Add tests for the bad hinting of lowercase 'o'.

2 files changed, 28 insertions, 1 deletions

diff --git a/scripts/common_tests.py b/scripts/common_tests.py
index 14d761b..e766487 100644
--- a/scripts/common_tests.py
+++ b/scripts/common_tests.py
@@ -1,16 +1,33 @@
 """Common tests for different targets."""
 
 import glob
+import sys
 import unittest
 
 from fontTools import ttLib
 from nototools import coverage
 from nototools import font_data
 
+sys.path.append('./third_party/freetype-py')
+import freetype
+
 import layout
 import roboto_data
 
 
+def get_rendered_char_height(font_filename, font_size, char, target='mono'):
+    if target == 'mono':
+        render_params = freetype.FT_LOAD_TARGET_MONO
+    elif target == 'lcd':
+        render_params = freetype.FT_LOAD_TARGET_LCD
+    render_params |= freetype.FT_LOAD_RENDER
+
+    face = freetype.Face(font_filename)
+    face.set_char_size(font_size*64)
+    face.load_char(char, render_params)
+    return face.glyph.bitmap.rows
+
+
 def load_fonts(patterns, expected_count=None):
     """Load all fonts specified in the patterns.
 
diff --git a/scripts/run_web_tests.py b/scripts/run_web_tests.py
index 6b6adf9..fbeee0a 100755
--- a/scripts/run_web_tests.py
+++ b/scripts/run_web_tests.py
@@ -72,7 +72,7 @@ class TestHints(unittest.TestCase):
     """Tests hints."""
 
     def setUp(self):
-        _, self.fonts = FONTS
+        self.fontfiles, self.fonts = FONTS
 
     def test_existance_of_hints(self):
         """Tests all glyphs and makes sure non-composite ones have hints."""
@@ -89,6 +89,16 @@ class TestHints(unittest.TestCase):
 
         self.assertTrue(missing_hints == [])
 
+    def test_height_of_lowercase_o(self):
+        """Tests the height of the lowercase o in low resolutions."""
+        for fontfile in self.fontfiles:
+            for size in range(8, 30):  # Kind of arbitrary
+                o_height = common_tests.get_rendered_char_height(
+                    fontfile, size, 'o')
+                n_height = common_tests.get_rendered_char_height(
+                    fontfile, size, 'n')
+                self.assertEqual(o_height, n_height)
+
 
 if __name__ == '__main__':
     unittest.main()