Simplify HB_TAG

Munter · Jul 17, 2020 · 75ea80c · 75ea80c
1 parent 2e73139
commit 75ea80c
Showing 1 changed file with 10 additions and 8 deletions.
diff --git a/lib/subsetLocalFontWithHarfbuzz.js b/lib/subsetLocalFontWithHarfbuzz.js
@@ -5,13 +5,15 @@ const _ = require('lodash');
 const pathModule = require('path');
 const wawoff2 = require('wawoff2');
 const woffTool = require('woff2sfnt-sfnt2woff');
+const assert = require('assert');
 
-function HB_TAG(c1, c2, c3, c4) {
+function HB_TAG(chunkName) {
+  assert(chunkName.length === 4);
   return (
-    (c1.charCodeAt(0) << 24) |
-    (c2.charCodeAt(0) << 16) |
-    (c3.charCodeAt(0) << 8) |
-    c4.charCodeAt(0)
+    (chunkName.charCodeAt(0) << 24) |
+    (chunkName.charCodeAt(1) << 16) |
+    (chunkName.charCodeAt(2) << 8) |
+    chunkName.charCodeAt(3)
   );
 }
 
@@ -64,15 +66,15 @@ module.exports = async (originalFont, targetFormat, text) => {
   const inputGlyphs = exports.hb_subset_input_unicode_set(input);
   exports.hb_set_del(
     exports.hb_subset_input_drop_tables_set(input),
-    HB_TAG('G', 'S', 'U', 'B')
+    HB_TAG('GSUB')
   );
   exports.hb_set_del(
     exports.hb_subset_input_drop_tables_set(input),
-    HB_TAG('G', 'P', 'O', 'S')
+    HB_TAG('GPOS')
   );
   exports.hb_set_del(
     exports.hb_subset_input_drop_tables_set(input),
-    HB_TAG('G', 'D', 'E', 'F')
+    HB_TAG('GDEF')
   );
 
   exports.hb_set_union(inputGlyphs, glyphs);