/*	Public domain	*/

__BEGIN_DECLS
M_Line2	M_LineRead2(AG_DataSource *_Nonnull);
M_Line3	M_LineRead3(AG_DataSource *_Nonnull);
void	M_LineWrite2(AG_DataSource *_Nonnull, M_Line2 *_Nonnull);
void	M_LineWrite3(AG_DataSource *_Nonnull, M_Line3 *_Nonnull);

M_Line2 M_LineFromPtDir2(M_Vector2, M_Vector2, M_Real);
M_Line3	M_LineFromPtDir3(M_Vector3, M_Vector3, M_Real);
M_Line2	M_LineFromPts2(M_Vector2, M_Vector2);
M_Line3	M_LineFromPts3(M_Vector3, M_Vector3);
M_Line2	M_LineProject2(M_Line3);
M_Line3	M_LineProject3(M_Line2);
M_Line2	M_LineParallel2(M_Line2, M_Real);
M_Line3	M_LineParallel3(M_Line3, M_Real);

M_Real	M_LinePointDistance2(M_Line2, M_Vector2);
M_Real	M_LinePointDistance3(M_Line3, M_Vector3);
M_Real	M_LineLineAngle2(M_Line2, M_Line2);
M_Real	M_LineLineAngle3(M_Line3, M_Line3);
int     M_LineLineShortest3(M_Line3, M_Line3, M_Line3 *_Nullable);

M_GeomSet2 M_IntersectLineLine2(M_Line2, M_Line2);

/* Return the two-point representation of the given line in R2. */
static __inline__ void
M_LineToPts2(M_Line2 L, M_Vector2 *_Nonnull p1, M_Vector2 *_Nonnull p2)
{
	*p1 = L.p;
	*p2 = M_VecAdd2(L.p, M_VecScale2p(&L.d, L.t));
}

/* Return the two-point representation of the given line in R3. */
static __inline__ void
M_LineToPts3(M_Line3 L, M_Vector3 *_Nonnull p1, M_Vector3 *_Nonnull p2)
{
	*p1 = L.p;
	*p2 = M_VecAdd3(L.p, M_VecScale3p(&L.d, L.t));
}

/* Test whether the given Line is actually a ray. */
static __inline__ int
M_LineIsRay2(M_Line2 L)
{
	return (L.t == M_INFINITY);
}
static __inline__ int
M_LineIsRay3(M_Line3 L)
{
	return (L.t == M_INFINITY);
}

/* Return the first and second Points of the given Line. */
static __inline__ M_Vector2
M_LineInitPt2(M_Line2 L)
{
	return (L.p);
}
static __inline__ M_Vector2
M_LineTermPt2(M_Line2 L)
{
	return M_VecAdd2(L.p, M_VecScale2p(&L.d, L.t));
}
static __inline__ M_Vector3
M_LineInitPt3(M_Line3 L)
{
	return (L.p);
}
static __inline__ M_Vector3
M_LineTermPt3(M_Line3 L)
{
	return M_VecAdd3(L.p, M_VecScale3p(&L.d, L.t));
}

/* Test whether the given Point is left/on/right of an ideal line. */
static __inline__ M_Real
M_LinePointSide2(M_Line2 L, M_Vector2 p)
{
	M_Vector2 p1, p2;
	
	M_LineToPts2(L, &p1, &p2);
	return (p2.x - p1.x)*(p.y - p1.y) - (p.x - p1.x)*(p2.y - p1.y);
}
__END_DECLS