TST: Add tests for FT2Font charmaps

QuLogic · QuLogic · commit 6bad7f09906c · 2024-08-29T04:22:42.000-04:00
diff --git a/lib/matplotlib/tests/test_ft2font.py b/lib/matplotlib/tests/test_ft2font.py
@@ -176,6 +176,88 @@ def test_ft2font_clear():
     assert font.get_bitmap_offset() == (0, 0)
 
 
+def test_ft2font_charmaps():
+    def enc(name):
+        # We don't expose the encoding enum from FreeType, but can generate it here.
+        # For DejaVu, there are 5 charmaps, but only 2 have enum entries in FreeType.
+        e = 0
+        for x in name:
+            e <<= 8
+            e += ord(x)
+        return e
+
+    file = fm.findfont('DejaVu Sans')
+    font = ft2font.FT2Font(file)
+    assert font.num_charmaps == 5
+
+    # Unicode.
+    font.select_charmap(enc('unic'))
+    unic = font.get_charmap()
+    font.set_charmap(0)  # Unicode platform, Unicode BMP only.
+    after = font.get_charmap()
+    assert len(after) <= len(unic)
+    for chr, glyph in after.items():
+        assert unic[chr] == glyph == font.get_char_index(chr)
+    font.set_charmap(1)  # Unicode platform, modern subtable.
+    after = font.get_charmap()
+    assert unic == after
+    font.set_charmap(3)  # Windows platform, Unicode BMP only.
+    after = font.get_charmap()
+    assert len(after) <= len(unic)
+    for chr, glyph in after.items():
+        assert unic[chr] == glyph == font.get_char_index(chr)
+    font.set_charmap(4)  # Windows platform, Unicode full repertoire, modern subtable.
+    after = font.get_charmap()
+    assert unic == after
+
+    # This is just a random sample from FontForge.
+    glyph_names = {
+        'non-existent-glyph-name': 0,
+        'plusminus': 115,
+        'Racute': 278,
+        'perthousand': 2834,
+        'seveneighths': 3057,
+        'triagup': 3721,
+        'uni01D3': 405,
+        'uni0417': 939,
+        'uni2A02': 4464,
+        'u1D305': 5410,
+        'u1F0A1': 5784,
+    }
+    for name, index in glyph_names.items():
+        assert font.get_name_index(name) == index
+        if name == 'non-existent-glyph-name':
+            name = '.notdef'
+        # This doesn't always apply, but it does for DejaVu Sans.
+        assert font.get_glyph_name(index) == name
+
+    # Apple Roman.
+    font.select_charmap(enc('armn'))
+    armn = font.get_charmap()
+    font.set_charmap(2)  # Macintosh platform, Roman.
+    after = font.get_charmap()
+    assert armn == after
+    assert len(armn) <= 256  # 8-bit encoding.
+    # The first 128 characters of Apple Roman match ASCII, which also matches Unicode.
+    for o in range(1, 128):
+        if o not in armn or o not in unic:
+            continue
+        assert unic[o] == armn[o]
+    # Check a couple things outside the ASCII set that are different in each charset.
+    examples = [
+        # (Unicode, Macintosh)
+        (0x2020, 0xA0),  # Dagger.
+        (0x00B0, 0xA1),  # Degree symbol.
+        (0x00A3, 0xA3),  # Pound sign.
+        (0x00A7, 0xA4),  # Section sign.
+        (0x00B6, 0xA6),  # Pilcrow.
+        (0x221E, 0xB0),  # Infinity symbol.
+    ]
+    for u, m in examples:
+        # Though the encoding is different, the glyph should be the same.
+        assert unic[u] == armn[m]
+
+
 @pytest.mark.parametrize('family_name, file_name',
                           [("WenQuanYi Zen Hei",  "wqy-zenhei.ttc"),
                            ("Noto Sans CJK JP", "NotoSansCJK.ttc"),
