Move Path Parsing into Path. (#114)

pull/115/head
tatarize 2020-07-06 09:01:15 -09:00 committed by GitHub
parent c89c68f421
commit 90dfeb7b13
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 234 additions and 193 deletions

View File

@ -4,205 +4,15 @@ Note: This file was taken (nearly) as is from the svg.path module (v 2.0)."""
# External dependencies
from __future__ import division, absolute_import, print_function
import re
import numpy as np
import warnings
# Internal dependencies
from .path import Path, Line, QuadraticBezier, CubicBezier, Arc
# To maintain forward/backward compatibility
try:
str = basestring
except NameError:
pass
COMMANDS = set('MmZzLlHhVvCcSsQqTtAa')
UPPERCASE = set('MZLHVCSQTA')
COMMAND_RE = re.compile("([MmZzLlHhVvCcSsQqTtAa])")
FLOAT_RE = re.compile("[-+]?[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
from .path import Path
def parse_path(pathdef, current_pos=0j, tree_element=None):
# 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.
elements = list(_tokenize_path(pathdef))
# Reverse for easy use of .pop()
elements.reverse()
if tree_element is None:
segments = Path()
else:
segments = Path(tree_element=tree_element)
start_pos = None
command = None
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)))
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
# 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 not (current_pos == start_pos):
segments.append(Line(current_pos, start_pos))
segments.closed = True
current_pos = start_pos
command = None
elif command == 'L':
x = elements.pop()
y = elements.pop()
pos = float(x) + float(y) * 1j
if not absolute:
pos += current_pos
segments.append(Line(current_pos, pos))
current_pos = pos
elif command == 'H':
x = elements.pop()
pos = float(x) + current_pos.imag * 1j
if not absolute:
pos += current_pos.real
segments.append(Line(current_pos, pos))
current_pos = pos
elif command == 'V':
y = elements.pop()
pos = current_pos.real + float(y) * 1j
if not absolute:
pos += current_pos.imag * 1j
segments.append(Line(current_pos, pos))
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
segments.append(CubicBezier(current_pos, control1, control2, end))
current_pos = end
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 - segments[-1].control2
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
segments.append(CubicBezier(current_pos, control1, control2, end))
current_pos = end
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
segments.append(QuadraticBezier(current_pos, control, end))
current_pos = end
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 - segments[-1].control
end = float(elements.pop()) + float(elements.pop()) * 1j
if not absolute:
end += current_pos
segments.append(QuadraticBezier(current_pos, control, end))
current_pos = end
elif command == 'A':
radius = float(elements.pop()) + float(elements.pop()) * 1j
rotation = float(elements.pop())
arc = float(elements.pop())
sweep = float(elements.pop())
end = float(elements.pop()) + float(elements.pop()) * 1j
if not absolute:
end += current_pos
segments.append(Arc(current_pos, radius, rotation, arc, sweep, end))
current_pos = end
return segments
return Path(pathdef, current_pos=current_pos, tree_element=tree_element)
def _check_num_parsed_values(values, allowed):

View File

@ -6,6 +6,7 @@ Arc."""
from __future__ import division, absolute_import, print_function
from math import sqrt, cos, sin, acos, asin, degrees, radians, log, pi, ceil
from cmath import exp, sqrt as csqrt, phase
import re
try:
from collections.abc import MutableSequence # noqa
except ImportError:
@ -26,6 +27,17 @@ from .bezier import (bezier_intersections, bezier_bounding_box, split_bezier,
from .misctools import BugException
from .polytools import rational_limit, polyroots, polyroots01, imag, real
# To maintain forward/backward compatibility
try:
str = basestring
except NameError:
pass
COMMANDS = set('MmZzLlHhVvCcSsQqTtAa')
UPPERCASE = set('MZLHVCSQTA')
COMMAND_RE = re.compile("([MmZzLlHhVvCcSsQqTtAa])")
FLOAT_RE = re.compile("[-+]?[0-9]*\.?[0-9]+(?:[eE][-+]?[0-9]+)?")
# Default Parameters ##########################################################
@ -2246,11 +2258,24 @@ class Path(MutableSequence):
meta = None # meant as container for storage of arbitrary meta data
def __init__(self, *segments, **kw):
self._segments = list(segments)
self._length = None
self._lengths = None
if 'closed' in kw:
self.closed = kw['closed'] # DEPRECATED
if len(segments) >= 1:
if isinstance(segments[0], str):
if len(segments) >= 2:
current_pos = segments[1]
elif 'current_pos' in kw:
current_pos = kw['current_pos']
else:
current_pos = 0j
self._segments = list()
self._parse_path(segments[0], current_pos)
else:
self._segments = list(segments)
else:
self._segments = list()
if self._segments:
self._start = self._segments[0].start
self._end = self._segments[-1].end
@ -2880,3 +2905,179 @@ class Path(MutableSequence):
opt = complex(xmin-1, ymin-1)
return path_encloses_pt(pt, opt, other)
def _tokenize_path(self, 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(self, pathdef, current_pos=0j, tree_element=None):
# 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.
elements = list(self._tokenize_path(pathdef))
# Reverse for easy use of .pop()
elements.reverse()
segments = self._segments
start_pos = None
command = None
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)))
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
# 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 not (current_pos == start_pos):
segments.append(Line(current_pos, start_pos))
self.closed = True
current_pos = start_pos
command = None
elif command == 'L':
x = elements.pop()
y = elements.pop()
pos = float(x) + float(y) * 1j
if not absolute:
pos += current_pos
segments.append(Line(current_pos, pos))
current_pos = pos
elif command == 'H':
x = elements.pop()
pos = float(x) + current_pos.imag * 1j
if not absolute:
pos += current_pos.real
segments.append(Line(current_pos, pos))
current_pos = pos
elif command == 'V':
y = elements.pop()
pos = current_pos.real + float(y) * 1j
if not absolute:
pos += current_pos.imag * 1j
segments.append(Line(current_pos, pos))
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
segments.append(CubicBezier(current_pos, control1, control2, end))
current_pos = end
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 - segments[-1].control2
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
segments.append(CubicBezier(current_pos, control1, control2, end))
current_pos = end
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
segments.append(QuadraticBezier(current_pos, control, end))
current_pos = end
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 - segments[-1].control
end = float(elements.pop()) + float(elements.pop()) * 1j
if not absolute:
end += current_pos
segments.append(QuadraticBezier(current_pos, control, end))
current_pos = end
elif command == 'A':
radius = float(elements.pop()) + float(elements.pop()) * 1j
rotation = float(elements.pop())
arc = float(elements.pop())
sweep = float(elements.pop())
end = float(elements.pop()) + float(elements.pop()) * 1j
if not absolute:
end += current_pos
segments.append(Arc(current_pos, radius, rotation, arc, sweep, end))
current_pos = end
return segments

View File

@ -247,3 +247,33 @@ class TestParser(unittest.TestCase):
skewX(40)
scale(10 0.5)""")
))
def test_pathd_init(self):
path0 = Path('')
path1 = parse_path("M 100 100 L 300 100 L 200 300 z")
path2 = Path("M 100 100 L 300 100 L 200 300 z")
self.assertEqual(path1, path2)
path1 = parse_path("m 100 100 L 300 100 L 200 300 z", current_pos=50+50j)
path2 = Path("m 100 100 L 300 100 L 200 300 z")
self.assertNotEqual(path1, path2)
path1 = parse_path("m 100 100 L 300 100 L 200 300 z")
path2 = Path("m 100 100 L 300 100 L 200 300 z", current_pos=50 + 50j)
self.assertNotEqual(path1, path2)
path1 = parse_path("m 100 100 L 300 100 L 200 300 z", current_pos=50 + 50j)
path2 = Path("m 100 100 L 300 100 L 200 300 z", current_pos=50 + 50j)
self.assertEqual(path1, path2)
path1 = parse_path("m 100 100 L 300 100 L 200 300 z", 50+50j)
path2 = Path("m 100 100 L 300 100 L 200 300 z")
self.assertNotEqual(path1, path2)
path1 = parse_path("m 100 100 L 300 100 L 200 300 z")
path2 = Path("m 100 100 L 300 100 L 200 300 z", 50 + 50j)
self.assertNotEqual(path1, path2)
path1 = parse_path("m 100 100 L 300 100 L 200 300 z", 50 + 50j)
path2 = Path("m 100 100 L 300 100 L 200 300 z", 50 + 50j)
self.assertEqual(path1, path2)