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2842 lines (2425 loc) · 104 KB
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"""
Implementation details for :mod:`.mathtext`.
"""
from __future__ import annotations
import abc
import copy
import enum
import functools
import itertools
import logging
import math
import os
import re
import types
import unicodedata
import string
import textwrap
import typing as T
from typing import NamedTuple
import numpy as np
from numpy.typing import NDArray
from pyparsing import (
Empty, Forward, Literal, Group, NotAny, OneOrMore, Optional,
ParseBaseException, ParseException, ParseExpression, ParseFatalException,
ParserElement, ParseResults, QuotedString, Regex, StringEnd, ZeroOrMore,
pyparsing_common, nested_expr, one_of)
import matplotlib as mpl
from . import cbook
from ._mathtext_data import (
latex_to_bakoma, stix_glyph_fixes, stix_virtual_fonts, tex2uni)
from .font_manager import FontProperties, findfont, get_font
from .ft2font import FT2Font, Kerning, LoadFlags
if T.TYPE_CHECKING:
from collections.abc import Iterable
from .ft2font import Glyph
ParserElement.enable_packrat()
_log = logging.getLogger("matplotlib.mathtext")
##############################################################################
# FONTS
def get_unicode_index(symbol: str) -> int: # Publicly exported.
r"""
Return the integer index (from the Unicode table) of *symbol*.
Parameters
----------
symbol : str
A single (Unicode) character, a TeX command (e.g. r'\pi') or a Type1
symbol name (e.g. 'phi').
"""
try: # This will succeed if symbol is a single Unicode char
return ord(symbol)
except TypeError:
pass
try: # Is symbol a TeX symbol (i.e. \alpha)
return tex2uni[symbol.strip("\\")]
except KeyError as err:
raise ValueError(
f"{symbol!r} is not a valid Unicode character or TeX/Type1 symbol"
) from err
class VectorParse(NamedTuple):
"""
The namedtuple type returned by ``MathTextParser("path").parse(...)``.
Attributes
----------
width, height, depth : float
The global metrics.
glyphs : list
The glyphs including their positions.
rect : list
The list of rectangles.
"""
width: float
height: float
depth: float
glyphs: list[tuple[FT2Font, float, int, float, float]]
rects: list[tuple[float, float, float, float]]
VectorParse.__module__ = "matplotlib.mathtext"
class RasterParse(NamedTuple):
"""
The namedtuple type returned by ``MathTextParser("agg").parse(...)``.
Attributes
----------
ox, oy : float
The offsets are always zero.
width, height, depth : float
The global metrics.
image : 2D array of uint8
A raster image.
"""
ox: float
oy: float
width: float
height: float
depth: float
image: NDArray[np.uint8]
RasterParse.__module__ = "matplotlib.mathtext"
class Output:
r"""
Result of `ship`\ping a box: lists of positioned glyphs and rectangles.
This class is not exposed to end users, but converted to a `VectorParse` or
a `RasterParse` by `.MathTextParser.parse`.
"""
def __init__(self, box: Box):
self.box = box
self.glyphs: list[tuple[float, float, FontInfo]] = [] # (ox, oy, info)
self.rects: list[tuple[float, float, float, float]] = [] # (x1, y1, x2, y2)
def to_vector(self) -> VectorParse:
w, h, d = map(
np.ceil, [self.box.width, self.box.height, self.box.depth])
gs = [(info.font, info.fontsize, info.num, ox, h - oy + info.offset)
for ox, oy, info in self.glyphs]
rs = [(x1, h - y2, x2 - x1, y2 - y1)
for x1, y1, x2, y2 in self.rects]
return VectorParse(w, h + d, d, gs, rs)
def to_raster(self, *, antialiased: bool) -> RasterParse:
# Metrics y's and mathtext y's are oriented in opposite directions,
# hence the switch between ymin and ymax.
xmin = min([*[ox + info.metrics.xmin for ox, oy, info in self.glyphs],
*[x1 for x1, y1, x2, y2 in self.rects], 0]) - 1
ymin = min([*[oy - info.metrics.ymax for ox, oy, info in self.glyphs],
*[y1 for x1, y1, x2, y2 in self.rects], 0]) - 1
xmax = max([*[ox + info.metrics.xmax for ox, oy, info in self.glyphs],
*[x2 for x1, y1, x2, y2 in self.rects], 0]) + 1
ymax = max([*[oy - info.metrics.ymin for ox, oy, info in self.glyphs],
*[y2 for x1, y1, x2, y2 in self.rects], 0]) + 1
w = xmax - xmin
h = ymax - ymin - self.box.depth
d = ymax - ymin - self.box.height
image = np.zeros((math.ceil(h + max(d, 0)), math.ceil(w)), np.uint8)
# Ideally, we could just use self.glyphs and self.rects here, shifting
# their coordinates by (-xmin, -ymin), but this yields slightly
# different results due to floating point slop; shipping twice is the
# old approach and keeps baseline images backcompat.
shifted = ship(self.box, (-xmin, -ymin))
for ox, oy, info in shifted.glyphs:
info.font.draw_glyph_to_bitmap(
image, int(ox), int(oy - info.metrics.iceberg), info.glyph,
antialiased=antialiased)
for x1, y1, x2, y2 in shifted.rects:
height = max(int(y2 - y1) - 1, 0)
if height == 0:
center = (y2 + y1) / 2
y = int(center - (height + 1) / 2)
else:
y = int(y1)
x1 = math.floor(x1)
x2 = math.ceil(x2)
image[y:y+height+1, x1:x2+1] = 0xff
return RasterParse(0, 0, w, h + d, d, image)
class FontMetrics(NamedTuple):
"""
Metrics of a font.
Attributes
----------
advance : float
The advance distance (in points) of the glyph.
height : float
The height of the glyph in points.
width : float
The width of the glyph in points.
xmin, xmax, ymin, ymax : float
The ink rectangle of the glyph.
iceberg : float
The distance from the baseline to the top of the glyph. (This corresponds to
TeX's definition of "height".)
slanted : bool
Whether the glyph should be considered as "slanted" (currently used for kerning
sub/superscripts).
"""
advance: float
height: float
width: float
xmin: float
xmax: float
ymin: float
ymax: float
iceberg: float
slanted: bool
class FontInfo(NamedTuple):
font: FT2Font
fontsize: float
postscript_name: str
metrics: FontMetrics
num: int
glyph: Glyph
offset: float
class Fonts(abc.ABC):
"""
An abstract base class for a system of fonts to use for mathtext.
The class must be able to take symbol keys and font file names and
return the character metrics. It also delegates to a backend class
to do the actual drawing.
"""
def __init__(self, default_font_prop: FontProperties, load_glyph_flags: LoadFlags):
"""
Parameters
----------
default_font_prop : `~.font_manager.FontProperties`
The default non-math font, or the base font for Unicode (generic)
font rendering.
load_glyph_flags : `.ft2font.LoadFlags`
Flags passed to the glyph loader (e.g. ``FT_Load_Glyph`` and
``FT_Load_Char`` for FreeType-based fonts).
"""
self.default_font_prop = default_font_prop
self.load_glyph_flags = load_glyph_flags
def get_kern(self, font1: str, fontclass1: str, sym1: str, fontsize1: float,
font2: str, fontclass2: str, sym2: str, fontsize2: float,
dpi: float) -> float:
"""
Get the kerning distance for font between *sym1* and *sym2*.
See `~.Fonts.get_metrics` for a detailed description of the parameters.
"""
return 0.
def _get_font(self, font: str) -> FT2Font:
raise NotImplementedError
def _get_info(self, font: str, font_class: str, sym: str, fontsize: float,
dpi: float) -> FontInfo:
raise NotImplementedError
def get_metrics(self, font: str, font_class: str, sym: str, fontsize: float,
dpi: float) -> FontMetrics:
r"""
Parameters
----------
font : str
One of the TeX font names: "tt", "it", "rm", "cal", "sf", "bf",
"default", "regular", "bb", "frak", "scr". "default" and "regular"
are synonyms and use the non-math font.
font_class : str
One of the TeX font names (as for *font*), but **not** "bb",
"frak", or "scr". This is used to combine two font classes. The
only supported combination currently is ``get_metrics("frak", "bf",
...)``.
sym : str
A symbol in raw TeX form, e.g., "1", "x", or "\sigma".
fontsize : float
Font size in points.
dpi : float
Rendering dots-per-inch.
Returns
-------
FontMetrics
"""
info = self._get_info(font, font_class, sym, fontsize, dpi)
return info.metrics
def render_glyph(self, output: Output, ox: float, oy: float, font: str,
font_class: str, sym: str, fontsize: float, dpi: float) -> None:
"""
At position (*ox*, *oy*), draw the glyph specified by the remaining
parameters (see `get_metrics` for their detailed description).
"""
info = self._get_info(font, font_class, sym, fontsize, dpi)
output.glyphs.append((ox, oy, info))
def render_rect_filled(self, output: Output,
x1: float, y1: float, x2: float, y2: float) -> None:
"""
Draw a filled rectangle from (*x1*, *y1*) to (*x2*, *y2*).
"""
output.rects.append((x1, y1, x2, y2))
def get_xheight(self, font: str, fontsize: float, dpi: float) -> float:
"""
Get the xheight for the given *font* and *fontsize*.
"""
raise NotImplementedError()
def get_underline_thickness(self, font: str, fontsize: float, dpi: float) -> float:
"""
Get the line thickness that matches the given font. Used as a
base unit for drawing lines such as in a fraction or radical.
"""
raise NotImplementedError()
def get_sized_alternatives_for_symbol(self, fontname: str,
sym: str) -> list[tuple[str, str]]:
"""
Override if your font provides multiple sizes of the same
symbol. Should return a list of symbols matching *sym* in
various sizes. The expression renderer will select the most
appropriate size for a given situation from this list.
"""
return [(fontname, sym)]
class TruetypeFonts(Fonts, metaclass=abc.ABCMeta):
"""
A generic base class for all font setups that use Truetype fonts
(through FT2Font).
"""
def __init__(self, default_font_prop: FontProperties, load_glyph_flags: LoadFlags):
super().__init__(default_font_prop, load_glyph_flags)
# Per-instance cache.
self._get_info = functools.cache(self._get_info) # type: ignore[method-assign]
self._fonts = {}
self.fontmap: dict[str | int, str] = {}
filename = findfont(self.default_font_prop)
default_font = get_font(filename)
self._fonts['default'] = default_font
self._fonts['regular'] = default_font
def _get_font(self, font: str | int) -> FT2Font:
if font in self.fontmap:
basename = self.fontmap[font]
else:
# NOTE: An int is only passed by subclasses which have placed int keys into
# `self.fontmap`, so we must cast this to confirm it to typing.
basename = T.cast(str, font)
cached_font = self._fonts.get(basename)
if cached_font is None and os.path.exists(basename):
cached_font = get_font(basename)
self._fonts[basename] = cached_font
self._fonts[cached_font.postscript_name] = cached_font
self._fonts[cached_font.postscript_name.lower()] = cached_font
return T.cast(FT2Font, cached_font) # FIXME: Not sure this is guaranteed.
def _get_offset(self, font: FT2Font, glyph: Glyph, fontsize: float,
dpi: float) -> float:
if font.postscript_name == 'Cmex10':
return (glyph.height / 64 / 2) + (fontsize/3 * dpi/72)
return 0.
def _get_glyph(self, fontname: str, font_class: str,
sym: str) -> tuple[FT2Font, int, bool]:
raise NotImplementedError
# The return value of _get_info is cached per-instance.
def _get_info(self, fontname: str, font_class: str, sym: str, fontsize: float,
dpi: float) -> FontInfo:
font, num, slanted = self._get_glyph(fontname, font_class, sym)
font.set_size(fontsize, dpi)
glyph = font.load_char(num, flags=self.load_glyph_flags)
xmin, ymin, xmax, ymax = (val / 64 for val in glyph.bbox)
offset = self._get_offset(font, glyph, fontsize, dpi)
metrics = FontMetrics(
advance=glyph.linearHoriAdvance / 65536,
height=glyph.height / 64,
width=glyph.width / 64,
xmin=xmin,
xmax=xmax,
ymin=ymin + offset,
ymax=ymax + offset,
# iceberg is the equivalent of TeX's "height"
iceberg=glyph.horiBearingY / 64 + offset,
slanted=slanted
)
return FontInfo(
font=font,
fontsize=fontsize,
postscript_name=font.postscript_name,
metrics=metrics,
num=num,
glyph=glyph,
offset=offset
)
def get_xheight(self, fontname: str, fontsize: float, dpi: float) -> float:
font = self._get_font(fontname)
font.set_size(fontsize, dpi)
pclt = font.get_sfnt_table('pclt')
if pclt is None:
# Some fonts don't store the xHeight, so we do a poor man's xHeight
metrics = self.get_metrics(
fontname, mpl.rcParams['mathtext.default'], 'x', fontsize, dpi)
return metrics.iceberg
x_height = (pclt['xHeight'] / 64) * (fontsize / 12) * (dpi / 100)
return x_height
def get_underline_thickness(self, font: str, fontsize: float, dpi: float) -> float:
# This function used to grab underline thickness from the font
# metrics, but that information is just too un-reliable, so it
# is now hardcoded.
return ((0.75 / 12) * fontsize * dpi) / 72
def get_kern(self, font1: str, fontclass1: str, sym1: str, fontsize1: float,
font2: str, fontclass2: str, sym2: str, fontsize2: float,
dpi: float) -> float:
if font1 == font2 and fontsize1 == fontsize2:
info1 = self._get_info(font1, fontclass1, sym1, fontsize1, dpi)
info2 = self._get_info(font2, fontclass2, sym2, fontsize2, dpi)
font = info1.font
return font.get_kerning(info1.num, info2.num, Kerning.DEFAULT) / 64
return super().get_kern(font1, fontclass1, sym1, fontsize1,
font2, fontclass2, sym2, fontsize2, dpi)
class BakomaFonts(TruetypeFonts):
"""
Use the Bakoma TrueType fonts for rendering.
Symbols are strewn about a number of font files, each of which has
its own proprietary 8-bit encoding.
"""
_fontmap = {
'cal': 'cmsy10',
'rm': 'cmr10',
'tt': 'cmtt10',
'it': 'cmmi10',
'bf': 'cmb10',
'sf': 'cmss10',
'ex': 'cmex10',
}
def __init__(self, default_font_prop: FontProperties, load_glyph_flags: LoadFlags):
self._stix_fallback = StixFonts(default_font_prop, load_glyph_flags)
super().__init__(default_font_prop, load_glyph_flags)
for key, val in self._fontmap.items():
fullpath = findfont(val)
self.fontmap[key] = fullpath
self.fontmap[val] = fullpath
_slanted_symbols = set(r"\int \oint".split())
def _get_glyph(self, fontname: str, font_class: str,
sym: str) -> tuple[FT2Font, int, bool]:
font = None
if fontname in self.fontmap and sym in latex_to_bakoma:
basename, num = latex_to_bakoma[sym]
slanted = (basename == "cmmi10") or sym in self._slanted_symbols
font = self._get_font(basename)
elif len(sym) == 1:
slanted = (fontname == "it")
font = self._get_font(fontname)
if font is not None:
num = ord(sym)
if font is not None and font.get_char_index(num) != 0:
return font, num, slanted
else:
return self._stix_fallback._get_glyph(fontname, font_class, sym)
# The Bakoma fonts contain many pre-sized alternatives for the
# delimiters. The AutoSizedChar class will use these alternatives
# and select the best (closest sized) glyph.
_size_alternatives = {
'(': [('rm', '('), ('ex', '\xa1'), ('ex', '\xb3'),
('ex', '\xb5'), ('ex', '\xc3')],
')': [('rm', ')'), ('ex', '\xa2'), ('ex', '\xb4'),
('ex', '\xb6'), ('ex', '\x21')],
'{': [('cal', '{'), ('ex', '\xa9'), ('ex', '\x6e'),
('ex', '\xbd'), ('ex', '\x28')],
'}': [('cal', '}'), ('ex', '\xaa'), ('ex', '\x6f'),
('ex', '\xbe'), ('ex', '\x29')],
# The fourth size of '[' is mysteriously missing from the BaKoMa
# font, so I've omitted it for both '[' and ']'
'[': [('rm', '['), ('ex', '\xa3'), ('ex', '\x68'),
('ex', '\x22')],
']': [('rm', ']'), ('ex', '\xa4'), ('ex', '\x69'),
('ex', '\x23')],
r'\lfloor': [('ex', '\xa5'), ('ex', '\x6a'),
('ex', '\xb9'), ('ex', '\x24')],
r'\rfloor': [('ex', '\xa6'), ('ex', '\x6b'),
('ex', '\xba'), ('ex', '\x25')],
r'\lceil': [('ex', '\xa7'), ('ex', '\x6c'),
('ex', '\xbb'), ('ex', '\x26')],
r'\rceil': [('ex', '\xa8'), ('ex', '\x6d'),
('ex', '\xbc'), ('ex', '\x27')],
r'\langle': [('ex', '\xad'), ('ex', '\x44'),
('ex', '\xbf'), ('ex', '\x2a')],
r'\rangle': [('ex', '\xae'), ('ex', '\x45'),
('ex', '\xc0'), ('ex', '\x2b')],
r'\__sqrt__': [('ex', '\x70'), ('ex', '\x71'),
('ex', '\x72'), ('ex', '\x73')],
r'\backslash': [('ex', '\xb2'), ('ex', '\x2f'),
('ex', '\xc2'), ('ex', '\x2d')],
r'/': [('rm', '/'), ('ex', '\xb1'), ('ex', '\x2e'),
('ex', '\xcb'), ('ex', '\x2c')],
r'\widehat': [('rm', '\x5e'), ('ex', '\x62'), ('ex', '\x63'),
('ex', '\x64')],
r'\widetilde': [('rm', '\x7e'), ('ex', '\x65'), ('ex', '\x66'),
('ex', '\x67')],
r'<': [('cal', 'h'), ('ex', 'D')],
r'>': [('cal', 'i'), ('ex', 'E')]
}
for alias, target in [(r'\leftparen', '('),
(r'\rightparen', ')'),
(r'\leftbrace', '{'),
(r'\rightbrace', '}'),
(r'\leftbracket', '['),
(r'\rightbracket', ']'),
(r'\{', '{'),
(r'\}', '}'),
(r'\[', '['),
(r'\]', ']')]:
_size_alternatives[alias] = _size_alternatives[target]
def get_sized_alternatives_for_symbol(self, fontname: str,
sym: str) -> list[tuple[str, str]]:
return self._size_alternatives.get(sym, [(fontname, sym)])
class UnicodeFonts(TruetypeFonts):
"""
An abstract base class for handling Unicode fonts.
While some reasonably complete Unicode fonts (such as DejaVu) may
work in some situations, the only Unicode font I'm aware of with a
complete set of math symbols is STIX.
This class will "fallback" on the Bakoma fonts when a required
symbol cannot be found in the font.
"""
# Some glyphs are not present in the `cmr10` font, and must be brought in
# from `cmsy10`. Map the Unicode indices of those glyphs to the indices at
# which they are found in `cmsy10`.
_cmr10_substitutions = {
0x00D7: 0x00A3, # Multiplication sign.
0x2212: 0x00A1, # Minus sign.
}
def __init__(self, default_font_prop: FontProperties, load_glyph_flags: LoadFlags):
# This must come first so the backend's owner is set correctly
fallback_rc = mpl.rcParams['mathtext.fallback']
font_cls: type[TruetypeFonts] | None = {
'stix': StixFonts,
'stixsans': StixSansFonts,
'cm': BakomaFonts
}.get(fallback_rc)
self._fallback_font = (font_cls(default_font_prop, load_glyph_flags)
if font_cls else None)
super().__init__(default_font_prop, load_glyph_flags)
for texfont in "cal rm tt it bf sf bfit".split():
prop = mpl.rcParams['mathtext.' + texfont] # type: ignore[index]
font = findfont(prop)
self.fontmap[texfont] = font
prop = FontProperties('cmex10')
font = findfont(prop)
self.fontmap['ex'] = font
# include STIX sized alternatives for glyphs if fallback is STIX
if isinstance(self._fallback_font, StixFonts):
stixsizedaltfonts = {
0: 'STIXGeneral',
1: 'STIXSizeOneSym',
2: 'STIXSizeTwoSym',
3: 'STIXSizeThreeSym',
4: 'STIXSizeFourSym',
5: 'STIXSizeFiveSym'}
for size, name in stixsizedaltfonts.items():
fullpath = findfont(name)
self.fontmap[size] = fullpath
self.fontmap[name] = fullpath
_slanted_symbols = set(r"\int \oint".split())
def _map_virtual_font(self, fontname: str, font_class: str,
uniindex: int) -> tuple[str, int]:
return fontname, uniindex
def _get_glyph(self, fontname: str, font_class: str,
sym: str) -> tuple[FT2Font, int, bool]:
try:
uniindex = get_unicode_index(sym)
found_symbol = True
except ValueError:
uniindex = ord('?')
found_symbol = False
_log.warning("No TeX to Unicode mapping for %a.", sym)
fontname, uniindex = self._map_virtual_font(
fontname, font_class, uniindex)
new_fontname = fontname
# Only characters in the "Letter" class should be italicized in 'it'
# mode. Greek capital letters should be Roman.
if found_symbol:
if fontname == 'it' and uniindex < 0x10000:
char = chr(uniindex)
if (unicodedata.category(char)[0] != "L"
or unicodedata.name(char).startswith("GREEK CAPITAL")):
new_fontname = 'rm'
slanted = (new_fontname == 'it') or sym in self._slanted_symbols
found_symbol = False
font = self._get_font(new_fontname)
if font is not None:
if (uniindex in self._cmr10_substitutions
and font.family_name == "cmr10"):
font = get_font(
cbook._get_data_path("fonts/ttf/cmsy10.ttf"))
uniindex = self._cmr10_substitutions[uniindex]
glyphindex = font.get_char_index(uniindex)
if glyphindex != 0:
found_symbol = True
if not found_symbol:
if self._fallback_font:
if (fontname in ('it', 'regular')
and isinstance(self._fallback_font, StixFonts)):
fontname = 'rm'
g = self._fallback_font._get_glyph(fontname, font_class, sym)
family = g[0].family_name
if family in list(BakomaFonts._fontmap.values()):
family = "Computer Modern"
_log.info("Substituting symbol %s from %s", sym, family)
return g
else:
if (fontname in ('it', 'regular')
and isinstance(self, StixFonts)):
return self._get_glyph('rm', font_class, sym)
_log.warning("Font %r does not have a glyph for %a [U+%x], "
"substituting with a dummy symbol.",
new_fontname, sym, uniindex)
font = self._get_font('rm')
uniindex = 0xA4 # currency char, for lack of anything better
slanted = False
return font, uniindex, slanted
def get_sized_alternatives_for_symbol(self, fontname: str,
sym: str) -> list[tuple[str, str]]:
if self._fallback_font:
return self._fallback_font.get_sized_alternatives_for_symbol(
fontname, sym)
return [(fontname, sym)]
class DejaVuFonts(UnicodeFonts, metaclass=abc.ABCMeta):
_fontmap: dict[str | int, str] = {}
def __init__(self, default_font_prop: FontProperties, load_glyph_flags: LoadFlags):
# This must come first so the backend's owner is set correctly
if isinstance(self, DejaVuSerifFonts):
self._fallback_font = StixFonts(default_font_prop, load_glyph_flags)
else:
self._fallback_font = StixSansFonts(default_font_prop, load_glyph_flags)
self.bakoma = BakomaFonts(default_font_prop, load_glyph_flags)
TruetypeFonts.__init__(self, default_font_prop, load_glyph_flags)
# Include Stix sized alternatives for glyphs
self._fontmap.update({
1: 'STIXSizeOneSym',
2: 'STIXSizeTwoSym',
3: 'STIXSizeThreeSym',
4: 'STIXSizeFourSym',
5: 'STIXSizeFiveSym',
})
for key, name in self._fontmap.items():
fullpath = findfont(name)
self.fontmap[key] = fullpath
self.fontmap[name] = fullpath
def _get_glyph(self, fontname: str, font_class: str,
sym: str) -> tuple[FT2Font, int, bool]:
# Override prime symbol to use Bakoma.
if sym == r'\prime':
return self.bakoma._get_glyph(fontname, font_class, sym)
else:
# check whether the glyph is available in the display font
uniindex = get_unicode_index(sym)
font = self._get_font('ex')
if font is not None:
glyphindex = font.get_char_index(uniindex)
if glyphindex != 0:
return super()._get_glyph('ex', font_class, sym)
# otherwise return regular glyph
return super()._get_glyph(fontname, font_class, sym)
class DejaVuSerifFonts(DejaVuFonts):
"""
A font handling class for the DejaVu Serif fonts
If a glyph is not found it will fallback to Stix Serif
"""
_fontmap = {
'rm': 'DejaVu Serif',
'it': 'DejaVu Serif:italic',
'bf': 'DejaVu Serif:weight=bold',
'bfit': 'DejaVu Serif:italic:bold',
'sf': 'DejaVu Sans',
'tt': 'DejaVu Sans Mono',
'ex': 'DejaVu Serif Display',
0: 'DejaVu Serif',
}
class DejaVuSansFonts(DejaVuFonts):
"""
A font handling class for the DejaVu Sans fonts
If a glyph is not found it will fallback to Stix Sans
"""
_fontmap = {
'rm': 'DejaVu Sans',
'it': 'DejaVu Sans:italic',
'bf': 'DejaVu Sans:weight=bold',
'bfit': 'DejaVu Sans:italic:bold',
'sf': 'DejaVu Sans',
'tt': 'DejaVu Sans Mono',
'ex': 'DejaVu Sans Display',
0: 'DejaVu Sans',
}
class StixFonts(UnicodeFonts):
"""
A font handling class for the STIX fonts.
In addition to what UnicodeFonts provides, this class:
- supports "virtual fonts" which are complete alpha numeric
character sets with different font styles at special Unicode
code points, such as "Blackboard".
- handles sized alternative characters for the STIXSizeX fonts.
"""
_fontmap: dict[str | int, str] = {
'rm': 'STIXGeneral',
'it': 'STIXGeneral:italic',
'bf': 'STIXGeneral:weight=bold',
'bfit': 'STIXGeneral:italic:bold',
'nonunirm': 'STIXNonUnicode',
'nonuniit': 'STIXNonUnicode:italic',
'nonunibf': 'STIXNonUnicode:weight=bold',
0: 'STIXGeneral',
1: 'STIXSizeOneSym',
2: 'STIXSizeTwoSym',
3: 'STIXSizeThreeSym',
4: 'STIXSizeFourSym',
5: 'STIXSizeFiveSym',
}
_fallback_font = None
_sans = False
def __init__(self, default_font_prop: FontProperties, load_glyph_flags: LoadFlags):
TruetypeFonts.__init__(self, default_font_prop, load_glyph_flags)
for key, name in self._fontmap.items():
fullpath = findfont(name)
self.fontmap[key] = fullpath
self.fontmap[name] = fullpath
def _map_virtual_font(self, fontname: str, font_class: str,
uniindex: int) -> tuple[str, int]:
# Handle these "fonts" that are actually embedded in
# other fonts.
font_mapping = stix_virtual_fonts.get(fontname)
if (self._sans and font_mapping is None
and fontname not in ('regular', 'default')):
font_mapping = stix_virtual_fonts['sf']
doing_sans_conversion = True
else:
doing_sans_conversion = False
if isinstance(font_mapping, dict):
try:
mapping = font_mapping[font_class]
except KeyError:
mapping = font_mapping['rm']
elif isinstance(font_mapping, list):
mapping = font_mapping
else:
mapping = None
if mapping is not None:
# Binary search for the source glyph
lo = 0
hi = len(mapping)
while lo < hi:
mid = (lo+hi)//2
range = mapping[mid]
if uniindex < range[0]:
hi = mid
elif uniindex <= range[1]:
break
else:
lo = mid + 1
if range[0] <= uniindex <= range[1]:
uniindex = uniindex - range[0] + range[3]
fontname = range[2]
elif not doing_sans_conversion:
# This will generate a dummy character
uniindex = 0x1
fontname = mpl.rcParams['mathtext.default']
# Fix some incorrect glyphs.
if fontname in ('rm', 'it'):
uniindex = stix_glyph_fixes.get(uniindex, uniindex)
# Handle private use area glyphs
if fontname in ('it', 'rm', 'bf', 'bfit') and 0xe000 <= uniindex <= 0xf8ff:
fontname = 'nonuni' + fontname
return fontname, uniindex
@functools.cache
def get_sized_alternatives_for_symbol( # type: ignore[override]
self,
fontname: str,
sym: str) -> list[tuple[str, str]] | list[tuple[int, str]]:
fixes = {
'\\{': '{', '\\}': '}', '\\[': '[', '\\]': ']',
'<': '\N{MATHEMATICAL LEFT ANGLE BRACKET}',
'>': '\N{MATHEMATICAL RIGHT ANGLE BRACKET}',
}
sym = fixes.get(sym, sym)
try:
uniindex = get_unicode_index(sym)
except ValueError:
return [(fontname, sym)]
alternatives = [(i, chr(uniindex)) for i in range(6)
if self._get_font(i).get_char_index(uniindex) != 0]
# The largest size of the radical symbol in STIX has incorrect
# metrics that cause it to be disconnected from the stem.
if sym == r'\__sqrt__':
alternatives = alternatives[:-1]
return alternatives
class StixSansFonts(StixFonts):
"""
A font handling class for the STIX fonts (that uses sans-serif
characters by default).
"""
_sans = True
##############################################################################
# TeX-LIKE BOX MODEL
# The following is based directly on the document 'woven' from the
# TeX82 source code. This information is also available in printed
# form:
#
# Knuth, Donald E.. 1986. Computers and Typesetting, Volume B:
# TeX: The Program. Addison-Wesley Professional.
#
# The most relevant "chapters" are:
# Data structures for boxes and their friends
# Shipping pages out (ship())
# Packaging (hpack() and vpack())
# Data structures for math mode
# Subroutines for math mode
# Typesetting math formulas
#
# Many of the docstrings below refer to a numbered "node" in that
# book, e.g., node123
#
# Note that (as TeX) y increases downward, unlike many other parts of
# matplotlib.
# How much text shrinks when going to the next-smallest level.
SHRINK_FACTOR = 0.7
# The number of different sizes of chars to use, beyond which they will not
# get any smaller
NUM_SIZE_LEVELS = 6
class FontConstantsBase:
"""
A set of constants that controls how certain things, such as sub-
and superscripts are laid out. These are all metrics that can't
be reliably retrieved from the font metrics in the font itself.
"""
# Percentage of x-height of additional horiz. space after sub/superscripts
script_space: T.ClassVar[float] = 0.05
# Percentage of x-height that sub/superscripts drop below the baseline
subdrop: T.ClassVar[float] = 0.4
# Percentage of x-height that superscripts are raised from the baseline
sup1: T.ClassVar[float] = 0.7
# Percentage of x-height that subscripts drop below the baseline
sub1: T.ClassVar[float] = 0.3
# Percentage of x-height that subscripts drop below the baseline when a
# superscript is present
sub2: T.ClassVar[float] = 0.5
# Percentage of x-height that sub/superscripts are offset relative to the
# nucleus edge for non-slanted nuclei
delta: T.ClassVar[float] = 0.025
# Additional percentage of last character height above 2/3 of the
# x-height that superscripts are offset relative to the subscript
# for slanted nuclei
delta_slanted: T.ClassVar[float] = 0.2
# Percentage of x-height that superscripts and subscripts are offset for
# integrals
delta_integral: T.ClassVar[float] = 0.1
class ComputerModernFontConstants(FontConstantsBase):
script_space = 0.075
subdrop = 0.2
sup1 = 0.45
sub1 = 0.2
sub2 = 0.3
delta = 0.075
delta_slanted = 0.3
delta_integral = 0.3
class STIXFontConstants(FontConstantsBase):
script_space = 0.1
sup1 = 0.8
sub2 = 0.6
delta = 0.05
delta_slanted = 0.3
delta_integral = 0.3
class STIXSansFontConstants(FontConstantsBase):
script_space = 0.05
sup1 = 0.8
delta_slanted = 0.6
delta_integral = 0.3
class DejaVuSerifFontConstants(FontConstantsBase):
pass
class DejaVuSansFontConstants(FontConstantsBase):
pass
# Maps font family names to the FontConstantBase subclass to use
_font_constant_mapping = {
'DejaVu Sans': DejaVuSansFontConstants,
'DejaVu Sans Mono': DejaVuSansFontConstants,
'DejaVu Serif': DejaVuSerifFontConstants,
'cmb10': ComputerModernFontConstants,
'cmex10': ComputerModernFontConstants,
'cmmi10': ComputerModernFontConstants,
'cmr10': ComputerModernFontConstants,
'cmss10': ComputerModernFontConstants,
'cmsy10': ComputerModernFontConstants,
'cmtt10': ComputerModernFontConstants,
'STIXGeneral': STIXFontConstants,
'STIXNonUnicode': STIXFontConstants,
'STIXSizeFiveSym': STIXFontConstants,
'STIXSizeFourSym': STIXFontConstants,
'STIXSizeThreeSym': STIXFontConstants,
'STIXSizeTwoSym': STIXFontConstants,
'STIXSizeOneSym': STIXFontConstants,
# Map the fonts we used to ship, just for good measure
'Bitstream Vera Sans': DejaVuSansFontConstants,
'Bitstream Vera': DejaVuSansFontConstants,
}
def _get_font_constant_set(state: ParserState) -> type[FontConstantsBase]:
constants = _font_constant_mapping.get(