fix: hangul filler not working on OTF

.gitignore

@@ -20,3 +20,4 @@ OTFbuild/*.otf
 OTFbuild/*.woff
 OTFbuild/*.woff2
 *.fea
+*.xdp-*

OTFbuild/hangul.py

@@ -124,6 +124,16 @@ def compose_hangul(assets_dir) -> Dict[int, ExtractedGlyph]:
             result[pua] = ExtractedGlyph(pua, GlyphProps(width=w), bm)
             variant_count += 1
 
+    # Ensure jungseong filler PUA variants exist (col=0, rows 15-16).
+    # The filler has an empty bitmap so extract_hangul_jamo_variants skips
+    # it, but the vjmo GSUB lookup needs a PUA target to substitute to.
+    empty_bm = [[0] * cell_w for _ in range(cell_h)]
+    for row in [15, 16]:
+        pua = _pua_for_jamo_variant(0, row)
+        if pua not in result:
+            result[pua] = ExtractedGlyph(pua, GlyphProps(width=0), empty_bm)
+            variant_count += 1
+
     print(f"  Stored {variant_count} jamo variant glyphs in PUA (0x{HANGUL_PUA_BASE:05X}+)")
     print(f"  Total Hangul glyphs: {len(result)}")
     return result

OTFbuild/opentype_features.py

@@ -153,7 +153,7 @@ def _generate_hangul_gsub(glyphs, has, jamo_data):
 
     # Build codepoint lists (standard + extended jamo ranges)
     cho_ranges = list(range(0x1100, 0x115F)) + list(range(0xA960, 0xA97C))
-    jung_ranges = list(range(0x1161, 0x11A8)) + list(range(0xD7B0, 0xD7C7))
+    jung_ranges = list(range(0x1160, 0x11A8)) + list(range(0xD7B0, 0xD7C7))
     jong_ranges = list(range(0x11A8, 0x1200)) + list(range(0xD7CB, 0xD7FC))
 
     cho_cps = [cp for cp in cho_ranges if has(cp)]