特定的环形箭头

Question

目标如下：

这是我目前的情况。我知道如何制作弯曲的箭，但不知道弯曲的箭那远或那...具体来说，我猜？

\tikzstyle{allocated} = [>=latex, thick, <-, shorten <=2pt, shorten >=2pt]
\tikzstyle{requested} = [>=latex, thick, ->, shorten >=2pt, shorten <=2pt, dashed]
\tikzstyle{process} = [circle, fill=gray!30]
\tikzstyle{resource} = [fill=cyan!30,
                            minimum width=1cm,
                            minimum height=0.7cm]

\begin{tikzpicture}
    \node[draw, resource] at (0, 0)   (r1) {};
        \node[anchor=south] at (r1.north) {$R_1$};
    \node[draw, resource] at (4, 0)   (r2) {};
        \node[anchor=south] at (r2.north) {$R_2$};

    \node[draw, process] at (0, -2)   (t1) {$T_1$};
    \node[draw, process] at (2, -2)   (t2) {$T_2$};
    \node[draw, process] at (4, -2)   (t3) {$T_3$};

    \path[allocated]
        (t2) edge (r1)
        (t2) edge (r2)
        (t3) edge (r2);

    \path[requested]
        (t1) edge (r1);
\end{tikzpicture}

（您可能会注意到，这里有两种箭头，虚线和实线，在图中看不到。那是因为我试图使差异更加直观，因为我觉得这很令人困惑。）

Answer 1

你可以试试controls，嗯

\tikzstyle{allocated} = [>=latex, thick, <-, shorten <=2pt, shorten >=2pt]
\tikzstyle{requested} = [>=latex, thick, ->, shorten >=2pt, shorten <=2pt, dashed]
\tikzstyle{process} = [circle, fill=gray!30]
\tikzstyle{resource} = [fill=cyan!30,
                            minimum width=1cm,
                            minimum height=0.7cm]

\begin{tikzpicture}
    \node[draw, resource] at (0, 0)   (r1) {};
        \node[anchor=south] at (r1.north) {$R_1$};
    \node[draw, resource] at (4, 0)   (r2) {};
        \node[anchor=south] at (r2.north) {$R_2$};

    \node[draw, process] at (0, -2)   (t1) {$T_1$};
    \node[draw, process] at (2, -2)   (t2) {$T_2$};
    \node[draw, process] at (4, -2)   (t3) {$T_3$};

    \path[allocated]
        (t2) edge (r1)
        (t2) edge (r2)
        (t3) edge (r2);

    \path[requested]
        (t1) edge (r1);

    \draw[allocated] (t3) ..controls(5.5,1.5).. (r1);
    \draw[allocated] (r2) ..controls(2,-3.5).. (t1);
\end{tikzpicture}

这是一个解决方案，但可能不是最好的。