Lib/fontTools/svgLib/path/parser.py - third_party/fonttools - Git at Google

 # SVG Path specification parser.
 # This is an adaptation from 'svg.path' by Lennart Regebro (@regebro),
 # modified so that the parser takes a FontTools Pen object instead of
 # returning a list of svg.path Path objects.
 # The original code can be found at:
 # https://github.com/regebro/svg.path/blob/4f9b6e3/src/svg/path/parser.py
 # Copyright (c) 2013-2014 Lennart Regebro
 # License: MIT

 from __future__ import (
     print_function, division, absolute_import, unicode_literals)
 from fontTools.misc.py23 import *
 from .arc import EllipticalArc
 import re


 COMMANDS = set('MmZzLlHhVvCcSsQqTtAa')
 UPPERCASE = set('MZLHVCSQTA')

 COMMAND_RE = re.compile("([MmZzLlHhVvCcSsQqTtAa])")
 FLOAT_RE = re.compile(r"[-+]?[0-9]*\.?[0-9]+(?:[eE][-+]?[0-9]+)?")


 def _tokenize_path(pathdef):
     for x in COMMAND_RE.split(pathdef):
         if x in COMMANDS:
             yield x
         for token in FLOAT_RE.findall(x):
             yield token


 def parse_path(pathdef, pen, current_pos=(0, 0), arc_class=EllipticalArc):
     """ Parse SVG path definition (i.e. "d" attribute of <path> elements)
     and call a 'pen' object's moveTo, lineTo, curveTo, qCurveTo and closePath
     methods.

     If 'current_pos' (2-float tuple) is provided, the initial moveTo will
     be relative to that instead being absolute.

     If the pen has an "arcTo" method, it is called with the original values
     of the elliptical arc curve commands:

         pen.arcTo(rx, ry, rotation, arc_large, arc_sweep, (x, y))

     Otherwise, the arcs are approximated by series of cubic Bezier segments
     ("curveTo"), one every 90 degrees.
     """
     # In the SVG specs, initial movetos are absolute, even if
     # specified as 'm'. This is the default behavior here as well.
     # But if you pass in a current_pos variable, the initial moveto
     # will be relative to that current_pos. This is useful.
     current_pos = complex(*current_pos)

     elements = list(_tokenize_path(pathdef))
     # Reverse for easy use of .pop()
     elements.reverse()

     start_pos = None
     command = None
     last_control = None

     have_arcTo = hasattr(pen, "arcTo")

     while elements:

         if elements[-1] in COMMANDS:
             # New command.
             last_command = command  # Used by S and T
             command = elements.pop()
             absolute = command in UPPERCASE
             command = command.upper()
         else:
             # If this element starts with numbers, it is an implicit command
             # and we don't change the command. Check that it's allowed:
             if command is None:
                 raise ValueError("Unallowed implicit command in %s, position %s" % (
                     pathdef, len(pathdef.split()) - len(elements)))
             last_command = command  # Used by S and T

         if command == 'M':
             # Moveto command.
             x = elements.pop()
             y = elements.pop()
             pos = float(x) + float(y) * 1j
             if absolute:
                 current_pos = pos
             else:
                 current_pos += pos

             # M is not preceded by Z; it's an open subpath
             if start_pos is not None:
                 pen.endPath()

             pen.moveTo((current_pos.real, current_pos.imag))

             # when M is called, reset start_pos
             # This behavior of Z is defined in svg spec:
             # http://www.w3.org/TR/SVG/paths.html#PathDataClosePathCommand
             start_pos = current_pos

             # Implicit moveto commands are treated as lineto commands.
             # So we set command to lineto here, in case there are
             # further implicit commands after this moveto.
             command = 'L'

         elif command == 'Z':
             # Close path
             if current_pos != start_pos:
                 pen.lineTo((start_pos.real, start_pos.imag))
             pen.closePath()
             current_pos = start_pos
             start_pos = None
             command = None  # You can't have implicit commands after closing.

         elif command == 'L':
             x = elements.pop()
             y = elements.pop()
             pos = float(x) + float(y) * 1j
             if not absolute:
                 pos += current_pos
             pen.lineTo((pos.real, pos.imag))
             current_pos = pos

         elif command == 'H':
             x = elements.pop()
             pos = float(x) + current_pos.imag * 1j
             if not absolute:
                 pos += current_pos.real
             pen.lineTo((pos.real, pos.imag))
             current_pos = pos

         elif command == 'V':
             y = elements.pop()
             pos = current_pos.real + float(y) * 1j
             if not absolute:
                 pos += current_pos.imag * 1j
             pen.lineTo((pos.real, pos.imag))
             current_pos = pos

         elif command == 'C':
             control1 = float(elements.pop()) + float(elements.pop()) * 1j
             control2 = float(elements.pop()) + float(elements.pop()) * 1j
             end = float(elements.pop()) + float(elements.pop()) * 1j

             if not absolute:
                 control1 += current_pos
                 control2 += current_pos
                 end += current_pos

             pen.curveTo((control1.real, control1.imag),
                         (control2.real, control2.imag),
                         (end.real, end.imag))
             current_pos = end
             last_control = control2

         elif command == 'S':
             # Smooth curve. First control point is the "reflection" of
             # the second control point in the previous path.

             if last_command not in 'CS':
                 # If there is no previous command or if the previous command
                 # was not an C, c, S or s, assume the first control point is
                 # coincident with the current point.
                 control1 = current_pos
             else:
                 # The first control point is assumed to be the reflection of
                 # the second control point on the previous command relative
                 # to the current point.
                 control1 = current_pos + current_pos - last_control

             control2 = float(elements.pop()) + float(elements.pop()) * 1j
             end = float(elements.pop()) + float(elements.pop()) * 1j

             if not absolute:
                 control2 += current_pos
                 end += current_pos

             pen.curveTo((control1.real, control1.imag),
                         (control2.real, control2.imag),
                         (end.real, end.imag))
             current_pos = end
             last_control = control2

         elif command == 'Q':
             control = float(elements.pop()) + float(elements.pop()) * 1j
             end = float(elements.pop()) + float(elements.pop()) * 1j

             if not absolute:
                 control += current_pos
                 end += current_pos

             pen.qCurveTo((control.real, control.imag), (end.real, end.imag))
             current_pos = end
             last_control = control

         elif command == 'T':
             # Smooth curve. Control point is the "reflection" of
             # the second control point in the previous path.

             if last_command not in 'QT':
                 # If there is no previous command or if the previous command
                 # was not an Q, q, T or t, assume the first control point is
                 # coincident with the current point.
                 control = current_pos
             else:
                 # The control point is assumed to be the reflection of
                 # the control point on the previous command relative
                 # to the current point.
                 control = current_pos + current_pos - last_control

             end = float(elements.pop()) + float(elements.pop()) * 1j

             if not absolute:
                 end += current_pos

             pen.qCurveTo((control.real, control.imag), (end.real, end.imag))
             current_pos = end
             last_control = control

         elif command == 'A':
             rx = float(elements.pop())
             ry = float(elements.pop())
             rotation = float(elements.pop())
             arc_large = bool(int(elements.pop()))
             arc_sweep = bool(int(elements.pop()))
             end = float(elements.pop()) + float(elements.pop()) * 1j

             if not absolute:
                 end += current_pos

             # if the pen supports arcs, pass the values unchanged, otherwise
             # approximate the arc with a series of cubic bezier curves
             if have_arcTo:
                 pen.arcTo(
                     rx,
                     ry,
                     rotation,
                     arc_large,
                     arc_sweep,
                     (end.real, end.imag),
                 )
             else:
                 arc = arc_class(
                     current_pos, rx, ry, rotation, arc_large, arc_sweep, end
                 )
                 arc.draw(pen)

             current_pos = end

     # no final Z command, it's an open path
     if start_pos is not None:
         pen.endPath()
	# SVG Path specification parser.
	# This is an adaptation from 'svg.path' by Lennart Regebro (@regebro),
	# modified so that the parser takes a FontTools Pen object instead of
	# returning a list of svg.path Path objects.
	# The original code can be found at:
	# https://github.com/regebro/svg.path/blob/4f9b6e3/src/svg/path/parser.py
	# Copyright (c) 2013-2014 Lennart Regebro
	# License: MIT

	from __future__ import (
	print_function, division, absolute_import, unicode_literals)
	from fontTools.misc.py23 import *
	from .arc import EllipticalArc
	import re


	COMMANDS = set('MmZzLlHhVvCcSsQqTtAa')
	UPPERCASE = set('MZLHVCSQTA')

	COMMAND_RE = re.compile("([MmZzLlHhVvCcSsQqTtAa])")
	FLOAT_RE = re.compile(r"[-+]?[0-9]*\.?[0-9]+(?:[eE][-+]?[0-9]+)?")


	def _tokenize_path(pathdef):
	for x in COMMAND_RE.split(pathdef):
	if x in COMMANDS:
	yield x
	for token in FLOAT_RE.findall(x):
	yield token


	def parse_path(pathdef, pen, current_pos=(0, 0), arc_class=EllipticalArc):
	""" Parse SVG path definition (i.e. "d" attribute of <path> elements)
	and call a 'pen' object's moveTo, lineTo, curveTo, qCurveTo and closePath
	methods.

	If 'current_pos' (2-float tuple) is provided, the initial moveTo will
	be relative to that instead being absolute.

	If the pen has an "arcTo" method, it is called with the original values
	of the elliptical arc curve commands:

	pen.arcTo(rx, ry, rotation, arc_large, arc_sweep, (x, y))

	Otherwise, the arcs are approximated by series of cubic Bezier segments
	("curveTo"), one every 90 degrees.
	"""
	# In the SVG specs, initial movetos are absolute, even if
	# specified as 'm'. This is the default behavior here as well.
	# But if you pass in a current_pos variable, the initial moveto
	# will be relative to that current_pos. This is useful.
	current_pos = complex(*current_pos)

	elements = list(_tokenize_path(pathdef))
	# Reverse for easy use of .pop()
	elements.reverse()

	start_pos = None
	command = None
	last_control = None

	have_arcTo = hasattr(pen, "arcTo")

	while elements:

	if elements[-1] in COMMANDS:
	# New command.
	last_command = command # Used by S and T
	command = elements.pop()
	absolute = command in UPPERCASE
	command = command.upper()
	else:
	# If this element starts with numbers, it is an implicit command
	# and we don't change the command. Check that it's allowed:
	if command is None:
	raise ValueError("Unallowed implicit command in %s, position %s" % (
	pathdef, len(pathdef.split()) - len(elements)))
	last_command = command # Used by S and T

	if command == 'M':
	# Moveto command.
	x = elements.pop()
	y = elements.pop()
	pos = float(x) + float(y) * 1j
	if absolute:
	current_pos = pos
	else:
	current_pos += pos

	# M is not preceded by Z; it's an open subpath
	if start_pos is not None:
	pen.endPath()

	pen.moveTo((current_pos.real, current_pos.imag))

	# when M is called, reset start_pos
	# This behavior of Z is defined in svg spec:
	# http://www.w3.org/TR/SVG/paths.html#PathDataClosePathCommand
	start_pos = current_pos

	# Implicit moveto commands are treated as lineto commands.
	# So we set command to lineto here, in case there are
	# further implicit commands after this moveto.
	command = 'L'

	elif command == 'Z':
	# Close path
	if current_pos != start_pos:
	pen.lineTo((start_pos.real, start_pos.imag))
	pen.closePath()
	current_pos = start_pos
	start_pos = None
	command = None # You can't have implicit commands after closing.

	elif command == 'L':
	x = elements.pop()
	y = elements.pop()
	pos = float(x) + float(y) * 1j
	if not absolute:
	pos += current_pos
	pen.lineTo((pos.real, pos.imag))
	current_pos = pos

	elif command == 'H':
	x = elements.pop()
	pos = float(x) + current_pos.imag * 1j
	if not absolute:
	pos += current_pos.real
	pen.lineTo((pos.real, pos.imag))
	current_pos = pos

	elif command == 'V':
	y = elements.pop()
	pos = current_pos.real + float(y) * 1j
	if not absolute:
	pos += current_pos.imag * 1j
	pen.lineTo((pos.real, pos.imag))
	current_pos = pos

	elif command == 'C':
	control1 = float(elements.pop()) + float(elements.pop()) * 1j
	control2 = float(elements.pop()) + float(elements.pop()) * 1j
	end = float(elements.pop()) + float(elements.pop()) * 1j

	if not absolute:
	control1 += current_pos
	control2 += current_pos
	end += current_pos

	pen.curveTo((control1.real, control1.imag),
	(control2.real, control2.imag),
	(end.real, end.imag))
	current_pos = end
	last_control = control2

	elif command == 'S':
	# Smooth curve. First control point is the "reflection" of
	# the second control point in the previous path.

	if last_command not in 'CS':
	# If there is no previous command or if the previous command
	# was not an C, c, S or s, assume the first control point is
	# coincident with the current point.
	control1 = current_pos
	else:
	# The first control point is assumed to be the reflection of
	# the second control point on the previous command relative
	# to the current point.
	control1 = current_pos + current_pos - last_control

	control2 = float(elements.pop()) + float(elements.pop()) * 1j
	end = float(elements.pop()) + float(elements.pop()) * 1j

	if not absolute:
	control2 += current_pos
	end += current_pos

	pen.curveTo((control1.real, control1.imag),
	(control2.real, control2.imag),
	(end.real, end.imag))
	current_pos = end
	last_control = control2

	elif command == 'Q':
	control = float(elements.pop()) + float(elements.pop()) * 1j
	end = float(elements.pop()) + float(elements.pop()) * 1j

	if not absolute:
	control += current_pos
	end += current_pos

	pen.qCurveTo((control.real, control.imag), (end.real, end.imag))
	current_pos = end
	last_control = control

	elif command == 'T':
	# Smooth curve. Control point is the "reflection" of
	# the second control point in the previous path.

	if last_command not in 'QT':
	# If there is no previous command or if the previous command
	# was not an Q, q, T or t, assume the first control point is
	# coincident with the current point.
	control = current_pos
	else:
	# The control point is assumed to be the reflection of
	# the control point on the previous command relative
	# to the current point.
	control = current_pos + current_pos - last_control

	end = float(elements.pop()) + float(elements.pop()) * 1j

	if not absolute:
	end += current_pos

	pen.qCurveTo((control.real, control.imag), (end.real, end.imag))
	current_pos = end
	last_control = control

	elif command == 'A':
	rx = float(elements.pop())
	ry = float(elements.pop())
	rotation = float(elements.pop())
	arc_large = bool(int(elements.pop()))
	arc_sweep = bool(int(elements.pop()))
	end = float(elements.pop()) + float(elements.pop()) * 1j

	if not absolute:
	end += current_pos

	# if the pen supports arcs, pass the values unchanged, otherwise
	# approximate the arc with a series of cubic bezier curves
	if have_arcTo:
	pen.arcTo(
	rx,
	ry,
	rotation,
	arc_large,
	arc_sweep,
	(end.real, end.imag),
	)
	else:
	arc = arc_class(
	current_pos, rx, ry, rotation, arc_large, arc_sweep, end
	)
	arc.draw(pen)

	current_pos = end

	# no final Z command, it's an open path
	if start_pos is not None:
	pen.endPath()