# How to adjust the arrow head tip of a bezier curve?

I want to adjust the arrow head tip of a bezier curve on the left such that it looks like the one on the right.

As there is no \ncbezier or \pcbezier available, I cannot use nodesep to adjust it. arcsep does not work as well.

Using \psbezier{->}([offset=4pt]R)([offset=-4pt]CR)([offset=-4pt]CL)([offset=4pt]L) is not perfect because it produces a new different bezier curve. In the right figure, can you see the filled region bounded by the first created bezier curve is not exactly enclosed by the second one?

\documentclass[border=12pt]{standalone}
\usepackage{pst-node}

\def\Common{%
% define nodes
\pnode(0,0){L}
\pnode(1;45){T}
\pnode(!2 sqrt 0){R}
\pnode[-0.5,0.75](T){CL}
\pnode[0.5,0.75](T){CR}
% draw a bezier curve
\pscustom[fillstyle=solid,fillcolor=red,linestyle=none]{\psbezier(R)(CR)(CL)(L)\closepath}
% draw dots
\pscircle(L){4pt}
\pscircle(R){4pt}
}

\begin{document}
\begin{pspicture}[showgrid=false](1.45,1.25)
\Common
\psbezier{->}(R)(CR)(CL)(L)
\end{pspicture}
\begin{pspicture}[showgrid=false](1.45,1.25)
\Common
\psbezier{->}([offset=4pt]R)([offset=-4pt]CR)([offset=-4pt]CL)([offset=4pt]L)
\end{pspicture}
\end{document}


So how to adjust it? More general question: Is it possible to put the arrow head to any point on the path (as in TikZ it is possible)?

-
I don't know pstricks, but Metapost handles this as follows. Save the original path, shorten it by the required amount (by using metapost primitives that allow you to traverse a certain distance on the path) and then draw the arrow. The same idea should work in pstricks as well. – Aditya Mar 31 '13 at 19:47
@Karl's students Herbert has come up with a solution at tug.org/PSTricks/Examples/Gallery/exa070.tex. – Svend Tveskæg Apr 3 '13 at 0:13
@SvendMortensen: You can make it as your answer and I will accept it to finalize the bounty and question. – kiss my armpit Apr 3 '13 at 0:33
Okay, but I haven't really done anything, I think. :) – Svend Tveskæg Apr 3 '13 at 0:36