matplotlib · aitikgupta · Jul 25, 2021 · Jul 25, 2021 · Jul 25, 2021 · Jul 25, 2021
diff --git a/lib/matplotlib/_text_helpers.py b/lib/matplotlib/_text_helpers.py
@@ -9,7 +9,7 @@
 
 
 LayoutItem = dataclasses.make_dataclass(
-    "LayoutItem", ["char", "glyph_idx", "x", "prev_kern"])
+    "LayoutItem", ["ft_object", "char", "glyph_idx", "x", "prev_kern"])
 
 
 def warn_on_missing_glyph(codepoint):
@@ -63,6 +63,7 @@ def layout(string, font, *, kern_mode=KERNING_DEFAULT):
                 if prev_glyph_idx is not None else 0.)
         x += kern
         glyph = font.load_glyph(glyph_idx, flags=LOAD_NO_HINTING)
-        yield LayoutItem(char, glyph_idx, x, kern)
+        ft_object = font.get_glyph_to_font().get(glyph_idx, font)
+        yield LayoutItem(ft_object, char, glyph_idx, x, kern)
         x += glyph.linearHoriAdvance / 65536
         prev_glyph_idx = glyph_idx
diff --git a/lib/matplotlib/backends/_backend_pdf_ps.py b/lib/matplotlib/backends/_backend_pdf_ps.py
@@ -2,6 +2,7 @@
 Common functionality between the PDF and PS backends.
 """
 
+import os
 from io import BytesIO
 import functools
 
@@ -37,7 +38,11 @@ def get_glyphs_subset(fontfile, characters):
     options = subset.Options(glyph_names=True, recommended_glyphs=True)
 
     # prevent subsetting FontForge Timestamp and other tables
-    options.drop_tables += ['FFTM', 'PfEd']
+    options.drop_tables += ['FFTM', 'PfEd', 'BDF']
+
+    # if fontfile is a ttc, specify font number
+    if os.path.splitext(fontfile)[1] == ".ttc":
+        options.font_number = 0
 
     with subset.load_font(fontfile, options) as font:
         subsetter = subset.Subsetter(options=options)
@@ -136,7 +141,7 @@ def _get_font_afm(self, prop):
         return _cached_get_afm_from_fname(fname)
 
     def _get_font_ttf(self, prop):
-        fname = font_manager.findfont(prop)
+        fname = font_manager.find_fontsprop(prop)
         font = font_manager.get_font(fname)
         font.clear()
         font.set_size(prop.get_size_in_points(), 72)

diff --git a/lib/matplotlib/backends/backend_agg.py b/lib/matplotlib/backends/backend_agg.py
@@ -35,7 +35,7 @@
 from matplotlib.backend_bases import (
     _Backend, _check_savefig_extra_args, FigureCanvasBase, FigureManagerBase,
     RendererBase)
-from matplotlib.font_manager import findfont, get_font
+from matplotlib.font_manager import find_fontsprop, get_font
 from matplotlib.ft2font import (LOAD_FORCE_AUTOHINT, LOAD_NO_HINTING,
                                 LOAD_DEFAULT, LOAD_NO_AUTOHINT)
 from matplotlib.mathtext import MathTextParser
@@ -251,7 +251,7 @@ def _get_agg_font(self, prop):
         """
         Get the font for text instance t, caching for efficiency
         """
-        fname = findfont(prop)
+        fname = find_fontsprop(prop)
         font = get_font(fname)
 
         font.clear()

diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
@@ -33,7 +33,7 @@
     GraphicsContextBase, RendererBase)
 from matplotlib.backends.backend_mixed import MixedModeRenderer
 from matplotlib.figure import Figure
-from matplotlib.font_manager import findfont, get_font
+from matplotlib.font_manager import findfont, find_fontsprop, get_font
 from matplotlib.afm import AFM
 import matplotlib.type1font as type1font
 import matplotlib.dviread as dviread
@@ -861,20 +861,28 @@ def fontName(self, fontprop):
         """
 
         if isinstance(fontprop, str):
-            filename = fontprop
+            filenames = [fontprop]
         elif mpl.rcParams['pdf.use14corefonts']:
-            filename = findfont(
-                fontprop, fontext='afm', directory=RendererPdf._afm_font_dir)
+            filenames = find_fontsprop(
+                fontprop, fontext='afm', directory=RendererPdf._afm_font_dir
+            ).values()
         else:
-            filename = findfont(fontprop)
-
-        Fx = self.fontNames.get(filename)
-        if Fx is None:
-            Fx = next(self._internal_font_seq)
-            self.fontNames[filename] = Fx
-            _log.debug('Assigning font %s = %r', Fx, filename)
-
-        return Fx
+            filenames = find_fontsprop(fontprop).values()
+        first_Fx = None
+        for fname in filenames:
+            Fx = self.fontNames.get(fname)
+            if not first_Fx:
+                first_Fx = Fx
+            if Fx is None:
+                Fx = next(self._internal_font_seq)
+                self.fontNames[fname] = Fx
+                _log.debug('Assigning font %s = %r', Fx, fname)
+                if not first_Fx:
+                    first_Fx = Fx
+
+        # find_fontsprop's first value always adheres to
+        # findfont's value, so technically no behaviour change
+        return first_Fx
 
     def dviFontName(self, dvifont):
         """
@@ -1143,7 +1151,6 @@ def get_char_width(charcode):
                 width = font.load_char(
                     s, flags=LOAD_NO_SCALE | LOAD_NO_HINTING).horiAdvance
                 return cvt(width)
-
             with warnings.catch_warnings():
                 # Ignore 'Required glyph missing from current font' warning
                 # from ft2font: here we're just building the widths table, but
@@ -2331,7 +2338,9 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
             fonttype = 1
         else:
             font = self._get_font_ttf(prop)
-            self.file._character_tracker.track(font, s)
+            char_to_font = font.fill_glyphs(s)
+            for char, font in char_to_font.items():
+                self.file._character_tracker.track(font, chr(char))
             fonttype = mpl.rcParams['pdf.fonttype']
 
         if gc.get_url() is not None:
@@ -2371,22 +2380,27 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
         # the regular text show command (TJ) with appropriate kerning between
         # chunks, whereas multibyte characters use the XObject command (Do).
         else:
-            # List of (start_x, [prev_kern, char, char, ...]), w/o zero kerns.
+            # List of (ft_object, start_x, [prev_kern, char, char, ...]),
+            # w/o zero kerns.
             singlebyte_chunks = []
-            # List of (start_x, glyph_index).
+            # List of (ft_object, start_x, glyph_index).
             multibyte_glyphs = []
             prev_was_multibyte = True
+            prev_font = font
             for item in _text_helpers.layout(
                     s, font, kern_mode=KERNING_UNFITTED):
                 if _font_supports_glyph(fonttype, ord(item.char)):
-                    if prev_was_multibyte:
-                        singlebyte_chunks.append((item.x, []))
+                    if prev_was_multibyte or item.ft_object != prev_font:
+                        singlebyte_chunks.append((item.ft_object, item.x, []))
+                        prev_font = item.ft_object
                     if item.prev_kern:
-                        singlebyte_chunks[-1][1].append(item.prev_kern)
-                    singlebyte_chunks[-1][1].append(item.char)
+                        singlebyte_chunks[-1][2].append(item.prev_kern)
+                    singlebyte_chunks[-1][2].append(item.char)
                     prev_was_multibyte = False
                 else:
-                    multibyte_glyphs.append((item.x, item.glyph_idx))
+                    multibyte_glyphs.append(
+                        (item.ft_object, item.x, item.glyph_idx)
+                    )
                     prev_was_multibyte = True
             # Do the rotation and global translation as a single matrix
             # concatenation up front
@@ -2396,10 +2410,12 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
                              -math.sin(a), math.cos(a),
                              x, y, Op.concat_matrix)
             # Emit all the 1-byte characters in a BT/ET group.
-            self.file.output(Op.begin_text,
-                             self.file.fontName(prop), fontsize, Op.selectfont)
+
+            self.file.output(Op.begin_text)
             prev_start_x = 0
-            for start_x, kerns_or_chars in singlebyte_chunks:
+            for ft_object, start_x, kerns_or_chars in singlebyte_chunks:
+                ft_name = self.file.fontName(ft_object.fname)
+                self.file.output(ft_name, fontsize, Op.selectfont)
                 self._setup_textpos(start_x, 0, 0, prev_start_x, 0, 0)
                 self.file.output(
                     # See pdf spec "Text space details" for the 1000/fontsize
@@ -2411,14 +2427,16 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
                 prev_start_x = start_x
             self.file.output(Op.end_text)
             # Then emit all the multibyte characters, one at a time.
-            for start_x, glyph_idx in multibyte_glyphs:
-                self._draw_xobject_glyph(font, fontsize, glyph_idx, start_x, 0)
+            for ft_object, start_x, glyph_idx in multibyte_glyphs:
+                self._draw_xobject_glyph(
+                    ft_object, fontsize, glyph_idx, start_x, 0
+                )
             self.file.output(Op.grestore)
 
-    def _draw_xobject_glyph(self, font, fontsize, glyph_idx, x, y):
+    def _draw_xobject_glyph(self, ft_object, fontsize, glyph_idx, x, y):
         """Draw a multibyte character from a Type 3 font as an XObject."""
-        symbol_name = font.get_glyph_name(glyph_idx)
-        name = self.file._get_xobject_symbol_name(font.fname, symbol_name)
+        symbol_name = ft_object.get_glyph_name(glyph_idx)
+        name = self.file._get_xobject_symbol_name(ft_object.fname, symbol_name)
         self.file.output(
             Op.gsave,
             0.001 * fontsize, 0, 0, 0.001 * fontsize, x, y, Op.concat_matrix,

diff --git a/lib/matplotlib/font_manager.py b/lib/matplotlib/font_manager.py
@@ -23,6 +23,7 @@
 #   - setWeights function needs improvement
 #   - 'light' is an invalid weight value, remove it.
 
+from collections import OrderedDict
 import dataclasses
 from functools import lru_cache
 import json
@@ -1308,6 +1309,117 @@ def findfont(self, prop, fontext='ttf', directory=None,
             prop, fontext, directory, fallback_to_default, rebuild_if_missing,
             rc_params)
 
+    def find_fontsprop(self, prop, fontext='ttf', directory=None,
+                       fallback_to_default=True, rebuild_if_missing=True):
+        """
+        Find font families that most closely matches the given properties.
+
+        Parameters
+        ----------
+        prop : str or `~matplotlib.font_manager.FontProperties`
+            The font properties to search for. This can be either a
+            `.FontProperties` object or a string defining a
+            `fontconfig patterns`_.
+
+        fontext : {'ttf', 'afm'}, default: 'ttf'
+            The extension of the font file:
+
+            - 'ttf': TrueType and OpenType fonts (.ttf, .ttc, .otf)
+            - 'afm': Adobe Font Metrics (.afm)
+
+        directory : str, optional
+            If given, only search this directory and its subdirectories.
+
+        fallback_to_default : bool
+            If True, will fallback to the default font family (usually
+            "DejaVu Sans" or "Helvetica") if none of the families were found.
+
+        rebuild_if_missing : bool
+            Whether to rebuild the font cache and search again if the first
+            match appears to point to a nonexisting font (i.e., the font cache
+            contains outdated entries).
+
+        Returns
+        -------
+        OrderedDict
+            key, value pair of families and their corresponding filepaths.
+
+        Notes
+        -----
+        This is a plugin to original findfont API, which only returns a
+        single font for given font properties. Instead, this API returns
+        an OrderedDict containing multiple fonts and their filepaths which
+        closely match the given font properties.
+        Since this internally uses original API, there's no change
+        to the logic of performing the nearest neighbor search.
+        See `findfont` for more details.
+
+        """
+        # print("finding font!")
+
+        rc_params = tuple(tuple(rcParams[key]) for key in [
+            "font.serif", "font.sans-serif", "font.cursive", "font.fantasy",
+            "font.monospace"])
+
+        prop = FontProperties._from_any(prop)
+        ffamily = prop.get_family()
+
+        fpaths = OrderedDict()
+        for fidx in range(len(ffamily)):
+            cprop = prop.copy()
+
+            # set current prop's family
+            cprop.set_family(ffamily[fidx])
+
+            # do not fall back to default font
+            fpath = self._findfontsprop_cached(
+                ffamily[fidx], cprop, fontext, directory,
+                False, rebuild_if_missing, rc_params
+            )
+            if fpath:
+                fpaths[ffamily[fidx]] = fpath
+
+        # only add default family if no other font was found
+        # and fallback_to_default is enabled
+        if not fpaths:
+            if fallback_to_default:
+                dfamily = self.defaultFamily[fontext]
+                cprop = prop.copy().set_family(dfamily)
+                fpath = self._findfontsprop_cached(
+                    dfamily, cprop, fontext, directory,
+                    True, rebuild_if_missing, rc_params
+                )
+                fpaths[dfamily] = fpath
+            else:
+                raise ValueError("Failed to find any font, and fallback "
+                                 "to the default font was disabled.")
+
+        return fpaths
+
+    @lru_cache()
+    def _findfontsprop_cached(
+        self, family, prop, fontext, directory,
+        fallback_to_default, rebuild_if_missing, rc_params
+    ):
+        try:
+            return self._findfont_cached(
+                prop, fontext, directory, fallback_to_default,
+                rebuild_if_missing, rc_params
+            )
+        except ValueError:
+            if not fallback_to_default:
+                if family.lower() in font_family_aliases:
+                    _log.warning(
+                        "findfont: Generic family %r not found because "
+                        "none of the following families were found: %s",
+                        family,
+                        ", ".join(self._expand_aliases(family))
+                    )
+                else:
+                    _log.warning(
+                        'findfont: Font family \'%s\' not found.', family
+                    )
+
     @lru_cache()
     def _findfont_cached(self, prop, fontext, directory, fallback_to_default,
                          rebuild_if_missing, rc_params):
@@ -1401,9 +1513,21 @@ def is_opentype_cff_font(filename):
 
 
 @lru_cache(64)
-def _get_font(filename, hinting_factor, *, _kerning_factor, thread_id):
-    return ft2font.FT2Font(
-        filename, hinting_factor, _kerning_factor=_kerning_factor)
+def _get_font(fpaths, hinting_factor, *, _kerning_factor, thread_id):
+    ftobjects = []
+    for fpath in fpaths[1:]:
+        ftobject = ft2font.FT2Font(
+            fpath, hinting_factor,
+            _kerning_factor=_kerning_factor
+        )
+        ftobjects.append(ftobject)
+
+    ft2font_object = ft2font.FT2Font(
+        fpaths[0], hinting_factor,
+        _fallback_list=ftobjects,
+        _kerning_factor=_kerning_factor
+    )
+    return ft2font_object
 
 
 # FT2Font objects cannot be used across fork()s because they reference the same
@@ -1417,11 +1541,14 @@ def _get_font(filename, hinting_factor, *, _kerning_factor, thread_id):
 def get_font(filename, hinting_factor=None):
     # Resolving the path avoids embedding the font twice in pdf/ps output if a
     # single font is selected using two different relative paths.
-    filename = _cached_realpath(filename)
+    if isinstance(filename, OrderedDict):
+        paths = tuple(_cached_realpath(fname) for fname in filename.values())
+    else:
+        paths = (_cached_realpath(filename),)
     if hinting_factor is None:
         hinting_factor = rcParams['text.hinting_factor']
     # also key on the thread ID to prevent segfaults with multi-threading
-    return _get_font(filename, hinting_factor,
+    return _get_font(paths, hinting_factor,
                      _kerning_factor=rcParams['text.kerning_factor'],
                      thread_id=threading.get_ident())
 
@@ -1446,3 +1573,4 @@ def _load_fontmanager(*, try_read_cache=True):
 
 fontManager = _load_fontmanager()
 findfont = fontManager.findfont
+find_fontsprop = fontManager.find_fontsprop
diff --git a/lib/matplotlib/tests/baseline_images/test_agg/font_fallback.png b/lib/matplotlib/tests/baseline_images/test_agg/font_fallback.png
diff --git a/lib/matplotlib/tests/baseline_images/test_backend_pdf/multi_font_type3.pdf b/lib/matplotlib/tests/baseline_images/test_backend_pdf/multi_font_type3.pdf
diff --git a/lib/matplotlib/tests/baseline_images/test_backend_pdf/multi_font_type42.pdf b/lib/matplotlib/tests/baseline_images/test_backend_pdf/multi_font_type42.pdf