matrix4 cMatrix4::Inverted()
{
    matrix4 a;
    point3 p(_41,_42,_43);
	    float x=p*point3(_11,_12,_13);
    float y=p*point3(_21,_22,_23);
    float z=p*point3(_31,_32,_33);

    return matrix4( _11, _21, _31, 0.f,
					_12, _22, _32, 0.f,
					_13, _23, _33, 0.f,
					 -x,  -y,  -z, 1.f);
}

float operator*(point3 const &a, point3 const &b)
{
    return a.x*b.x+a.y*b.y+a.z*b.z;
}

typedef class cMatrix4
{
public:
	union
	{
		float m[4][4];
		struct
		{
			float _11, _12, _13, _14,
				  _21, _22, _23, _24,
				  _31, _32, _33, _34,
				  _41, _42, _43, _44;
		};
	};

	cMatrix4( float n11,float n12,float n13,float n14,
			  float n21,float n22,float n23,float n24,
			  float n31,float n32,float n33,float n34,
			  float n41,float n42,float n43,float n44)
	{
		m[0][0]=n11; m[0][1]=n12; m[0][2]=n13; m[0][3]=n14;
		m[1][0]=n21; m[1][1]=n22; m[1][2]=n23; m[1][3]=n24; 
		m[2][0]=n31; m[2][1]=n32; m[2][2]=n33; m[2][3]=n34; 
		m[3][0]=n41; m[3][1]=n42; m[3][2]=n43; m[3][3]=n44; 
	}
} matrix4;