/* -----------------------------------------------------------------------------
	GSFramework
	Copyright 2001-2013 Emmanuel Julien. All Rights Reserved.
----------------------------------------------------------------------------- */


#ifndef	__NPLANE__
#define	__NPLANE__


		#include "math/vector.h"


namespace GS {

/*!
	@short	Plane.
	ax + by + cz + d = 0
	@author	Emmanuel Julien (ejulien@nworks.fr)
*/

class	Plane
{
		float			d;						///< Distance to origin.
		Vector4			p, n;					///< Point in plane and normal.

public:

		/// Return plane normal.
inline	const Vector4	&GetNormal() const
		{	return n;	}

		/*!
			@short	Return point distance to plane.

			Distance is signed, positive when the point is in front of the plane,
			negative otherwise.
		*/
inline	float			DistanceToPlane(const Vector4 &p) const
		{	return p.Dot(n) + d;	}

		/// Set plane from point/normal and an optional transformation matrix.
		void			Set(const Vector4 *_p, const Vector4 &_n, const Matrix4 * = 0);
		/// Set plane three vectors and an optional transformation matrix.
		void			Set(const Vector4 _p[3], const Matrix4 * = 0);

		Plane();
		Plane(const Vector4 &_p, const Vector4 &_n, const Matrix4 *_m = 0)
		{	Set(&_p, _n, _m);	}
};

} // GS


#endif	// __NPLANE__