Add getlength and getbbox functions for TrueType fonts

Tests/fonts/LICENSE.txt

@@ -9,6 +9,7 @@ ter-x20b.pcf, from http://terminus-font.sourceforge.net/
 
 All of the above fonts are published under the SIL Open Font License (OFL) v1.1 (http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL), which allows you to copy, modify, and redistribute them if you need to.
 
+OpenSansCondensed-LightItalic.tt, from https://fonts.google.com/specimen/Open+Sans, under Apache License 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
 
 10x20-ISO8859-1.pcf, from https://packages.ubuntu.com/xenial/xfonts-base
 

Tests/test_imagefont.py

@@ -41,20 +41,23 @@ class TestImageFont:
             "getters": (13, 16),
             "mask": (107, 13),
             "multiline-anchor": 6,
+            "getlength": (36, 27, 27, 33),
         },
         (">=2.7",): {
             "multiline": 6.2,
             "textsize": 2.5,
             "getters": (12, 16),
             "mask": (108, 13),
             "multiline-anchor": 4,
+            "getlength": (36, 21, 24, 33),
         },
         "Default": {
             "multiline": 0.5,
             "textsize": 0.5,
             "getters": (12, 16),
             "mask": (108, 13),
             "multiline-anchor": 4,
+            "getlength": (36, 24, 24, 33),
         },
     }
 
@@ -198,6 +201,37 @@ def test_textsize_equal(self):
             # Epsilon ~.5 fails with FreeType 2.7
             assert_image_similar(im, target_img, self.metrics["textsize"])
 
+    @pytest.mark.parametrize(
+        "text,mode,font,size,length_basic_index,length_raqm",
+        (
+            # basic test
+            ("text", "L", "FreeMono.ttf", 15, 0, 36),
+            ("text", "1", "FreeMono.ttf", 15, 0, 36),
+            # issue 4177
+            ("rrr", "L", "DejaVuSans.ttf", 18, 1, 22.21875),
+            ("rrr", "1", "DejaVuSans.ttf", 18, 2, 22.21875),
+            # test 'l' not including extra margin
+            # using exact value 2047 / 64 for raqm, checked with debugger
+            ("ill", "L", "OpenSansCondensed-LightItalic.ttf", 63, 3, 31.984375),
+            ("ill", "1", "OpenSansCondensed-LightItalic.ttf", 63, 3, 31.984375),
+        ),
+    )
+    def test_getlength(self, text, mode, font, size, length_basic_index, length_raqm):
+        f = ImageFont.truetype(
+            "Tests/fonts/" + font, size, layout_engine=self.LAYOUT_ENGINE
+        )
+
+        im = Image.new(mode, (1, 1), 0)
+        d = ImageDraw.Draw(im)
+
+        if self.LAYOUT_ENGINE == ImageFont.LAYOUT_BASIC:
+            length = d.textlength(text, f)
+            assert length == self.metrics["getlength"][length_basic_index]
+        else:
+            # disable kerning, kerning metrics changed
+            length = d.textlength(text, f, features=["-kern"])
+            assert length == length_raqm
+
     def test_render_multiline(self):
         im = Image.new(mode="RGB", size=(300, 100))
         draw = ImageDraw.Draw(im)
@@ -754,23 +788,36 @@ def test_variation_set_by_axes(self):
         self._check_text(font, "Tests/images/variation_tiny_axes.png", 32.5)
 
     @pytest.mark.parametrize(
-        "anchor",
+        "anchor,left,left_old,top",
         (
             # test horizontal anchors
-            "ls",
-            "ms",
-            "rs",
+            ("ls", 0, 0, -36),
+            ("ms", -64, -65, -36),
+            ("rs", -128, -129, -36),
             # test vertical anchors
-            "ma",
-            "mt",
-            "mm",
-            "mb",
-            "md",
+            ("ma", -64, -65, 16),
+            ("mt", -64, -65, 0),
+            ("mm", -64, -65, -17),
+            ("mb", -64, -65, -44),
+            ("md", -64, -65, -51),
         ),
+        ids=("ls", "ms", "rs", "ma", "mt", "mm", "mb", "md"),
     )
-    def test_anchor(self, anchor):
+    def test_anchor(self, anchor, left, left_old, top):
         name, text = "quick", "Quick"
         path = f"Tests/images/test_anchor_{name}_{anchor}.png"
+
+        freetype = parse_version(features.version_module("freetype2"))
+        if freetype < parse_version("2.4"):
+            width, height = (129, 44)
+            left = left_old
+        elif self.LAYOUT_ENGINE == ImageFont.LAYOUT_RAQM:
+            width, height = (129, 44)
+        else:
+            width, height = (128, 44)
+
+        bbox_expected = (left, top, left + width, top + height)
+
         f = ImageFont.truetype(
             "Tests/fonts/NotoSans-Regular.ttf", 48, layout_engine=self.LAYOUT_ENGINE
         )
@@ -781,6 +828,8 @@ def test_anchor(self, anchor):
         d.line(((100, 0), (100, 200)), "gray")
         d.text((100, 100), text, fill="black", anchor=anchor, font=f)
 
+        assert d.textbbox((0, 0), text, f, anchor=anchor) == bbox_expected
+
         with Image.open(path) as expected:
             assert_image_similar(im, expected, 7)
 
@@ -831,14 +880,26 @@ def test_anchor_invalid(self):
 
         for anchor in ["", "l", "a", "lax", "sa", "xa", "lx"]:
             pytest.raises(ValueError, lambda: font.getmask2("hello", anchor=anchor))
+            pytest.raises(ValueError, lambda: font.getbbox("hello", anchor=anchor))
             pytest.raises(ValueError, lambda: d.text((0, 0), "hello", anchor=anchor))
+            pytest.raises(
+                ValueError, lambda: d.textbbox((0, 0), "hello", anchor=anchor)
+            )
             pytest.raises(
                 ValueError, lambda: d.multiline_text((0, 0), "foo\nbar", anchor=anchor)
             )
+            pytest.raises(
+                ValueError,
+                lambda: d.multiline_textbbox((0, 0), "foo\nbar", anchor=anchor),
+            )
         for anchor in ["lt", "lb"]:
             pytest.raises(
                 ValueError, lambda: d.multiline_text((0, 0), "foo\nbar", anchor=anchor)
             )
+            pytest.raises(
+                ValueError,
+                lambda: d.multiline_textbbox((0, 0), "foo\nbar", anchor=anchor),
+            )
 
 
 @skip_unless_feature("raqm")

Tests/test_imagefontctl.py

@@ -209,6 +209,59 @@ def test_language():
         assert_image_similar(im, target_img, 0.5)
 
 
+@pytest.mark.parametrize("mode", ("L", "1"))
+@pytest.mark.parametrize(
+    "text,direction,expected",
+    (
+        ("سلطنة عمان Oman", None, 173.703125),
+        ("سلطنة عمان Oman", "ltr", 173.703125),
+        ("Oman سلطنة عمان", "rtl", 173.703125),
+        ("English عربي", "rtl", 123.796875),
+        ("test", "ttb", 80.0),
+    ),
+    ids=("None", "ltr", "rtl2", "rtl", "ttb"),
+)
+def test_getlength(mode, text, direction, expected):
+    ttf = ImageFont.truetype(FONT_PATH, FONT_SIZE)
+    im = Image.new(mode, (1, 1), 0)
+    d = ImageDraw.Draw(im)
+
+    try:
+        assert d.textlength(text, ttf, direction) == expected
+    except ValueError as ex:
+        if (
+            direction == "ttb"
+            and str(ex) == "libraqm 0.7 or greater required for 'ttb' direction"
+        ):
+            pytest.skip("libraqm 0.7 or greater not available")
+
+
+@pytest.mark.parametrize("mode", ("L", "1"))
+@pytest.mark.parametrize("direction", ("ltr", "ttb"))
+@pytest.mark.parametrize(
+    "text",
+    ("i" + ("\u030C" * 15) + "i", "i" + "\u032C" * 15 + "i", "\u035Cii", "i\u0305i"),
+    ids=("caron-above", "caron-below", "double-breve", "overline"),
+)
+def test_getlength_combine(mode, direction, text):
+    if text == "i\u0305i" and direction == "ttb":
+        pytest.skip("fails with this font")
+
+    ttf = ImageFont.truetype("Tests/fonts/NotoSans-Regular.ttf", 48)
+
+    try:
+        target = ttf.getlength("ii", mode, direction)
+        actual = ttf.getlength(text, mode, direction)
+
+        assert actual == target
+    except ValueError as ex:
+        if (
+            direction == "ttb"
+            and str(ex) == "libraqm 0.7 or greater required for 'ttb' direction"
+        ):
+            pytest.skip("libraqm 0.7 or greater not available")
+
+
 @pytest.mark.parametrize("anchor", ("lt", "mm", "rb", "sm"))
 def test_anchor_ttb(anchor):
     if parse_version(features.version_module("freetype2")) < parse_version("2.5.1"):
@@ -298,6 +351,39 @@ def test_combine(name, text, dir, anchor, epsilon):
         assert_image_similar(im, expected, epsilon)
 
 
+@pytest.mark.parametrize(
+    "anchor,align",
+    (
+        ("lm", "left"),  # pass with getsize
+        ("lm", "center"),  # fail at 2.12
+        ("lm", "right"),  # fail at 2.57
+        ("mm", "left"),  # fail at 2.12
+        ("mm", "center"),  # pass with getsize
+        ("mm", "right"),  # fail at 2.12
+        ("rm", "left"),  # fail at 2.57
+        ("rm", "center"),  # fail at 2.12
+        ("rm", "right"),  # pass with getsize
+    ),
+)
+def test_combine_multiline(anchor, align):
+    # test that multiline text uses getlength, not getsize or getbbox
+
+    path = f"Tests/images/test_combine_multiline_{anchor}_{align}.png"
+    f = ImageFont.truetype("Tests/fonts/NotoSans-Regular.ttf", 48)
+    text = "i\u0305\u035C\ntext"  # i with overline and double breve, and a word
+
+    im = Image.new("RGB", (400, 400), "white")
+    d = ImageDraw.Draw(im)
+    d.line(((0, 200), (400, 200)), "gray")
+    d.line(((200, 0), (200, 400)), "gray")
+    bbox = d.multiline_textbbox((200, 200), text, anchor=anchor, font=f, align=align)
+    d.rectangle(bbox, outline="red")
+    d.multiline_text((200, 200), text, fill="black", anchor=anchor, font=f, align=align)
+
+    with Image.open(path) as expected:
+        assert_image_similar(im, expected, 0.015)
+
+
 def test_anchor_invalid_ttb():
     font = ImageFont.truetype(FONT_PATH, FONT_SIZE)
     im = Image.new("RGB", (100, 100), "white")
@@ -308,17 +394,34 @@ def test_anchor_invalid_ttb():
         pytest.raises(
             ValueError, lambda: font.getmask2("hello", anchor=anchor, direction="ttb")
         )
+        pytest.raises(
+            ValueError, lambda: font.getbbox("hello", anchor=anchor, direction="ttb")
+        )
         pytest.raises(
             ValueError, lambda: d.text((0, 0), "hello", anchor=anchor, direction="ttb")
         )
+        pytest.raises(
+            ValueError,
+            lambda: d.textbbox((0, 0), "hello", anchor=anchor, direction="ttb"),
+        )
         pytest.raises(
             ValueError,
             lambda: d.multiline_text(
                 (0, 0), "foo\nbar", anchor=anchor, direction="ttb"
             ),
         )
+        pytest.raises(
+            ValueError,
+            lambda: d.multiline_textbbox(
+                (0, 0), "foo\nbar", anchor=anchor, direction="ttb"
+            ),
+        )
     # ttb multiline text does not support anchors at all
     pytest.raises(
         ValueError,
         lambda: d.multiline_text((0, 0), "foo\nbar", anchor="mm", direction="ttb"),
     )
+    pytest.raises(
+        ValueError,
+        lambda: d.multiline_textbbox((0, 0), "foo\nbar", anchor="mm", direction="ttb"),
+    )