[Tex/LaTex] arrow tip when using “.. controls ..” in tikz

Question

When I draw a commutative diagram with tikz, I normally use the syntax

\documentclass{article}
\usepackage{tikz}

\begin{document}

\begin{center}
\begin{tikzpicture}
\node (a) at (0,0) {$A$};
\node (b) at (2,0) {$B$};
\node (c) at (4,0) {$C$};
\path[->]
(a) edge (b)
(b) edge (c)
(a) edge [bend left] (c)
(a) edge [bend right] (c);
\end{tikzpicture}
\end{center}

\end{document}

This time, due to the size of the nodes, I need to use .. controls (2,2) .. to make the arrows avoid the nodes. But when I type

\begin{center}
\begin{tikzpicture}
\node (a) at (0,0) {$A$};
\node (b) at (2,0) {$B$};
\node (c) at (4,0) {$C$};
\draw[->]
(a) edge (b)
(b) edge (c)
(a) .. controls (2,2) ..  (c)
(a) .. controls (2,-2) .. (c);
\end{tikzpicture}
\end{center}

the arrow tip appears only at the last line drawn using the controls syntax (and at the two edges). How can I specify that I want an arrow tip at every line?

Answer 1

You can use arrows.meta library and looseness key to control the distance from the control point to the two end points as said in the pgfmanual.

\documentclass{beamer}

\usepackage{tikz}
\usetikzlibrary{arrows.meta}
\usepackage[tightpage,active]{preview}
\PreviewEnvironment{tikzpicture}

\begin{document}
\begin{center}
\begin{tikzpicture}
\node (a) at (0,0) {$A$};
\node (b) at (2,0) {$B$};
\node (c) at (4,0) {$C$};

\path[->]
(a) edge (b)
(b) edge (c)
(a) edge [out=80,in=100,looseness=5] (c)
(a) edge [out=-55,in=-125,looseness=1.5] (c);
\end{tikzpicture}

\end{center}
\end{document}