matplotlib/lib/matplotlib/textpath.py at v3.11.2 · matplotlib/matplotlib · GitHub

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from collections import OrderedDict

import logging

import urllib.parse

import numpy as np

from matplotlib import _text_helpers, dviread

from matplotlib.font_manager import (

FontProperties, get_font, fontManager as _fontManager

)

from matplotlib.ft2font import LoadFlags

from matplotlib.mathtext import MathTextParser

from matplotlib.path import Path

from matplotlib.texmanager import TexManager

from matplotlib.transforms import Affine2D

_log = logging.getLogger(__name__)

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.

"""

filenames = _fontManager._find_fonts_by_props(prop)

font = get_font(filenames)

font.set_size(self.FONT_SCALE, self.DPI)

return font

def _get_hinting_flag(self):

return LoadFlags.NO_HINTING

def _get_glyph_repr(self, font, glyph):

"""Return a unique id for the given font and glyph index."""

return urllib.parse.quote(f"{font.postscript_name}-{glyph:x}")

def get_text_width_height_descent(self, s, prop, ismath):

fontsize = prop.get_size_in_points()

if ismath == "TeX":

return TexManager().get_text_width_height_descent(s, fontsize)

scale = fontsize / self.FONT_SCALE

if ismath:

prop = prop.copy()

prop.set_size(self.FONT_SCALE)

width, height, descent, *_ = \

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=LoadFlags.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

def get_text_path(self, prop, s, ismath=False, *, features=None, language=None):

"""

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.

language : str, optional

The language of the text in a format accepted by libraqm, namely `a BCP47

language code <https://www.w3.org/International/articles/language-tags/>`_.

Returns

-------

verts : list

A list of arrays containing the (x, 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.text import TextToPath

from matplotlib.font_manager import FontProperties

fp = FontProperties(family="Comic Neue", 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, features=features, language=language)

else:

glyph_info, glyph_map, rects = self.get_glyphs_mathtext(prop, s)

verts, codes = [], []

for glyph_repr, xposition, yposition, scale in glyph_info:

verts1, codes1 = glyph_map[glyph_repr]

verts.extend(verts1 * scale + [xposition, yposition])

codes.extend(codes1)

for verts1, codes1 in rects:

verts.extend(verts1)

codes.extend(codes1)

# Make sure an empty string or one with nothing to print

# (e.g. only spaces & newlines) will be valid/empty path

if not verts:

verts = np.empty((0, 2))

return verts, codes

def get_glyphs_with_font(self, font, s, glyph_map=None,

return_new_glyphs_only=False, *, features=None,

language=None):

"""

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 = []

ypositions = []

glyph_reprs = []

for item in _text_helpers.layout(s, font, features=features, language=language):

glyph_repr = self._get_glyph_repr(item.ft_object, item.glyph_index)

glyph_reprs.append(glyph_repr)

xpositions.append(item.x)

ypositions.append(item.y)

if glyph_repr not in glyph_map:

glyph_map_new[glyph_repr] = item.ft_object.get_path()

sizes = [1.] * len(xpositions)

rects = []

return (list(zip(glyph_reprs, xpositions, ypositions, sizes)),

glyph_map_new, rects)

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_reprs = []

sizes = []

for font, fontsize, ccode, glyph_index, ox, oy in glyphs:

glyph_repr = self._get_glyph_repr(font, glyph_index)

if glyph_repr not in glyph_map:

font.clear()

font.set_size(self.FONT_SCALE, self.DPI)

font.load_glyph(glyph_index, flags=LoadFlags.NO_HINTING)

glyph_map_new[glyph_repr] = font.get_path()

xpositions.append(ox)

ypositions.append(oy)

glyph_reprs.append(glyph_repr)

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_reprs, xpositions, ypositions, sizes)),

glyph_map_new, myrects)

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 = 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_reprs, xpositions, ypositions, sizes = [], [], [], []

# Gather font information and do some setup for combining

# characters into strings.

for text in page.text:

font = get_font(text.font.resolve_path())

if text.font.subfont:

raise NotImplementedError("Indexing TTC fonts is not supported yet")

glyph_repr = self._get_glyph_repr(font, text.index)

if glyph_repr not in glyph_map:

font.clear()

font.set_size(self.FONT_SCALE, self.DPI)

font.load_glyph(text.index, flags=LoadFlags.TARGET_LIGHT)

glyph_map_new[glyph_repr] = font.get_path()

glyph_reprs.append(glyph_repr)

xpositions.append(text.x)

ypositions.append(text.y)

sizes.append(text.font_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_reprs, xpositions, ypositions, sizes)),

glyph_map_new, myrects)

text_to_path = TextToPath()

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<customizing-with-dynamic-rc-settings>`.

_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.text 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)

super().__init__(

*text_to_path.get_text_path(prop, s, ismath=ismath),

_interpolation_steps=_interpolation_steps,

readonly=True)

self._should_simplify = False

def set_size(self, size):

"""Set the text size."""

self._size = size

self._invalid = True

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._cached_vertices.flags.writeable = False

self._invalid = False

matplotlib/lib/matplotlib/textpath.py at v3.11.2 · matplotlib/matplotlib · GitHub

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