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Version 3.0.2
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Source code for matplotlib.textpath

from collections import OrderedDict
import functools
import urllib.parse
import warnings

import numpy as np

from matplotlib import cbook, dviread, font_manager, rcParams
from matplotlib.font_manager import FontProperties, get_font
from matplotlib.ft2font import (
    KERNING_DEFAULT, LOAD_NO_HINTING, LOAD_TARGET_LIGHT)
from matplotlib.mathtext import MathTextParser
from matplotlib.path import Path
from matplotlib.transforms import Affine2D


@functools.lru_cache(1)
def _get_adobe_standard_encoding():
    enc_name = dviread.find_tex_file('8a.enc')
    enc = dviread.Encoding(enc_name)
    return {c: i for i, c in enumerate(enc.encoding)}


[docs]class TextToPath(object): """ A class that convert a given text to a path using ttf fonts. """ FONT_SCALE = 100. DPI = 72 def __init__(self): self.mathtext_parser = MathTextParser('path') self._texmanager = None @property @cbook.deprecated("3.0") def tex_font_map(self): return dviread.PsfontsMap(dviread.find_tex_file('pdftex.map')) def _get_font(self, prop): """ find a ttf font. """ 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 glyph_to_path(self, font, currx=0.): """ convert the ft2font glyph to vertices and codes. """ verts, codes = font.get_path() if currx != 0.0: verts[:, 0] += currx return verts, codes
[docs] def get_text_width_height_descent(self, s, prop, ismath): if rcParams['text.usetex']: 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, usetex=False): """ Convert text *s* to path (a tuple of vertices and codes for matplotlib.path.Path). Parameters ---------- prop : `matplotlib.font_manager.FontProperties` instance The font properties for the text. s : str The text to be converted. usetex : bool, optional Whether to use tex rendering. Defaults to ``False``. ismath : bool, optional If True, use mathtext parser. Effective only if ``usetex == False``. Returns ------- verts, codes : tuple of lists *verts* is a list of numpy arrays containing the x and y coordinates of the vertices. *codes* is 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 not usetex: if 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) else: glyph_info, glyph_map, rects = self.get_glyphs_tex(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. """ # Mostly copied from backend_svg.py. lastgind = None currx = 0 xpositions = [] glyph_ids = [] if glyph_map is None: glyph_map = OrderedDict() if return_new_glyphs_only: glyph_map_new = OrderedDict() else: glyph_map_new = glyph_map # I'm not sure if I get kernings right. Needs to be verified. -JJL for c in s: ccode = ord(c) gind = font.get_char_index(ccode) if gind is None: ccode = ord('?') gind = 0 if lastgind is not None: kern = font.get_kerning(lastgind, gind, KERNING_DEFAULT) else: kern = 0 glyph = font.load_char(ccode, flags=LOAD_NO_HINTING) horiz_advance = glyph.linearHoriAdvance / 65536 char_id = self._get_char_id(font, ccode) if char_id not in glyph_map: glyph_map_new[char_id] = self.glyph_to_path(font) currx += kern / 64 xpositions.append(currx) glyph_ids.append(char_id) currx += horiz_advance lastgind = gind 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): """ convert the string *s* to vertices and codes by parsing it with mathtext. """ 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 = [] currx, curry = 0, 0 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) glyph = font.load_char(ccode, flags=LOAD_NO_HINTING) glyph_map_new[char_id] = self.glyph_to_path(font) 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 :class:`matplotlib.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 matplotlib's usetex mode. """ # codes are modstly borrowed from pdf backend. texmanager = self.get_texmanager() fontsize = prop.get_size_in_points() if hasattr(texmanager, "get_dvi"): dvifilelike = texmanager.get_dvi(s, self.FONT_SCALE) dvi = dviread.DviFromFileLike(dvifilelike, self.DPI) else: dvifile = texmanager.make_dvi(s, self.FONT_SCALE) dvi = dviread.Dvi(dvifile, self.DPI) with dvi: page = next(iter(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. # oldfont, seq = None, [] 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) if enc: charcode = enc.get(glyph, None) else: charcode = glyph ft2font_flag = LOAD_TARGET_LIGHT if charcode is not None: glyph0 = font.load_char(charcode, flags=ft2font_flag) else: warnings.warn("The glyph (%d) of font (%s) cannot be " "converted with the encoding. Glyph may " "be wrong" % (glyph, font.fname)) glyph0 = font.load_char(glyph, flags=ft2font_flag) glyph_map_new[char_id] = self.glyph_to_path(font) 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')) font_bunch = tex_font_map[texname] if font_bunch.filename is None: raise ValueError( ("No usable font file found for %s (%s). " "The font may lack a Type-1 version.") % (font_bunch.psname, texname)) font = get_font(font_bunch.filename) for charmap_name, charmap_code in [("ADOBE_CUSTOM", 1094992451), ("ADOBE_STANDARD", 1094995778)]: try: font.select_charmap(charmap_code) except (ValueError, RuntimeError): pass else: break else: charmap_name = "" warnings.warn("No supported encoding in font (%s)." % font_bunch.filename) if charmap_name == "ADOBE_STANDARD" and font_bunch.encoding: enc0 = dviread.Encoding(font_bunch.encoding) enc = {i: _get_adobe_standard_encoding().get(c, None) for i, c in enumerate(enc0.encoding)} else: enc = {} 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, *kl, **kwargs): 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 : integer, optional (Currently ignored) usetex : bool, optional Whether to use tex rendering. Defaults to ``False``. 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`. """ if prop is None: prop = FontProperties() if size is None: size = prop.get_size_in_points() self._xy = xy self.set_size(size) self._cached_vertices = None self._vertices, self._codes = self.text_get_vertices_codes( prop, s, usetex=usetex) self._should_simplify = False self._simplify_threshold = rcParams['path.simplify_threshold'] self._has_nonfinite = False self._interpolation_steps = _interpolation_steps
[docs] def set_size(self, size): """ set the size of the text """ self._size = size self._invalid = True
[docs] def get_size(self): """ get the size of the text """ return self._size
def _get_vertices(self): """ Return the cached path after updating it if necessary. """ self._revalidate_path() return self._cached_vertices def _get_codes(self): """ Return the codes """ return self._codes vertices = property(_get_vertices) codes = property(_get_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, self._size / text_to_path.FONT_SCALE).translate(*self._xy) self._cached_vertices = tr.transform(self._vertices) self._invalid = False
[docs] def is_math_text(self, s): """ Returns True if the given string *s* contains any mathtext. """ # copied from Text.is_math_text -JJL # Did we find an even number of non-escaped dollar signs? # If so, treat is as math text. dollar_count = s.count(r'$') - s.count(r'\$') even_dollars = (dollar_count > 0 and dollar_count % 2 == 0) if rcParams['text.usetex']: return s, 'TeX' if even_dollars: return s, True else: return s.replace(r'\$', '$'), False
[docs] def text_get_vertices_codes(self, prop, s, usetex): """ convert the string *s* to vertices and codes using the provided font property *prop*. Mostly copied from backend_svg.py. """ if usetex: verts, codes = text_to_path.get_text_path(prop, s, usetex=True) else: clean_line, ismath = self.is_math_text(s) verts, codes = text_to_path.get_text_path(prop, clean_line, ismath=ismath) return verts, codes