From c974b4ef4300bd7c3ccea510dd05b3f3dd6325f4 Mon Sep 17 00:00:00 2001
From: Jaremy Creechley <creechley@gmail.com>
Date: Wed, 15 Jul 2026 23:21:40 +0300
Subject: [PATCH] Support Unicode cmap platform records

---
 src/pixie/fontformats/opentype.nim |  6 +++---
 tests/test_fonts.nim               | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/pixie/fontformats/opentype.nim b/src/pixie/fontformats/opentype.nim
index 537257a6..05d2bad2 100644
--- a/src/pixie/fontformats/opentype.nim
+++ b/src/pixie/fontformats/opentype.nim
@@ -450,8 +450,8 @@ proc parseCmapTable(buf: string, offset: int): CmapTable =
     encodingRecord.offset = buf.readUint32(i + 4).swap()
     i += 8
 
-    if encodingRecord.platformID == 3:
-      # Windows
+    if encodingRecord.platformID in [0'u16, 3'u16]:
+      # Unicode or Windows
       var i = offset + encodingRecord.offset.int
       buf.eofCheck(i + 2)
 
@@ -563,7 +563,7 @@ proc parseCmapTable(buf: string, offset: int): CmapTable =
         # TODO implement other windows formats
         discard
     else:
-      # TODO implement other cmap platformIDs
+      # TODO implement legacy cmap platform IDs.
       discard
 
 proc parseHeadTable(buf: string, offset: int): HeadTable =
diff --git a/tests/test_fonts.nim b/tests/test_fonts.nim
index debaaa78..0c87491a 100644
--- a/tests/test_fonts.nim
+++ b/tests/test_fonts.nim
@@ -4,6 +4,21 @@ proc wh(image: Image): Vec2 =
   ## Return with and height as a size vector.
   vec2(image.width.float32, image.height.float32)
 
+block:
+  var data = readFile("tests/fonts/Ubuntu-Regular_1.ttf")
+  let
+    original = parseOpenType(data)
+    cmapOffset = original.tableRecords["cmap"].offset.int
+    encodingCount = data[cmapOffset + 2].ord shl 8 or data[cmapOffset + 3].ord
+
+  for index in 0 ..< encodingCount:
+    let recordOffset = cmapOffset + 4 + index * 8
+    data[recordOffset] = '\0'
+    data[recordOffset + 1] = '\0'
+
+  let unicodeOnly = parseOpenType(data)
+  doAssert unicodeOnly.hasGlyph('A'.Rune)
+
 block:
   var font = readFont("tests/fonts/NotoEmoji.otf")
   font.size = 26