pdf/ps: Support any font in a collection

Author: QuLogic

lib/matplotlib/backends/_backend_pdf_ps.py

@@ -42,7 +42,7 @@ def get_glyphs_subset(fontfile: str, glyphs: set[GlyphIndexType]) -> TTFont:
 
     Parameters
     ----------
-    fontfile : str
+    fontfile : FontPath
         Path to the font file
     glyphs : set[GlyphIndexType]
         Set of glyph indices to include in subset.
@@ -80,8 +80,7 @@ def get_glyphs_subset(fontfile: str, glyphs: set[GlyphIndexType]) -> TTFont:
         'xref',  # The cross-reference table (some Apple font tooling information).
     ]
     # if fontfile is a ttc, specify font number
-    if fontfile.endswith(".ttc"):
-        options.font_number = 0
+    options.font_number = fontfile.face_index
 
     font = subset.load_font(fontfile, options)
     subsetter = subset.Subsetter(options=options)
@@ -267,11 +266,12 @@ def track_glyph(self, font: FT2Font, chars: str | CharacterCodeType,
             charcode = chars
             chars = chr(chars)
 
-        glyph_map = self.glyph_maps.setdefault(font.fname, GlyphMap())
+        font_path = font_manager.FontPath(font.fname, font.face_index)
+        glyph_map = self.glyph_maps.setdefault(font_path, GlyphMap())
         if result := glyph_map.get(chars, glyph):
             return result
 
-        subset_maps = self.used.setdefault(font.fname, [{}])
+        subset_maps = self.used.setdefault(font_path, [{}])
         use_next_charmap = (
             # Multi-character glyphs always go in the non-0 subset.
             len(chars) > 1 or

lib/matplotlib/backends/backend_pdf.py

@@ -32,7 +32,7 @@
     RendererBase)
 from matplotlib.backends.backend_mixed import MixedModeRenderer
 from matplotlib.figure import Figure
-from matplotlib.font_manager import get_font, fontManager as _fontManager
+from matplotlib.font_manager import FontPath, get_font, fontManager as _fontManager
 from matplotlib._afm import AFM
 from matplotlib.ft2font import FT2Font, FaceFlags, LoadFlags, StyleFlags
 from matplotlib.transforms import Affine2D, BboxBase
@@ -894,8 +894,10 @@ def fontName(self, fontprop, subset=0):
         as the filename of the font.
         """
 
-        if isinstance(fontprop, str):
+        if isinstance(fontprop, FontPath):
             filenames = [fontprop]
+        elif isinstance(fontprop, str):
+            filenames = [FontPath(fontprop, 0)]
         elif mpl.rcParams['pdf.use14corefonts']:
             filenames = _fontManager._find_fonts_by_props(
                 fontprop, fontext='afm', directory=RendererPdf._afm_font_dir
@@ -935,7 +937,7 @@ def writeFonts(self):
             _log.debug('Embedding Type-1 font %s from dvi.', dvifont.texname)
             fonts[pdfname] = self._embedTeXFont(dvifont)
         for (filename, subset), Fx in sorted(self._fontNames.items()):
-            _log.debug('Embedding font %s:%d.', filename, subset)
+            _log.debug('Embedding font %r:%d.', filename, subset)
             if filename.endswith('.afm'):
                 # from pdf.use14corefonts
                 _log.debug('Writing AFM font.')
@@ -986,10 +988,11 @@ def _embedTeXFont(self, dvifont):
 
         # Reduce the font to only the glyphs used in the document, get the encoding
         # for that subset, and compute various properties based on the encoding.
-        charmap = self._character_tracker.used[dvifont.fname][0]
+        font_path = FontPath(dvifont.fname, dvifont.face_index)
+        charmap = self._character_tracker.used[font_path][0]
         chars = {
             # DVI type 1 fonts always map single glyph to single character.
-            ord(self._character_tracker.subset_to_unicode(dvifont.fname, 0, ccode))
+            ord(self._character_tracker.subset_to_unicode(font_path, 0, ccode))
             for ccode in charmap
         }
         t1font = t1font.subset(chars, self._get_subset_prefix(charmap.values()))
@@ -1241,12 +1244,12 @@ def embedTTFType42(font, subset_index, charmap, descriptor):
             wObject = self.reserveObject('Type 0 widths')
             toUnicodeMapObject = self.reserveObject('ToUnicode map')
 
-            _log.debug("SUBSET %s:%d characters: %s", filename, subset_index, charmap)
+            _log.debug("SUBSET %r:%d characters: %s", filename, subset_index, charmap)
             with _backend_pdf_ps.get_glyphs_subset(filename,
                                                    charmap.values()) as subset:
                 fontdata = _backend_pdf_ps.font_as_file(subset)
             _log.debug(
-                "SUBSET %s:%d %d -> %d", filename, subset_index,
+                "SUBSET %r:%d %d -> %d", filename, subset_index,
                 os.stat(filename).st_size, fontdata.getbuffer().nbytes
             )
 
@@ -2137,13 +2140,13 @@ def draw_mathtext(self, gc, x, y, s, prop, angle):
         for font, fontsize, ccode, glyph_index, ox, oy in glyphs:
             subset_index, subset_charcode = self.file._character_tracker.track_glyph(
                 font, ccode, glyph_index)
-            fontname = font.fname
+            font_path = FontPath(font.fname, font.face_index)
             self._setup_textpos(ox, oy, 0, oldx, oldy)
             oldx, oldy = ox, oy
-            if (fontname, subset_index, fontsize) != prev_font:
-                self.file.output(self.file.fontName(fontname, subset_index), fontsize,
+            if (font_path, subset_index, fontsize) != prev_font:
+                self.file.output(self.file.fontName(font_path, subset_index), fontsize,
                                  Op.selectfont)
-                prev_font = fontname, subset_index, fontsize
+                prev_font = font_path, subset_index, fontsize
             self.file.output(self._encode_glyphs([subset_charcode], fonttype),
                              Op.show)
         self.file.output(Op.end_text)
@@ -2338,7 +2341,9 @@ def output_singlebyte_chunk(kerns_or_chars):
                     item.ft_object, item.char, item.glyph_index)
                 if (item.ft_object, subset) != prev_font:
                     output_singlebyte_chunk(singlebyte_chunk)
-                    ft_name = self.file.fontName(item.ft_object.fname, subset)
+                    font_path = FontPath(item.ft_object.fname,
+                                         item.ft_object.face_index)
+                    ft_name = self.file.fontName(font_path, subset)
                     self.file.output(ft_name, fontsize, Op.selectfont)
                     self._setup_textpos(item.x, 0, 0, prev_start_x, 0, 0)
                     prev_font = (item.ft_object, subset)

lib/matplotlib/backends/backend_ps.py

@@ -94,7 +94,7 @@ def _font_to_ps_type3(font_path, subset_index, glyph_indices):
 
     Parameters
     ----------
-    font_path : path-like
+    font_path : FontPath
         Path to the font to be subsetted.
     subset_index : int
         The subset of the above font being created.
@@ -176,7 +176,7 @@ def _font_to_ps_type42(font_path, subset_index, glyph_indices, fh):
 
     Parameters
     ----------
-    font_path : path-like
+    font_path : FontPath
         Path to the font to be subsetted.
     subset_index : int
         The subset of the above font being created.
@@ -187,12 +187,8 @@ def _font_to_ps_type42(font_path, subset_index, glyph_indices, fh):
     """
     _log.debug("SUBSET %s:%d characters: %s", font_path, subset_index, glyph_indices)
     try:
-        kw = {}
-        # fix this once we support loading more fonts from a collection
-        # https://github.com/matplotlib/matplotlib/issues/3135#issuecomment-571085541
-        if font_path.endswith('.ttc'):
-            kw['fontNumber'] = 0
-        with (fontTools.ttLib.TTFont(font_path, **kw) as font,
+        with (fontTools.ttLib.TTFont(font_path.path,
+                                     fontNumber=font_path.face_index) as font,
               _backend_pdf_ps.get_glyphs_subset(font_path, glyph_indices) as subset):
             fontdata = _backend_pdf_ps.font_as_file(subset).getvalue()
             _log.debug(

lib/matplotlib/dviread.py

@@ -719,6 +719,10 @@ def fname(self):
         """A fake filename"""
         return self.texname.decode('latin-1')
 
+    @property
+    def face_index(self):  # For compatibility with FT2Font.
+        return 0
+
     def _get_fontmap(self, string):
         """Get the mapping from characters to the font that includes them.
 

lib/matplotlib/dviread.pyi

@@ -78,6 +78,8 @@ class DviFont:
     def widths(self) -> list[int]: ...
     @property
     def fname(self) -> str: ...
+    @property
+    def face_index(self) -> int: ...
     def resolve_path(self) -> Path: ...
     @property
     def subfont(self) -> int: ...

lib/matplotlib/tests/test_backend_pdf.py

@@ -3,6 +3,7 @@
 import io
 import os
 from pathlib import Path
+import string
 
 import numpy as np
 import pytest
@@ -365,7 +366,7 @@ def test_glyphs_subset():
 
     # subsetted FT2Font
     glyph_indices = {nosubcmap[ord(c)] for c in chars}
-    with get_glyphs_subset(fpath, glyph_indices) as subset:
+    with get_glyphs_subset(fm.FontPath(fpath, 0), glyph_indices) as subset:
         subfont = FT2Font(font_as_file(subset))
     subfont.set_text(chars)
     subcmap = subfont.get_charmap()
@@ -402,6 +403,38 @@ def test_multi_font_type42():
              horizontalalignment='center', verticalalignment='center')
 
 
+@image_comparison(['ttc_type3.pdf'], style='mpl20')
+def test_ttc_type3():
+    fp = fm.FontProperties(family=['WenQuanYi Zen Hei'])
+    if Path(fm.findfont(fp)).name != 'wqy-zenhei.ttc':
+        pytest.skip('Font wqy-zenhei.ttc may be missing')
+
+    fonts = ['WenQuanYi Zen Hei', 'WenQuanYi Zen Hei Mono']
+    plt.rc('font', size=16)
+    plt.rc('pdf', fonttype=3)
+
+    figs = plt.figure(figsize=(7, len(fonts) / 2)).subfigures(len(fonts))
+    for font, fig in zip(fonts, figs):
+        fig.text(0.5, 0.5, f'{font}: {string.ascii_uppercase}', font=font,
+                 horizontalalignment='center', verticalalignment='center')
+
+
+@image_comparison(['ttc_type42.pdf'], style='mpl20')
+def test_ttc_type42():
+    fp = fm.FontProperties(family=['WenQuanYi Zen Hei'])
+    if Path(fm.findfont(fp)).name != 'wqy-zenhei.ttc':
+        pytest.skip('Font wqy-zenhei.ttc may be missing')
+
+    fonts = ['WenQuanYi Zen Hei', 'WenQuanYi Zen Hei Mono']
+    plt.rc('font', size=16)
+    plt.rc('pdf', fonttype=42)
+
+    figs = plt.figure(figsize=(7, len(fonts) / 2)).subfigures(len(fonts))
+    for font, fig in zip(fonts, figs):
+        fig.text(0.5, 0.5, f'{font}: {string.ascii_uppercase}', font=font,
+                 horizontalalignment='center', verticalalignment='center')
+
+
 @pytest.mark.parametrize('family_name, file_name',
                          [("Noto Sans", "NotoSans-Regular.otf"),
                           ("FreeMono", "FreeMono.otf")])

lib/matplotlib/tests/test_backend_ps.py

@@ -1,12 +1,14 @@
 from collections import Counter
 import io
+from pathlib import Path
 import re
+import string
 import tempfile
 
 import numpy as np
 import pytest
 
-from matplotlib import cbook, path, patheffects
+from matplotlib import cbook, font_manager, path, patheffects
 from matplotlib.figure import Figure
 from matplotlib.patches import Ellipse
 from matplotlib.testing import _gen_multi_font_text
@@ -340,6 +342,38 @@ def test_multi_font_type42():
              horizontalalignment='center', verticalalignment='center')
 
 
+@image_comparison(['ttc_type3.eps'], style='mpl20')
+def test_ttc_type3():
+    fp = font_manager.FontProperties(family=['WenQuanYi Zen Hei'])
+    if Path(font_manager.findfont(fp)).name != 'wqy-zenhei.ttc':
+        pytest.skip('Font wqy-zenhei.ttc may be missing')
+
+    fonts = ['WenQuanYi Zen Hei', 'WenQuanYi Zen Hei Mono']
+    plt.rc('font', size=16)
+    plt.rc('pdf', fonttype=3)
+
+    figs = plt.figure(figsize=(7, len(fonts) / 2)).subfigures(len(fonts))
+    for font, fig in zip(fonts, figs):
+        fig.text(0.5, 0.5, f'{font}: {string.ascii_uppercase}', font=font,
+                 horizontalalignment='center', verticalalignment='center')
+
+
+@image_comparison(['ttc_type42.eps'], style='mpl20')
+def test_ttc_type42():
+    fp = font_manager.FontProperties(family=['WenQuanYi Zen Hei'])
+    if Path(font_manager.findfont(fp)).name != 'wqy-zenhei.ttc':
+        pytest.skip('Font wqy-zenhei.ttc may be missing')
+
+    fonts = ['WenQuanYi Zen Hei', 'WenQuanYi Zen Hei Mono']
+    plt.rc('font', size=16)
+    plt.rc('pdf', fonttype=42)
+
+    figs = plt.figure(figsize=(7, len(fonts) / 2)).subfigures(len(fonts))
+    for font, fig in zip(fonts, figs):
+        fig.text(0.5, 0.5, f'{font}: {string.ascii_uppercase}', font=font,
+                 horizontalalignment='center', verticalalignment='center')
+
+
 @image_comparison(["scatter.eps"])
 def test_path_collection():
     rng = np.random.default_rng(19680801)