from collections import OrderedDict
import functools
import logging
import urllib.parse
import numpy as np
from matplotlib import _text_layout, dviread, font_manager, rcParams
from matplotlib.font_manager import FontProperties, get_font
from matplotlib.ft2font import LOAD_NO_HINTING, LOAD_TARGET_LIGHT
from matplotlib.mathtext import MathTextParser
from matplotlib.path import Path
from matplotlib.transforms import Affine2D
_log = logging.getLogger(__name__)
[docs]class TextToPath:
"""A class that converts strings to paths."""
FONT_SCALE = 100.
DPI = 72
def __init__(self):
self.mathtext_parser = MathTextParser('path')
self._texmanager = None
def _get_font(self, prop):
"""
Find the `FT2Font` matching font properties *prop*, with its size set.
"""
fname = font_manager.findfont(prop)
font = get_font(fname)
font.set_size(self.FONT_SCALE, self.DPI)
return font
def _get_hinting_flag(self):
return LOAD_NO_HINTING
def _get_char_id(self, font, ccode):
"""
Return a unique id for the given font and character-code set.
"""
return urllib.parse.quote('{}-{}'.format(font.postscript_name, ccode))
def _get_char_id_ps(self, font, ccode):
"""
Return a unique id for the given font and character-code set (for tex).
"""
ps_name = font.get_ps_font_info()[2]
char_id = urllib.parse.quote('%s-%d' % (ps_name, ccode))
return char_id
[docs] def get_text_width_height_descent(self, s, prop, ismath):
if ismath == "TeX":
texmanager = self.get_texmanager()
fontsize = prop.get_size_in_points()
w, h, d = texmanager.get_text_width_height_descent(s, fontsize,
renderer=None)
return w, h, d
fontsize = prop.get_size_in_points()
scale = fontsize / self.FONT_SCALE
if ismath:
prop = prop.copy()
prop.set_size(self.FONT_SCALE)
width, height, descent, trash, used_characters = \
self.mathtext_parser.parse(s, 72, prop)
return width * scale, height * scale, descent * scale
font = self._get_font(prop)
font.set_text(s, 0.0, flags=LOAD_NO_HINTING)
w, h = font.get_width_height()
w /= 64.0 # convert from subpixels
h /= 64.0
d = font.get_descent()
d /= 64.0
return w * scale, h * scale, d * scale
[docs] def get_text_path(self, prop, s, ismath=False):
"""
Convert text *s* to path (a tuple of vertices and codes for
matplotlib.path.Path).
Parameters
----------
prop : `~matplotlib.font_manager.FontProperties`
The font properties for the text.
s : str
The text to be converted.
ismath : {False, True, "TeX"}
If True, use mathtext parser. If "TeX", use tex for rendering.
Returns
-------
verts : list
A list of numpy arrays containing the x and y coordinates of the
vertices.
codes : list
A list of path codes.
Examples
--------
Create a list of vertices and codes from a text, and create a `.Path`
from those::
from matplotlib.path import Path
from matplotlib.textpath import TextToPath
from matplotlib.font_manager import FontProperties
fp = FontProperties(family="Humor Sans", style="italic")
verts, codes = TextToPath().get_text_path(fp, "ABC")
path = Path(verts, codes, closed=False)
Also see `TextPath` for a more direct way to create a path from a text.
"""
if ismath == "TeX":
glyph_info, glyph_map, rects = self.get_glyphs_tex(prop, s)
elif not ismath:
font = self._get_font(prop)
glyph_info, glyph_map, rects = self.get_glyphs_with_font(font, s)
else:
glyph_info, glyph_map, rects = self.get_glyphs_mathtext(prop, s)
verts, codes = [], []
for glyph_id, xposition, yposition, scale in glyph_info:
verts1, codes1 = glyph_map[glyph_id]
if len(verts1):
verts1 = np.array(verts1) * scale + [xposition, yposition]
verts.extend(verts1)
codes.extend(codes1)
for verts1, codes1 in rects:
verts.extend(verts1)
codes.extend(codes1)
return verts, codes
[docs] def get_glyphs_with_font(self, font, s, glyph_map=None,
return_new_glyphs_only=False):
"""
Convert string *s* to vertices and codes using the provided ttf font.
"""
if glyph_map is None:
glyph_map = OrderedDict()
if return_new_glyphs_only:
glyph_map_new = OrderedDict()
else:
glyph_map_new = glyph_map
xpositions = []
glyph_ids = []
for char, (_, x) in zip(s, _text_layout.layout(s, font)):
char_id = self._get_char_id(font, ord(char))
glyph_ids.append(char_id)
xpositions.append(x)
if char_id not in glyph_map:
glyph_map_new[char_id] = font.get_path()
ypositions = [0] * len(xpositions)
sizes = [1.] * len(xpositions)
rects = []
return (list(zip(glyph_ids, xpositions, ypositions, sizes)),
glyph_map_new, rects)
[docs] def get_glyphs_mathtext(self, prop, s, glyph_map=None,
return_new_glyphs_only=False):
"""
Parse mathtext string *s* and convert it to a (vertices, codes) pair.
"""
prop = prop.copy()
prop.set_size(self.FONT_SCALE)
width, height, descent, glyphs, rects = self.mathtext_parser.parse(
s, self.DPI, prop)
if not glyph_map:
glyph_map = OrderedDict()
if return_new_glyphs_only:
glyph_map_new = OrderedDict()
else:
glyph_map_new = glyph_map
xpositions = []
ypositions = []
glyph_ids = []
sizes = []
for font, fontsize, ccode, ox, oy in glyphs:
char_id = self._get_char_id(font, ccode)
if char_id not in glyph_map:
font.clear()
font.set_size(self.FONT_SCALE, self.DPI)
font.load_char(ccode, flags=LOAD_NO_HINTING)
glyph_map_new[char_id] = font.get_path()
xpositions.append(ox)
ypositions.append(oy)
glyph_ids.append(char_id)
size = fontsize / self.FONT_SCALE
sizes.append(size)
myrects = []
for ox, oy, w, h in rects:
vert1 = [(ox, oy), (ox, oy + h), (ox + w, oy + h),
(ox + w, oy), (ox, oy), (0, 0)]
code1 = [Path.MOVETO,
Path.LINETO, Path.LINETO, Path.LINETO, Path.LINETO,
Path.CLOSEPOLY]
myrects.append((vert1, code1))
return (list(zip(glyph_ids, xpositions, ypositions, sizes)),
glyph_map_new, myrects)
[docs] def get_texmanager(self):
"""Return the cached `~.texmanager.TexManager` instance."""
if self._texmanager is None:
from matplotlib.texmanager import TexManager
self._texmanager = TexManager()
return self._texmanager
[docs] def get_glyphs_tex(self, prop, s, glyph_map=None,
return_new_glyphs_only=False):
"""Convert the string *s* to vertices and codes using usetex mode."""
# Mostly borrowed from pdf backend.
dvifile = self.get_texmanager().make_dvi(s, self.FONT_SCALE)
with dviread.Dvi(dvifile, self.DPI) as dvi:
page, = dvi
if glyph_map is None:
glyph_map = OrderedDict()
if return_new_glyphs_only:
glyph_map_new = OrderedDict()
else:
glyph_map_new = glyph_map
glyph_ids, xpositions, ypositions, sizes = [], [], [], []
# Gather font information and do some setup for combining
# characters into strings.
for x1, y1, dvifont, glyph, width in page.text:
font, enc = self._get_ps_font_and_encoding(dvifont.texname)
char_id = self._get_char_id_ps(font, glyph)
if char_id not in glyph_map:
font.clear()
font.set_size(self.FONT_SCALE, self.DPI)
# See comments in _get_ps_font_and_encoding.
if enc is not None:
index = font.get_name_index(enc[glyph])
font.load_glyph(index, flags=LOAD_TARGET_LIGHT)
else:
font.load_char(glyph, flags=LOAD_TARGET_LIGHT)
glyph_map_new[char_id] = font.get_path()
glyph_ids.append(char_id)
xpositions.append(x1)
ypositions.append(y1)
sizes.append(dvifont.size / self.FONT_SCALE)
myrects = []
for ox, oy, h, w in page.boxes:
vert1 = [(ox, oy), (ox + w, oy), (ox + w, oy + h),
(ox, oy + h), (ox, oy), (0, 0)]
code1 = [Path.MOVETO,
Path.LINETO, Path.LINETO, Path.LINETO, Path.LINETO,
Path.CLOSEPOLY]
myrects.append((vert1, code1))
return (list(zip(glyph_ids, xpositions, ypositions, sizes)),
glyph_map_new, myrects)
@staticmethod
@functools.lru_cache(50)
def _get_ps_font_and_encoding(texname):
tex_font_map = dviread.PsfontsMap(dviread.find_tex_file('pdftex.map'))
psfont = tex_font_map[texname]
if psfont.filename is None:
raise ValueError(
f"No usable font file found for {psfont.psname} ({texname}). "
f"The font may lack a Type-1 version.")
font = get_font(psfont.filename)
if psfont.encoding:
# If psfonts.map specifies an encoding, use it: it gives us a
# mapping of glyph indices to Adobe glyph names; use it to convert
# dvi indices to glyph names and use the FreeType-synthesized
# unicode charmap to convert glyph names to glyph indices (with
# FT_Get_Name_Index/get_name_index), and load the glyph using
# FT_Load_Glyph/load_glyph. (That charmap has a coverage at least
# as good as, and possibly better than, the native charmaps.)
enc = dviread._parse_enc(psfont.encoding)
else:
# If psfonts.map specifies no encoding, the indices directly
# map to the font's "native" charmap; so don't use the
# FreeType-synthesized charmap but the native ones (we can't
# directly identify it but it's typically an Adobe charmap), and
# directly load the dvi glyph indices using FT_Load_Char/load_char.
for charmap_code in [
1094992451, # ADOBE_CUSTOM.
1094995778, # ADOBE_STANDARD.
]:
try:
font.select_charmap(charmap_code)
except (ValueError, RuntimeError):
pass
else:
break
else:
_log.warning("No supported encoding in font (%s).",
psfont.filename)
enc = None
return font, enc
text_to_path = TextToPath()
[docs]class TextPath(Path):
"""
Create a path from the text.
"""
def __init__(self, xy, s, size=None, prop=None,
_interpolation_steps=1, usetex=False):
r"""
Create a path from the text. Note that it simply is a path,
not an artist. You need to use the `~.PathPatch` (or other artists)
to draw this path onto the canvas.
Parameters
----------
xy : tuple or array of two float values
Position of the text. For no offset, use ``xy=(0, 0)``.
s : str
The text to convert to a path.
size : float, optional
Font size in points. Defaults to the size specified via the font
properties *prop*.
prop : `matplotlib.font_manager.FontProperties`, optional
Font property. If not provided, will use a default
``FontProperties`` with parameters from the
:ref:`rcParams <matplotlib-rcparams>`.
_interpolation_steps : int, optional
(Currently ignored)
usetex : bool, default: False
Whether to use tex rendering.
Examples
--------
The following creates a path from the string "ABC" with Helvetica
font face; and another path from the latex fraction 1/2::
from matplotlib.textpath import TextPath
from matplotlib.font_manager import FontProperties
fp = FontProperties(family="Helvetica", style="italic")
path1 = TextPath((12, 12), "ABC", size=12, prop=fp)
path2 = TextPath((0, 0), r"$\frac{1}{2}$", size=12, usetex=True)
Also see :doc:`/gallery/text_labels_and_annotations/demo_text_path`.
"""
# Circular import.
from matplotlib.text import Text
prop = FontProperties._from_any(prop)
if size is None:
size = prop.get_size_in_points()
self._xy = xy
self.set_size(size)
self._cached_vertices = None
s, ismath = Text(usetex=usetex)._preprocess_math(s)
self._vertices, self._codes = text_to_path.get_text_path(
prop, s, ismath=ismath)
self._should_simplify = False
self._simplify_threshold = rcParams['path.simplify_threshold']
self._interpolation_steps = _interpolation_steps
[docs] def set_size(self, size):
"""Set the text size."""
self._size = size
self._invalid = True
[docs] def get_size(self):
"""Get the text size."""
return self._size
@property
def vertices(self):
"""
Return the cached path after updating it if necessary.
"""
self._revalidate_path()
return self._cached_vertices
@property
def codes(self):
"""
Return the codes
"""
return self._codes
def _revalidate_path(self):
"""
Update the path if necessary.
The path for the text is initially create with the font size of
`~.FONT_SCALE`, and this path is rescaled to other size when necessary.
"""
if self._invalid or self._cached_vertices is None:
tr = (Affine2D()
.scale(self._size / text_to_path.FONT_SCALE)
.translate(*self._xy))
self._cached_vertices = tr.transform(self._vertices)
self._invalid = False
