Invalid Arc parsing for Flags. #53
Comments
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Yeah, I saw that when originally implementing this and filed it under "that makes no sense, look at it later" and then forgot about it... |
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I've only seen such a thing in this test and had to check the spec to see if it could plausibly be correct. And would require some pretty radical changes to fix, and it's one special weird quirk with arc grammar. |
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Fixing this in PATTERN_WS = r'[\s\t\n]*'
PATTERN_COMMA = r'(?:\s*,\s*|\s+|(?=-))'
PATTERN_COMMAWSP = r'[ ,\t\n\x09\x0A\x0C\x0D]+'
PATTERN_FLOAT = '[-+]?[0-9]*\.?[0-9]+(?:[eE][-+]?[0-9]+)?'
svg_parse = [
('COMMAND', r'[MmZzLlHhVvCcSsQqTtAa]'),
('SKIP', PATTERN_COMMAWSP)
]
svg_re = re.compile('|'.join('(?P<%s>%s)' % pair for pair in svg_parse))
num_parse = [
('FLOAT', PATTERN_FLOAT),
('CLOSE', r'[Zz]'),
('SKIP', PATTERN_COMMAWSP)
]
num_re = re.compile('|'.join('(?P<%s>%s)' % pair for pair in num_parse))
flag_parse = [
('FLAG', r'[01]'),
('SKIP', PATTERN_COMMAWSP)
]
flag_re = re.compile('|'.join('(?P<%s>%s)' % pair for pair in flag_parse))
class SVGLexicalParser:
def __init__(self):
self.parser = None
self.pathd = None
self.pos = 0
self.limit = 0
self.inline_close = None
def _command(self):
while self.pos < self.limit:
match = svg_re.match(self.pathd, self.pos)
if match is None:
return None # Did not match at command sequence.
self.pos = match.end()
kind = match.lastgroup
if kind == 'SKIP':
continue
return match.group()
return None
def _more(self):
while self.pos < self.limit:
match = num_re.match(self.pathd, self.pos)
if match is None:
return False
kind = match.lastgroup
if kind == 'CLOSE':
self.inline_close = match.group()
return False
if kind == 'SKIP':
# move skipped elements forward.
self.pos = match.end()
continue
return True
return None
def _number(self):
while self.pos < self.limit:
match = num_re.match(self.pathd, self.pos)
if match is None:
break # No more matches.
kind = match.lastgroup
if kind == 'CLOSE':
# Inline Close
self.inline_close = match.group()
return None
self.pos = match.end()
if kind == 'SKIP':
continue
return float(match.group())
return None
def _flag(self):
while self.pos < self.limit:
match = flag_re.match(self.pathd, self.pos)
if match is None:
break # No more matches.
self.pos = match.end()
kind = match.lastgroup
if kind == 'SKIP':
continue
return bool(int(match.group()))
return None
def _coord(self):
x = self._number()
if x is None:
return None
y = self._number()
if y is None:
raise ValueError
return x, y
def _rcoord(self):
position = self._coord()
if position is None:
return None
current_pos = self.parser.current_point
if current_pos is None:
return position
return position[0] + current_pos[0], position[1] + current_pos[1]
def parse(self, parser, pathd):
self.parser = parser
self.parser.start()
self.pathd = pathd
self.pos = 0
self.limit = len(pathd)
while True:
cmd = self._command()
if cmd is None:
return
elif cmd == 'z' or cmd == 'Z':
if self._more():
raise ValueError
self.parser.closed(relative=cmd.islower())
self.inline_close = None
continue
elif cmd == 'm':
if not self._more():
raise ValueError
coord = self._rcoord()
self.parser.move(coord, relative=True)
while self._more():
coord = self._rcoord()
self.parser.line(coord, relative=True)
elif cmd == 'M':
if not self._more():
raise ValueError
coord = self._coord()
self.parser.move(coord, relative=False)
while self._more():
coord = self._coord()
self.parser.line(coord, relative=False)
elif cmd == 'l':
while True:
coord = self._rcoord()
if coord is None:
coord = self.inline_close
if coord is None:
raise ValueError
self.parser.line(coord, relative=True)
if not self._more():
break
elif cmd == 'L':
while True:
coord = self._coord()
if coord is None:
coord = self.inline_close
if coord is None:
raise ValueError
self.parser.line(coord, relative=False)
if not self._more():
break
elif cmd == 't':
while True:
coord = self._rcoord()
if coord is None:
coord = self.inline_close
if coord is None:
raise ValueError
self.parser.smooth_quad(coord, relative=True)
if not self._more():
break
elif cmd == 'T':
while True:
coord = self._coord()
if coord is None:
coord = self.inline_close
if coord is None:
raise ValueError
self.parser.smooth_quad(coord, relative=False)
if not self._more():
break
elif cmd == 'h':
while True:
value = self._number()
self.parser.horizontal(value, relative=True)
if not self._more():
break
elif cmd == 'H':
while True:
value = self._number()
self.parser.horizontal(value, relative=False)
if not self._more():
break
elif cmd == 'v':
while True:
value = self._number()
self.parser.vertical(value, relative=True)
if not self._more():
break
elif cmd == 'V':
while self._more():
value = self._number()
self.parser.vertical(value, relative=False)
elif cmd == 'c':
while True:
coord1, coord2, coord3 = self._rcoord(), self._rcoord(), self._rcoord()
if coord1 is None:
coord1 = self.inline_close
if coord1 is None:
raise ValueError
if coord2 is None:
coord2 = self.inline_close
if coord2 is None:
raise ValueError
if coord3 is None:
coord3 = self.inline_close
if coord3 is None:
raise ValueError
self.parser.cubic(coord1, coord2, coord3, relative=True)
if not self._more():
break
elif cmd == 'C':
while True:
coord1, coord2, coord3 = self._coord(), self._coord(), self._coord()
if coord1 is None:
coord1 = self.inline_close
if coord1 is None:
raise ValueError
if coord2 is None:
coord2 = self.inline_close
if coord2 is None:
raise ValueError
if coord3 is None:
coord3 = self.inline_close
if coord3 is None:
raise ValueError
self.parser.cubic(coord1, coord2, coord3, relative=False)
if not self._more():
break
elif cmd == 'q':
while True:
coord1, coord2 = self._rcoord(), self._rcoord()
if coord1 is None:
coord1 = self.inline_close
if coord1 is None:
raise ValueError
if coord2 is None:
coord2 = self.inline_close
if coord2 is None:
raise ValueError
self.parser.quad(coord1, coord2, relative=True)
if not self._more():
break
elif cmd == 'Q':
while True:
coord1, coord2 = self._coord(), self._coord()
if coord1 is None:
coord1 = self.inline_close
if coord1 is None:
raise ValueError
if coord2 is None:
coord2 = self.inline_close
if coord2 is None:
raise ValueError
self.parser.quad(coord1, coord2, relative=False)
if not self._more():
break
elif cmd == 's':
while True:
coord1, coord2 = self._rcoord(), self._rcoord()
if coord1 is None:
coord1 = self.inline_close
if coord1 is None:
raise ValueError
if coord2 is None:
coord2 = self.inline_close
if coord2 is None:
raise ValueError
self.parser.smooth_cubic(coord1, coord2, relative=True)
if not self._more():
break
elif cmd == 'S':
while True:
coord1, coord2 = self._coord(), self._coord()
if coord1 is None:
coord1 = self.inline_close
if coord1 is None:
raise ValueError
if coord2 is None:
coord2 = self.inline_close
if coord2 is None:
raise ValueError
self.parser.smooth_cubic(coord1, coord2, relative=False)
if not self._more():
break
elif cmd == 'a':
while self._more():
rx, ry, rotation, arc, sweep, coord = \
self._number(), self._number(), self._number(), self._flag(), self._flag(), self._rcoord()
if sweep is None:
raise ValueError
if coord is None:
coord = self.inline_close
if coord is None:
raise ValueError
self.parser.arc(rx, ry, rotation, arc, sweep, coord, relative=True)
elif cmd == 'A':
while self._more():
rx, ry, rotation, arc, sweep, coord = \
self._number(), self._number(), self._number(), self._flag(), self._flag(), self._coord()
if coord is None:
coord = self.inline_close
if coord is None:
raise ValueError
self.parser.arc(rx, ry, rotation, arc, sweep, coord, relative=False)
self.parser.end() |
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It's bizarre that the GNOME developers would put one of these paths in a system file, but they did. See #69. |
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I made a new parser that fixes this issue, and released a 5.0.0a1, with this. It's an alpha, because besides this issue, I only fixed the easy bugs, and of course, it's a complete rewrite of the parser, so there may be new bugs. Also, I didn't do anything backwards incompatible, which I have a huge urge to do. |
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I realized after completed almost all the So basically perform a subset of how browsers parse things. And use the code to manipulate svg DOM-nodes like one would do for javascript. Browsers apparently have baked in solutions to a lot of problems within svg parsing ( http://taligarsiel.com/Projects/howbrowserswork1.htm ). And really you can do bootstrapping of nodes to replace the default parsed xml node with a more specific svg-type node (as browsers do) (you parse This stuff basically solves a question of how you could load an SVG file and have a node-tree object like you'd have for You can apply CSS to the DOM Tree and then re-render the tree to get a different set of rendered paths, rather than make a bunch of makeshift changes to partially rendered svg-like objects. This solves harder problems like modifying a transform on a But the entire thing is basically a rewrite that fixes things profoundly. It basically makes the broken family of good python svg projects:
It might be tempting to break backwards compatibility but it's probably better to do so in a different project. |
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Yes, SVG is an application of XML, and in general, should be treated like and parsed like XML. svg.path is entirely dedicated only to parsing the |
This may not be worth fixing.
I checked the SVG 1.1 XBNF ( https://www.w3.org/TR/SVG11/paths.html#PathDataBNF ) to be sure, and it's completely true. It turns out:
... is a valid path. Since the flag token is either 1 or 0 and does not require any space to say it's valid. This is a test in the W3C_SVG_11_TestSuite. Namely
paths-data-20-f.svg.Flags are only used in the BNF for arcs:
Since the comma-wsp? has
?it's optional so 1125 means 1 1 25.The text was updated successfully, but these errors were encountered: