184 lines
		
	
	
		
			5.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			184 lines
		
	
	
		
			5.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| import re
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| 
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| 
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| def _prefer_non_zero(*args):
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|     for arg in args:
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|         if arg != 0:
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|             return arg
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|     return 0.0
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| 
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| 
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| def _ntos(n):
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|     # %f likes to add unnecessary 0's, %g isn't consistent about # decimals
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|     return ("%.3f" % n).rstrip("0").rstrip(".")
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| 
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| 
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| def _strip_xml_ns(tag):
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|     # ElementTree API doesn't provide a way to ignore XML namespaces in tags
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|     # so we here strip them ourselves: cf. https://bugs.python.org/issue18304
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|     return tag.split("}", 1)[1] if "}" in tag else tag
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| 
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| 
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| def _transform(raw_value):
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|     # TODO assumes a 'matrix' transform.
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|     # No other transform functions are supported at the moment.
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|     # https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/transform
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|     # start simple: if you aren't exactly matrix(...) then no love
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|     match = re.match(r"matrix\((.*)\)", raw_value)
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|     if not match:
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|         raise NotImplementedError
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|     matrix = tuple(float(p) for p in re.split(r"\s+|,", match.group(1)))
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|     if len(matrix) != 6:
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|         raise ValueError("wrong # of terms in %s" % raw_value)
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|     return matrix
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| 
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| 
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| class PathBuilder(object):
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|     def __init__(self):
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|         self.paths = []
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|         self.transforms = []
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| 
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|     def _start_path(self, initial_path=""):
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|         self.paths.append(initial_path)
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|         self.transforms.append(None)
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| 
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|     def _end_path(self):
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|         self._add("z")
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| 
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|     def _add(self, path_snippet):
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|         path = self.paths[-1]
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|         if path:
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|             path += " " + path_snippet
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|         else:
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|             path = path_snippet
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|         self.paths[-1] = path
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| 
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|     def _move(self, c, x, y):
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|         self._add("%s%s,%s" % (c, _ntos(x), _ntos(y)))
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| 
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|     def M(self, x, y):
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|         self._move("M", x, y)
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| 
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|     def m(self, x, y):
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|         self._move("m", x, y)
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| 
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|     def _arc(self, c, rx, ry, x, y, large_arc):
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|         self._add(
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|             "%s%s,%s 0 %d 1 %s,%s"
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|             % (c, _ntos(rx), _ntos(ry), large_arc, _ntos(x), _ntos(y))
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|         )
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| 
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|     def A(self, rx, ry, x, y, large_arc=0):
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|         self._arc("A", rx, ry, x, y, large_arc)
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| 
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|     def a(self, rx, ry, x, y, large_arc=0):
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|         self._arc("a", rx, ry, x, y, large_arc)
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| 
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|     def _vhline(self, c, x):
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|         self._add("%s%s" % (c, _ntos(x)))
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| 
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|     def H(self, x):
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|         self._vhline("H", x)
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| 
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|     def h(self, x):
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|         self._vhline("h", x)
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| 
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|     def V(self, y):
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|         self._vhline("V", y)
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| 
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|     def v(self, y):
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|         self._vhline("v", y)
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| 
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|     def _line(self, c, x, y):
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|         self._add("%s%s,%s" % (c, _ntos(x), _ntos(y)))
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| 
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|     def L(self, x, y):
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|         self._line("L", x, y)
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| 
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|     def l(self, x, y):
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|         self._line("l", x, y)
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| 
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|     def _parse_line(self, line):
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|         x1 = float(line.attrib.get("x1", 0))
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|         y1 = float(line.attrib.get("y1", 0))
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|         x2 = float(line.attrib.get("x2", 0))
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|         y2 = float(line.attrib.get("y2", 0))
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| 
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|         self._start_path()
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|         self.M(x1, y1)
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|         self.L(x2, y2)
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| 
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|     def _parse_rect(self, rect):
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|         x = float(rect.attrib.get("x", 0))
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|         y = float(rect.attrib.get("y", 0))
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|         w = float(rect.attrib.get("width"))
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|         h = float(rect.attrib.get("height"))
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|         rx = float(rect.attrib.get("rx", 0))
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|         ry = float(rect.attrib.get("ry", 0))
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| 
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|         rx = _prefer_non_zero(rx, ry)
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|         ry = _prefer_non_zero(ry, rx)
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|         # TODO there are more rules for adjusting rx, ry
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| 
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|         self._start_path()
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|         self.M(x + rx, y)
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|         self.H(x + w - rx)
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|         if rx > 0:
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|             self.A(rx, ry, x + w, y + ry)
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|         self.V(y + h - ry)
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|         if rx > 0:
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|             self.A(rx, ry, x + w - rx, y + h)
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|         self.H(x + rx)
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|         if rx > 0:
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|             self.A(rx, ry, x, y + h - ry)
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|         self.V(y + ry)
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|         if rx > 0:
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|             self.A(rx, ry, x + rx, y)
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|         self._end_path()
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| 
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|     def _parse_path(self, path):
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|         if "d" in path.attrib:
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|             self._start_path(initial_path=path.attrib["d"])
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| 
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|     def _parse_polygon(self, poly):
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|         if "points" in poly.attrib:
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|             self._start_path("M" + poly.attrib["points"])
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|             self._end_path()
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| 
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|     def _parse_polyline(self, poly):
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|         if "points" in poly.attrib:
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|             self._start_path("M" + poly.attrib["points"])
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| 
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|     def _parse_circle(self, circle):
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|         cx = float(circle.attrib.get("cx", 0))
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|         cy = float(circle.attrib.get("cy", 0))
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|         r = float(circle.attrib.get("r"))
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| 
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|         # arc doesn't seem to like being a complete shape, draw two halves
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|         self._start_path()
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|         self.M(cx - r, cy)
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|         self.A(r, r, cx + r, cy, large_arc=1)
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|         self.A(r, r, cx - r, cy, large_arc=1)
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| 
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|     def _parse_ellipse(self, ellipse):
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|         cx = float(ellipse.attrib.get("cx", 0))
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|         cy = float(ellipse.attrib.get("cy", 0))
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|         rx = float(ellipse.attrib.get("rx"))
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|         ry = float(ellipse.attrib.get("ry"))
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| 
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|         # arc doesn't seem to like being a complete shape, draw two halves
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|         self._start_path()
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|         self.M(cx - rx, cy)
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|         self.A(rx, ry, cx + rx, cy, large_arc=1)
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|         self.A(rx, ry, cx - rx, cy, large_arc=1)
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| 
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|     def add_path_from_element(self, el):
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|         tag = _strip_xml_ns(el.tag)
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|         parse_fn = getattr(self, "_parse_%s" % tag.lower(), None)
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|         if not callable(parse_fn):
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|             return False
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|         parse_fn(el)
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|         if "transform" in el.attrib:
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|             self.transforms[-1] = _transform(el.attrib["transform"])
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|         return True
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