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