you
// might want to render.  Different light sources shade the ray 
// differently.
class LightSource {
public:
	virtual void shade( Ray3D& ) = 0;
};

// A point light is defined by its position in world space and its
// colour.
class PointLight : public LightSource {
public:
	PointLight( Point3D pos, Colour col ) : _pos(pos), _col(col) {}
	void shade( Ray3D& ray );
	
private:
	Point3D _pos;
	Colour _col;
};