Update mincho.otf

This rewrites the `ascent` and `descent` values in the `hhea` table of
the font, so that the height of the surface returned by `TTF_Render*`
will be the same as the `ptsize` passed to `TTF_OpenFont`. (MTLc3m.ttf
already have this property.)

This fixes the text rendering issue in Tsumamigui2 and Yoru ga Kuru.

fonts/CMakeLists.txt

@@ -10,12 +10,9 @@ find_program(PYFTSUBSET_FOUND pyftsubset)
 
 if (PYFTSUBSET_FOUND)
   add_custom_target(fonts
-    pyftsubset SourceHanSerifJP-Regular.otf --text-file=uchars.txt --output-file=${CMAKE_CURRENT_SOURCE_DIR}/mincho.otf
-    DEPENDS uchars.txt SourceHanSerifJP-Regular.otf)
-
-  add_custom_command(OUTPUT uchars.txt
-    COMMAND uchars > uchars.txt)
-
-  add_custom_command(OUTPUT SourceHanSerifJP-Regular.otf
-    COMMAND wget -O SourceHanSerifJP-Regular.otf https://github.com/adobe-fonts/source-han-serif/blob/release/SubsetOTF/JP/SourceHanSerifJP-Regular.otf?raw=true)
+    COMMAND uchars > uchars.txt
+    COMMAND wget -O SourceHanSerifJP-Regular.otf https://github.com/adobe-fonts/source-han-serif/blob/release/SubsetOTF/JP/SourceHanSerifJP-Regular.otf?raw=true
+    COMMAND pyftsubset SourceHanSerifJP-Regular.otf --text-file=uchars.txt --output-file=subset.otf
+    COMMAND python3 ${CMAKE_CURRENT_SOURCE_DIR}/adjust_metrics.py subset.otf ${CMAKE_CURRENT_SOURCE_DIR}/mincho.otf
+    )
 endif()

fonts/adjust_metrics.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+import sys
+from fontTools.ttLib import TTFont
+
+if len(sys.argv) != 3:
+    print('Usage: adjust_metrics.py infile outfile')
+    exit(1)
+
+font = TTFont(sys.argv[1])
+
+hhea = font['hhea']
+os2 = font['OS/2']
+
+if hhea.ascent != os2.sTypoAscender:
+    print(f'Changing hhea.ascent from {hhea.ascent} to {os2.sTypoAscender}')
+    hhea.ascent = os2.sTypoAscender
+
+if hhea.descent != os2.sTypoDescender:
+    print(f'Changing hhea.descent from {hhea.descent} to {os2.sTypoDescender}')
+    hhea.descent = os2.sTypoDescender
+
+font.save(sys.argv[2])