Patch Small Capitals

scripts/11-slice.py

@@ -112,6 +112,40 @@ def update_flags(instance, weight, italic=False):
     instance['head'].macStyle = mac_style
 
 
+def patch_small_caps(font, style, italic=False):
+    gsub = font['GSUB'].table
+
+    lookup_list = []
+    for fr in [fr for fr in gsub.FeatureList.FeatureRecord if fr.FeatureTag == 'smcp']:
+        lookup_list += fr.Feature.LookupListIndex
+
+    for lookup_id in list(sorted(set(lookup_list))):
+        lookup = gsub.LookupList.Lookup[lookup_id]
+        for substitution_table in lookup.SubTable:
+            if substitution_table.LookupType != 1:
+                continue
+
+            if style == 'Serif' and not italic:
+                # lookup 35 sets different numbers for smallcaps
+                if lookup_id == 35:
+                    for g in list(substitution_table.mapping.keys()):
+                        del substitution_table.mapping[g]
+
+                # replace ß with appropriate glyph (not ss)
+                if 'germandbls' in substitution_table.mapping:
+                    substitution_table.mapping['germandbls'] = 'glyph01192'
+
+            if style == 'Sans' and not italic:
+                # lookup 88 sets different numbers for smallcaps
+                if lookup_id == 88:
+                    for g in list(substitution_table.mapping.keys()):
+                        del substitution_table.mapping[g]
+
+                # replace ß with appropriate glyph (not ss)
+                if 'germandbls' in substitution_table.mapping:
+                    substitution_table.mapping['germandbls'] = 'glyph01708'
+
+
 def slice_font(style, source, weight, adobe_weight, verbose_weight, italic=False):
     source_dir = _root_dir / 'adobe' / '-'.join(source.split(' ')[:2]).lower() / 'VAR'
     source_fnt = f'{source.replace(" ", "")}-{"Roman" if not italic else "Italic"}.ttf'
@@ -123,7 +157,7 @@ def slice_font(style, source, weight, adobe_weight, verbose_weight, italic=False
 
     update_name_table(instance, style, weight, verbose_weight, italic)
     update_flags(instance, weight, italic)
-    # TODO: patch small caps
+    patch_small_caps(instance, style, italic)
 
     output_dir = _root_dir / 'out' / f'gypt-{style.lower()}' / 'TTF'
     output_fnt = f'GYPT{style}-{(weight != 400 or not italic)*verbose_weight}{italic*"It"}.ttf'