title: Force square corners on edges with graphviz
body: <p>I have the following <code>.dot</code> file.</p>
  
  <pre><code>digraph
  {
      node [color=Limegreen,fontcolor=Limegreen,shape=oval]
      ilocus [label="iLocus"]
      gilocus [label="giLocus"]
      pilocus [label="piLocus"]
      nilocus [label="niLocus"]
      silocus [label="siLocus"]
      cilocus [label="ciLocus"]
      filocus [label="fiLocus"]
      iilocus [label="iiLocus"]
  
      node [color=Blue,fontcolor=Blue,shape=diamond]
      containgene [label="Contains gene(s)?"]
      proteincoding [label="Protein coding?"]
      multiplegenes [label="Multiple genes?"]
      geneflank [label="Flanked by genes\non both sides?"]
  
      ilocus -&gt; containgene
      containgene:e -&gt; geneflank [xlabel="No"]
      geneflank:e -&gt; filocus [xlabel="No"]
      geneflank:w -&gt; iilocus [xlabel="Yes"]
      containgene:w -&gt; gilocus [xlabel="Yes"]
      gilocus -&gt; proteincoding
      proteincoding:e -&gt; nilocus [xlabel="No"]
      proteincoding:w -&gt; pilocus [xlabel="Yes"]
      pilocus -&gt; multiplegenes
      multiplegenes:e -&gt; silocus [xlabel="No"]
      multiplegenes:w -&gt; cilocus [xlabel="Yes"]
  }
  </code></pre>
  
  <p>Rendering with graphviz I get the following.</p>
  
  <p><a href="https://i.stack.imgur.com/Pghf9.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Pghf9.png" alt="Graphviz take 1"></a></p>
  
  <p>Is there any way I can force the edges to have square corners rather than rounded corners? The <code>splines=ortho</code> attribute from the documentation seems to be designed for this in principle, but in practice I just get straight lines when I add <code>graph [splines=ortho]</code> to my digraph.</p>
  
  <p><a href="https://i.stack.imgur.com/eo4Fw.png" rel="noreferrer"><img src="https://i.stack.imgur.com/eo4Fw.png" alt="Graphviz take 2"></a></p>
  
  <p>Any way I can get square corners on the edges with graphviz? Something like the following:</p>
  
  <pre><code>  ------ Multiple genes? -----
    |                          |
    | N                      Y |
    |                          |
    v                          V
  siLocus                   ciLocus
  </code></pre>