fixed svg2path parsing of svg-polygon elements with redundant closure points

setup.py

@@ -3,7 +3,7 @@ import codecs
 import os
 
 
-VERSION = '1.3.1'
+VERSION = '1.3.2beta'
 AUTHOR_NAME = 'Andy Port'
 AUTHOR_EMAIL = 'AndyAPort@gmail.com'
 

svgpathtools/svg2paths.py

@@ -12,16 +12,13 @@ from .parser import parse_path
 
 
 def polyline2pathd(polyline_d):
-    """converts the string from a polyline d-attribute to a string for a Path
-    object d-attribute"""
+    """converts the string from a polyline points-attribute to a string for a 
+    Path object d-attribute"""
     points = polyline_d.replace(', ', ',')
     points = points.replace(' ,', ',')
     points = points.split()
 
-    if points[0] == points[-1]:
-        closed = True
-    else:
-        closed = False
+    closed = points[0] == points[-1]
 
     d = 'M' + points.pop(0).replace(',', ' ')
     for p in points:
@@ -31,6 +28,30 @@ def polyline2pathd(polyline_d):
     return d
 
 
+def polygon2pathd(polyline_d):
+    """converts the string from a polygon points-attribute to a string for a 
+    Path object d-attribute.
+    Note:  For a polygon made from n points, the resulting path will be 
+    composed of n lines (even if some of these lines have length zero)."""
+    points = polyline_d.replace(', ', ',')
+    points = points.replace(' ,', ',')
+    points = points.split()
+
+    reduntantly_closed = points[0] == points[-1]
+
+    d = 'M' + points[0].replace(',', ' ')
+    for p in points[1:]:
+        d += 'L' + p.replace(',', ' ')
+    
+    # The `parse_path` call ignores redundant 'z' (closure) commands
+    # e.g. `parse_path('M0 0L100 100Z') == parse_path('M0 0L100 100L0 0Z')`
+    # This check ensures that an n-point polygon is converted to an n-Line path.
+    if reduntantly_closed:
+        d += 'L' + points[0].replace(',', ' ')
+
+    return d + 'z'
+
+
 def svg2paths(svg_file_location,
               convert_lines_to_paths=True,
               convert_polylines_to_paths=True,
@@ -87,7 +108,7 @@ def svg2paths(svg_file_location,
     # path strings, add to list
     if convert_polygons_to_paths:
         pgons = [dom2dict(el) for el in doc.getElementsByTagName('polygon')]
-        d_strings += [polyline2pathd(pg['points']) + 'z' for pg in pgons]
+        d_strings += [polygon2pathd(pg['points']) for pg in pgons]
         attribute_dictionary_list += pgons
 
     if convert_lines_to_paths:

test/polygons.svg

@@ -0,0 +1,5 @@
+<?xml version="1.0" ?>
+<svg baseProfile="full" height="600px" version="1.1" viewBox="-10.05 -10.05 120.1 120.1" width="600px" xmlns="http://www.w3.org/2000/svg" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <polygon points="55.5,0 55.5, 50 105.5,50" style="stroke:purple;stroke-width:1"/>
+  <polygon points="0,0 0,100 100,100 0,0" style="stroke:purple;stroke-width:1"/>
+</svg>

test/test_svg2paths.py

@@ -0,0 +1,30 @@
+from __future__ import division, absolute_import, print_function
+import unittest
+from svgpathtools import *
+from os.path import join, dirname
+
+class TestSVG2Paths(unittest.TestCase):
+    def test_svg2paths_polygons(self):
+
+        paths, _ = svg2paths(join(dirname(__file__), 'polygons.svg'))
+
+        # triangular polygon test
+        path = paths[0]
+        path_correct = Path(Line(55.5+0j, 55.5+50j), 
+                            Line(55.5+50j, 105.5+50j), 
+                            Line(105.5+50j, 55.5+0j)
+                            )
+        self.assertTrue(path.isclosed())
+        self.assertTrue(len(path)==3)
+        self.assertTrue(path==path_correct)
+
+        # triangular quadrilateral (with a redundant 4th "closure" point)
+        path = paths[1]
+        path_correct = Path(Line(0+0j, 0+100j),
+                            Line(0+100j, 100+100j),
+                            Line(100+100j, 0+0j),
+                            Line(0+0j, 0+0j)  # result of redundant point
+                            )
+        self.assertTrue(path.isclosed())
+        self.assertTrue(len(path)==4)
+        self.assertTrue(path==path_correct)