title: Can't display patches with mplleaflet
body: <p>I'm trying to display a circle of fixed size in a leaflet map. </p>
  
  <p>I tried with <code>.add_artist()</code>(see <a href="https://stackoverflow.com/questions/46305778/plotting-a-circle-in-leaflet-using-add-artist">here</a>) and I'm now trying with <code>.add_patch()</code></p>
  
  <pre><code>import mplleaflet
  import matplotlib.pyplot as plt
  import matplotlib as mpl
  
  fig, ax = plt.subplots()
  x = 2.363561
  y = 48.951918
  r = 20
  circle1 = mpl.patches.Circle((x,y), radius=r)
  circle2= plt.Circle((x, y), r, color='r')
  
  #ax.add_patch(circle1)
  #ax.add_patch(circle2) 
  
  mplleaflet.show(fig=ax.figure)
  </code></pre>
  
  <p>You can try to uncomment one of the two commented lines, it doesn't matter which line is uncommented, same error pops. </p>
  
  <p>Here is the trace I get : </p>
  
  <pre><code>Traceback (most recent call last):
  
    File "&lt;ipython-input-81-1fdd7f4a9d12&gt;", line 16, in &lt;module&gt;
      mplleaflet.show(fig = ax.figure)
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\_display.py", line 180, in show
      save_html(fig, fileobj=f, **kwargs)
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\_display.py", line 131, in save_html
      html = fig_to_html(fig, **kwargs)
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\_display.py", line 84, in fig_to_html
      exporter.run(fig)
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\mplexporter\exporter.py", line 51, in run
      self.crawl_fig(fig)
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\mplexporter\exporter.py", line 118, in crawl_fig
      self.crawl_ax(ax)
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\mplexporter\exporter.py", line 138, in crawl_ax
      self.draw_patch(ax, patch)
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\mplexporter\exporter.py", line 227, in draw_patch
      mplobj=patch)
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\leaflet_renderer.py", line 125, in draw_path
      rings = list(iter_rings(data, pathcodes))
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\mplleaflet\utils.py", line 14, in iter_rings
      raise ValueError('Unrecognized code: {}'.format(code))
  
  ValueError: Unrecognized code: C
  </code></pre>
  
  <p>Any idea on how to solve this ?</p>
  
  <p>===========================</p>
  
  <p><strong>EDIT :</strong> </p>
  
  <p>Just to see what would happen, I tried doing the same thing than <a href="https://github.com/jwass/mplleaflet/issues/40#issuecomment-327276786" rel="nofollow noreferrer">this</a>, which is changing</p>
  
  <pre><code>elif code == 'L': ring.append(point)
  </code></pre>
  
  <p>to</p>
  
  <pre><code>elif code == 'L' or code == 'Z' or code == 'S' or code == 'C': ring.append(point)
  </code></pre>
  
  <p>in <code>mplleaflet\utils.py</code>, line 11 and 12. Here is what I got :</p>
  
  <p><a href="https://i.stack.imgur.com/nFFHD.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nFFHD.png" alt="enter image description here"></a></p>
  
  <p>===========================</p>
  
  <p><strong>EDIT 2 to answer comment</strong></p>
  
  <p><code>mpl.patches.Rectangle</code> and <code>plt.Rectangle</code> show up :</p>
  
  <pre><code>rect1 = mpl.patches.Rectangle((x,y), 1, 1, color = 'r')
  rect2 = plt.Rectangle((x, y), 1, 1, fc='r')
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/jyHg3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jyHg3.png" alt="enter image description here"></a></p>
  
  <p>Which seems to fit with a rectangle of 1 degree in latitude and 1 degree longitude (see <a href="http://drh2.img.digitalriver.com/DRHM/Storefront/Company/digiwis/images/product/detail/fr2_0117.jpg" rel="nofollow noreferrer">here</a>) (maybe ? Seems a bit small).</p>
  
  <p>As for <code>Polygons</code>, well... At least they show up, but I guess there is a projection problem : </p>
  
  <pre><code>regpol1 = mpl.patches.RegularPolygon((x,y), 100, radius=r, color = 'r')
  cirpol1 = mpl.patches.CirclePolygon((x +50,y), radius=r, color = 'b')
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/tDBgM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tDBgM.png" alt="enter image description here"></a></p>