main/src/georegression/geometry/UtilLine2D_F64.java
public static LineParametric2D_F64 convert( Point2D_F64 a , Point2D_F64 b , LineParametric2D_F64 ret )
	{
		if( ret == null )
			ret = new LineParametric2D_F64();

		ret.p.set(a);
		ret.slope.x = b.x-a.x;
		ret.slope.y = b.y-a.y;

		return ret;
	}
public static LineParametric2D_F64 convert( Point2D_F64 a , Point2D_F64 b , LineParametric2D_F64 ret )
	{
		if( ret == null )
			ret = new LineParametric2D_F64();

		ret.p.set(a);
		ret.slope.x = b.x-a.x;
		ret.slope.y = b.y-a.y;

		return ret;
	}
public static LineParametric2D_F64 convert ( Point2D_F64 a , Point2D_F64 b , LineParametric2D_F64 ret ) { if ( ret == null ) ret = new LineParametric2D_F64 ( ) ; ret . p . set ( a ) ; ret . slope . x = b . x - a . x ; ret . slope . y = b . y - a . y ; return ret ; }
Converts a line segment into a line in parametric format. It will point from a to b. Point a and b must
be unique.

@param a (Input) End point of line segment
@param b (Input) End point of line segment
@param ret (output) Storage for new line.. If null a new instance will be created.
@return The resulting line
Converts a line segment into a line in parametric format . It will point from a to b . Point a and b must be unique .