Cleanup Firefox SVG example.

In the SVG parser: simplify the regexes; do not drop "z" codes (they
were previously dropped because they are immediately followed by another
code, and thus did not match `path_re`; things only worked because the
SVG source was careful to explicitly move back to the start point before
issuing CLOSEPOLYs) but instead include them explicitly.

Don't rely on later in-place modification of `verts` propagating back to
`path`, but modify it first.

Make the figure background gray (as was the case for the classic style);
that makes the white outline visible again (otherwise that white outline
doesn't really make sense).  Also just generally compress the rest of
the code down.

Author: anntzer

examples/showcase/firefox.py

@@ -22,50 +22,38 @@ def svg_parse(path):
                 'Q': (Path.CURVE3,)*2,
                 'C': (Path.CURVE4,)*3,
                 'Z': (Path.CLOSEPOLY,)}
-    path_re = re.compile(r'([MLHVCSQTAZ])([^MLHVCSQTAZ]+)', re.IGNORECASE)
-    float_re = re.compile(r'(?:[\s,]*)([+-]?\d+(?:\.\d+)?)')
     vertices = []
     codes = []
-    last = (0, 0)
-    for cmd, values in path_re.findall(path):
-        points = [float(v) for v in float_re.findall(values)]
-        points = np.array(points).reshape((len(points)//2, 2))
+    cmd_values = re.split("([A-Za-z])", path)[1:]  # Split over commands.
+    for cmd, values in zip(cmd_values[::2], cmd_values[1::2]):
+        # Numbers are separated either by commas, or by +/- signs (but not at
+        # the beginning of the string).
+        points = ([*map(float, re.split(",|(?<!^)(?=[+-])", values))] if values
+                  else [(0., 0.)])  # Only for "z/Z" (CLOSEPOLY).
+        points = np.reshape(points, (-1, 2))
         if cmd.islower():
-            points += last
-        cmd = cmd.capitalize()
-        last = points[-1]
-        codes.extend(commands[cmd])
-        vertices.extend(points.tolist())
-    return codes, vertices
+            points += vertices[-1][-1]
+        codes.extend(commands[cmd.upper()])
+        vertices.append(points)
+    return np.array(codes), np.concatenate(vertices)
 
-# SVG to matplotlib
+
+# SVG to Matplotlib
 codes, verts = svg_parse(firefox)
-verts = np.array(verts)
 path = Path(verts, codes)
 
-# Make upside down
-verts[:, 1] *= -1
-xmin, xmax = verts[:, 0].min()-1, verts[:, 0].max()+1
-ymin, ymax = verts[:, 1].min()-1, verts[:, 1].max()+1
+xmin, ymin = verts.min(axis=0) - 1
+xmax, ymax = verts.max(axis=0) + 1
 
-fig = plt.figure(figsize=(5, 5))
-ax = fig.add_axes([0.0, 0.0, 1.0, 1.0], frameon=False, aspect=1)
+fig = plt.figure(figsize=(5, 5), facecolor="0.75")  # gray background
+ax = fig.add_axes([0, 0, 1, 1], frameon=False, aspect=1,
+                  xlim=(xmin, xmax),  # centering
+                  ylim=(ymax, ymin),  # centering, upside down
+                  xticks=[], yticks=[])  # no ticks
 
 # White outline (width = 6)
-patch = patches.PathPatch(path, facecolor='None', edgecolor='w', lw=6)
-ax.add_patch(patch)
-
+ax.add_patch(patches.PathPatch(path, facecolor='none', edgecolor='w', lw=6))
 # Actual shape with black outline
-patch = patches.PathPatch(path, facecolor='orange', edgecolor='k', lw=2)
-ax.add_patch(patch)
-
-# Centering
-ax.set_xlim(xmin, xmax)
-ax.set_ylim(ymin, ymax)
-
-# No ticks
-ax.set_xticks([])
-ax.set_yticks([])
+ax.add_patch(patches.PathPatch(path, facecolor='orange', edgecolor='k', lw=2))
 
-# Display
-plt.show()
+plt.show()  # Display