svgpathtoolss/svgpathtools/svg_to_paths.py

283 lines
11 KiB
Python

"""This submodule contains tools for creating path objects from SVG files.
The main tool being the svg2paths() function."""
# External dependencies
from __future__ import division, absolute_import, print_function
from xml.dom.minidom import parse
import os
from io import StringIO
import re
from sys import version_info
try:
from os import PathLike as FilePathLike
except ImportError:
FilePathLike = str
# Internal dependencies
from .parser import parse_path
# f-strings are available in Python 3.6+
F_STRINGS_AVAILABLE = version_info >= (3, 6)
COORD_PAIR_TMPLT = re.compile(
r'([\+-]?\d*[\.\d]\d*[eE][\+-]?\d+|[\+-]?\d*[\.\d]\d*)' +
r'(?:\s*,\s*|\s+|(?=-))' +
r'([\+-]?\d*[\.\d]\d*[eE][\+-]?\d+|[\+-]?\d*[\.\d]\d*)'
)
def path2pathd(path):
return path.get('d')
def ellipse2pathd(ellipse):
"""converts the parameters from an ellipse or a circle to a string for a
Path object d-attribute"""
cx = ellipse.get('cx', 0)
cy = ellipse.get('cy', 0)
rx = ellipse.get('rx', None)
ry = ellipse.get('ry', None)
r = ellipse.get('r', None)
if r is not None:
rx = ry = float(r)
else:
rx = float(rx)
ry = float(ry)
cx = float(cx)
cy = float(cy)
d = ''
d += 'M' + str(cx - rx) + ',' + str(cy)
d += 'a' + str(rx) + ',' + str(ry) + ' 0 1,0 ' + str(2 * rx) + ',0'
d += 'a' + str(rx) + ',' + str(ry) + ' 0 1,0 ' + str(-2 * rx) + ',0'
return d
def polyline2pathd(polyline, is_polygon=False):
"""converts the string from a polyline points-attribute to a string for a
Path object d-attribute"""
if isinstance(polyline, str):
points = polyline
else:
points = COORD_PAIR_TMPLT.findall(polyline.get('points', ''))
closed = (float(points[0][0]) == float(points[-1][0]) and
float(points[0][1]) == float(points[-1][1]))
# The `parse_path` call ignores redundant 'z' (closure) commands
# e.g. `parse_path('M0 0L100 100Z') == parse_path('M0 0L100 100L0 0Z')`
# This check ensures that an n-point polygon is converted to an n-Line path.
if is_polygon and closed:
points.append(points[0])
d = 'M' + 'L'.join('{0} {1}'.format(x, y) for x, y in points)
if is_polygon or closed:
d += 'z'
return d
def polygon2pathd(polyline):
"""converts the string from a polygon points-attribute to a string
for a Path object d-attribute.
Note: For a polygon made from n points, the resulting path will be
composed of n lines (even if some of these lines have length zero).
"""
return polyline2pathd(polyline, True)
def rect2pathd(rect):
"""Converts an SVG-rect element to a Path d-string.
The rectangle will start at the (x,y) coordinate specified by the
rectangle object and proceed counter-clockwise."""
x, y = float(rect.get('x', 0)), float(rect.get('y', 0))
w, h = float(rect.get('width', 0)), float(rect.get('height', 0))
if 'rx' in rect or 'ry' in rect:
# if only one, rx or ry, is present, use that value for both
# https://developer.mozilla.org/en-US/docs/Web/SVG/Element/rect
rx = rect.get('rx', None)
ry = rect.get('ry', None)
if rx is None:
rx = ry or 0.
if ry is None:
ry = rx or 0.
rx, ry = float(rx), float(ry)
d = "M {} {} ".format(x + rx, y) # right of p0
d += "L {} {} ".format(x + w - rx, y) # go to p1
d += "A {} {} 0 0 1 {} {} ".format(rx, ry, x+w, y+ry) # arc for p1
d += "L {} {} ".format(x+w, y+h-ry) # above p2
d += "A {} {} 0 0 1 {} {} ".format(rx, ry, x+w-rx, y+h) # arc for p2
d += "L {} {} ".format(x+rx, y+h) # right of p3
d += "A {} {} 0 0 1 {} {} ".format(rx, ry, x, y+h-ry) # arc for p3
d += "L {} {} ".format(x, y+ry) # below p0
d += "A {} {} 0 0 1 {} {} z".format(rx, ry, x+rx, y) # arc for p0
return d
x0, y0 = x, y
x1, y1 = x + w, y
x2, y2 = x + w, y + h
x3, y3 = x, y + h
d = ("M{} {} L {} {} L {} {} L {} {} z"
"".format(x0, y0, x1, y1, x2, y2, x3, y3))
return d
if F_STRINGS_AVAILABLE:
def line2pathd(node_dict):
return f"M{node_dict['x1']} {node_dict['y1']}L{node_dict['x2']} {node_dict['y2']}"
else:
def line2pathd(node_dict):
return "M{} {}L{} {}".format(node_dict['x1'], node_dict['y1'], node_dict['x2'], node_dict['y2'])
parser_dict = {
'path': path2pathd,
'circle': ellipse2pathd,
'ellipse': ellipse2pathd,
'line': line2pathd,
'polyline': polyline2pathd,
'polygon': polygon2pathd,
'rect': rect2pathd,
}
def svg2paths(svg_file_location,
return_svg_attributes=False,
convert_circles_to_paths=True,
convert_ellipses_to_paths=True,
convert_lines_to_paths=True,
convert_polylines_to_paths=True,
convert_polygons_to_paths=True,
convert_rectangles_to_paths=True):
"""Converts an SVG into a list of Path objects and attribute dictionaries.
Converts an SVG file into a list of Path objects and a list of
dictionaries containing their attributes. This currently supports
SVG Path, Line, Polyline, Polygon, Circle, and Ellipse elements.
Args:
svg_file_location (string or file-like object): the location of the
svg file on disk or a file-like object containing the content of a
svg file
return_svg_attributes (bool): Set to True and a dictionary of
svg-attributes will be extracted and returned. See also the
`svg2paths2()` function.
convert_circles_to_paths: Set to False to exclude SVG-Circle
elements (converted to Paths). By default circles are included as
paths of two `Arc` objects.
convert_ellipses_to_paths (bool): Set to False to exclude SVG-Ellipse
elements (converted to Paths). By default ellipses are included as
paths of two `Arc` objects.
convert_lines_to_paths (bool): Set to False to exclude SVG-Line elements
(converted to Paths)
convert_polylines_to_paths (bool): Set to False to exclude SVG-Polyline
elements (converted to Paths)
convert_polygons_to_paths (bool): Set to False to exclude SVG-Polygon
elements (converted to Paths)
convert_rectangles_to_paths (bool): Set to False to exclude SVG-Rect
elements (converted to Paths).
Returns:
list: The list of Path objects.
list: The list of corresponding path attribute dictionaries.
dict (optional): A dictionary of svg-attributes (see `svg2paths2()`).
"""
# strings are interpreted as file location everything else is treated as
# file-like object and passed to the xml parser directly
from_filepath = isinstance(svg_file_location, str) or isinstance(svg_file_location, FilePathLike)
svg_file_location = os.path.abspath(svg_file_location) if from_filepath else svg_file_location
doc = parse(svg_file_location)
# todo: is this equivalent to `dict(element.attributes())`?
def dom2dict(element):
"""Converts DOM elements to dictionaries of attributes."""
keys = list(element.attributes.keys())
values = [val.value for val in list(element.attributes.values())]
d = dict(list(zip(keys, values)))
# if not dict((k, v) for k, v in element.attributes.items()) == d:
# from IPython import embed; embed() ### DEBUG
return d
include_dict = {
'circle': convert_circles_to_paths,
'ellipse': convert_ellipses_to_paths,
'line': convert_lines_to_paths,
'polyline': convert_polylines_to_paths,
'polygon': convert_polygons_to_paths,
'rect': convert_rectangles_to_paths,
}
included_elements = set(name for name, is_included in include_dict.items() if is_included)
type_attribute_dictionary_pairs = [
(node.localName, dom2dict(node)) for node in doc.documentElement.childNodes
if node.localName in included_elements
]
d_strings = [parser_dict[element_type](nd)
for element_type, nd in type_attribute_dictionary_pairs]
attribute_dictionaries = [ad for _, ad in type_attribute_dictionary_pairs]
if return_svg_attributes:
svg_attributes = dom2dict(doc.getElementsByTagName("svg")[0])
doc.unlink()
path_list = [parse_path(d) for d in d_strings]
return path_list, attribute_dictionaries, svg_attributes
else:
doc.unlink()
path_list = [parse_path(d) for d in d_strings]
return path_list, attribute_dictionaries
def svg2paths2(svg_file_location,
return_svg_attributes=True,
convert_circles_to_paths=True,
convert_ellipses_to_paths=True,
convert_lines_to_paths=True,
convert_polylines_to_paths=True,
convert_polygons_to_paths=True,
convert_rectangles_to_paths=True):
"""Convenience function; identical to svg2paths() except that
return_svg_attributes=True by default. See svg2paths() docstring for more
info."""
return svg2paths(svg_file_location=svg_file_location,
return_svg_attributes=return_svg_attributes,
convert_circles_to_paths=convert_circles_to_paths,
convert_ellipses_to_paths=convert_ellipses_to_paths,
convert_lines_to_paths=convert_lines_to_paths,
convert_polylines_to_paths=convert_polylines_to_paths,
convert_polygons_to_paths=convert_polygons_to_paths,
convert_rectangles_to_paths=convert_rectangles_to_paths)
def svgstr2paths(svg_string,
return_svg_attributes=False,
convert_circles_to_paths=True,
convert_ellipses_to_paths=True,
convert_lines_to_paths=True,
convert_polylines_to_paths=True,
convert_polygons_to_paths=True,
convert_rectangles_to_paths=True):
"""Convenience function; identical to svg2paths() except that it takes the
svg object as string. See svg2paths() docstring for more
info."""
# wrap string into StringIO object
svg_file_obj = StringIO(svg_string)
return svg2paths(svg_file_location=svg_file_obj,
return_svg_attributes=return_svg_attributes,
convert_circles_to_paths=convert_circles_to_paths,
convert_ellipses_to_paths=convert_ellipses_to_paths,
convert_lines_to_paths=convert_lines_to_paths,
convert_polylines_to_paths=convert_polylines_to_paths,
convert_polygons_to_paths=convert_polygons_to_paths,
convert_rectangles_to_paths=convert_rectangles_to_paths)