LinkShape2D[pts,r,type] function defines a 2D link-shape primitive by generating a poly-line link shape through the points pts. The radius of the head and tail of the link r. The type of the link are 'RR', 'RT', 'TR', 'TT'.
LinkShape function generates a chain of points of the 2D shape.
The type information is specifying the start and ending form of the link shape. The 'R' type specifies a hinge type ending while the 'T' type result a flat ending.
If a poly-line is specified the internal break points always have a hinge type geometry.