Add experimental SVG converter

Author: sseemayer

py2d/SVG.py

@@ -0,0 +1,124 @@
+"""SVG to Polygon conversion
+
+This is still experimental code and only a tiny subset of SVG is supported. Things that are NOT supported:
+
+	- open line segments
+	- curves of any kind
+
+Testing files were generated using Inkscape. Make sure to use "Make selected nodes corner" on all polygons to be converted so they contain no problematic SVG path commands!
+"""
+
+from xml.etree import ElementTree
+import re
+import warnings
+from collections import deque
+from Math import Polygon, Vector, Transform
+
+def convert_svg(f, transform=Transform.unit()):
+	"""Convert an SVG file to a hash of Py2D Polygons. 
+
+	The hash keys will be the ids set to the corresponding <path> elements in the SVG file. 
+	The hash value is a list of polygons, the first one being the outline polygon and all additional polygons being holes.
+
+	@param f: File object or file name to a SVG file.
+
+	@type transform: Transform
+	@param transform: A transformation to apply to all polygons
+	"""
+
+	svg_ns = "http://www.w3.org/2000/svg"
+	et = ElementTree.parse(f)
+
+	def transform_element(e, transform):
+		new_t = e.get("transform", "")
+
+		nt = transform
+		m = re.match(r'translate\((?P<x>[0-9.-]+),(?P<y>[0-9.-]+)\)', new_t)
+		if m:
+			x, y = float(m.group("x")), float(m.group("y"))
+			nt = Transform.move(x,y) * transform 
+
+		return nt
+
+	def path_find(e, transform=Transform.unit()):
+		"""Generator function to recursively list all paths under an element e"""
+
+		# yield path nodes within current element
+		for p in e.iterfind("{%s}path" % svg_ns):
+			yield (p, transform_element(p, transform))
+
+		# yield path nodes in subgroups
+		for g in e.iterfind("{%s}g" % svg_ns):
+			for p,t in path_find(g, transform_element(g, transform)):
+				yield (p, t)
+
+
+	def convert_element(e, transform):
+		"""Convert an SVG path element to one or multiple Py2D polygons."""
+
+		# get data from the <path> element
+		id = e.get("id")
+		d = e.get("d")
+
+		#print "CONVERTING %s: %s" % (id, d)
+
+		def parse_commands(draw_commands):
+			"""Generator Function to parse a SVG draw command sequence into command and parameter tuples"""
+			tokens = draw_commands.split(" ")
+			while tokens:
+				# find the next token that is a command
+				par_index = next( i for i,v in enumerate(tokens[1:] + ["E"]) if re.match('^[a-zA-Z]$', v) ) + 1
+			
+				# first token should always be the command, rest the parameters
+				cmd = tokens[0]
+				pars = tokens[1:par_index]
+
+				# remove the parsed tokens
+				del tokens[:par_index]
+
+				yield cmd, pars
+
+		def parse_vec(s):
+			x,y = s.split(",")
+			return Vector(float(x), float(y))
+
+		polys = []
+		verts = []
+		relative_pos = Vector(0.0,0.0)
+		for cmd, pars in parse_commands(d):
+
+			#print "cmd: %s, pars: %s" % (cmd, pars)
+
+			if cmd == "m":
+
+				for p in pars:
+					relative_pos += parse_vec(p)
+					verts.append(relative_pos)
+
+			elif cmd == "z":
+				# close line by only moving relative_pos to first vertex
+				
+				polys.append(transform * Polygon.from_pointlist(verts))
+				relative_pos = verts[0]
+				verts = []
+
+				pass
+
+			else:
+				warnings.warn("Unrecognized SVG path command: %s - path skipped" % cmd)
+				polys = []
+				break
+			
+		#print "----"
+
+		return id, polys
+
+	out = {}
+	for p,tr in path_find(et.getroot(), transform):
+		id, polys = convert_element(p,tr)
+		out[id] = polys
+
+	return out
+
+if __name__ == "__main__":
+	print convert_svg("py2d/examples/shapes.svg")

py2d/examples/SVG.py

@@ -0,0 +1,50 @@
+import pygame
+from pygame.locals import *
+
+from py2d.Math import *
+from py2d.SVG import convert_svg
+
+import py2d.examples.Main
+
+class SVGConverter(py2d.examples.Main.Example):
+	"""SVG Converter Sample
+
+	Polygons are imported from an SVG file created in Inkscape.
+
+	Have fun!
+	"""
+	def __init__(self, runner):
+		self.runner = runner
+		self.title = "Polygon Decomposition"
+
+		self.polys = []
+
+		for id, polys in convert_svg("py2d/examples/shapes.svg").iteritems():
+			self.polys.append(polys)
+
+		self.decomp = []
+
+		self.poly_colors = [ 0xff0000, 0x00ff00, 0x0000ff, 0xffff00, 0xff00ff, 0x00ffff ]
+
+		print self.polys
+
+
+	def render(self):
+
+		t = Transform.unit() #Transform.move(-22,-700)
+
+		for j, p in enumerate(self.polys):
+			for i,h in enumerate(p):
+				self.draw_poly(t * h, self.poly_colors[j % len(self.poly_colors)], False)
+
+
+	def draw_poly(self, poly, color, fill):
+		if len(poly) > 1:
+			if fill and len(poly) > 2:
+				pygame.draw.polygon(self.runner.screen, color, poly.as_tuple_list())
+			
+			pygame.draw.lines(self.runner.screen, color, True, poly.as_tuple_list())
+		elif poly.points:
+			pygame.draw.circle(self.runner.screen, color, poly.points[0].as_tuple(), 2)
+
+