From 41d1d58eb996de78020c309f34811d8c28d2408a Mon Sep 17 00:00:00 2001
From: Viktor Kovacs <viktorkovacs@gmail.com>
Date: Mon, 29 Mar 2021 15:23:09 +0200
Subject: [PATCH] Write utf-8 encoded json in binary gltf.

---
 source/export/exportergltf.js | 9 ++++-----
 source/io/bufferutils.js      | 6 ++++++
 test/tests/io_test.js         | 9 +++++++++
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/source/export/exportergltf.js b/source/export/exportergltf.js
index 5b3d6fc..709a489 100644
--- a/source/export/exportergltf.js
+++ b/source/export/exportergltf.js
@@ -137,8 +137,9 @@ OV.ExporterGltf = class extends OV.ExporterBase
         });
 
         let mainJsonString = JSON.stringify (mainJson);
-        let mainJsonBufferLength = mainJsonString.length;
-        let mainJsonBufferAlignedLength = AlignToBoundary (mainJsonString.length);
+        let mainJsonBuffer = OV.Utf8StringToArrayBuffer (mainJsonString);
+        let mainJsonBufferLength = mainJsonBuffer.byteLength;
+        let mainJsonBufferAlignedLength = AlignToBoundary (mainJsonBufferLength);
 
         let glbSize = 12 + 8 + mainJsonBufferAlignedLength + 8 + mainBinaryBufferAlignedLength;
         let glbWriter = new OV.BinaryWriter (glbSize, true);
@@ -149,9 +150,7 @@ OV.ExporterGltf = class extends OV.ExporterBase
 
         glbWriter.WriteUnsignedInteger32 (mainJsonBufferAlignedLength);
         glbWriter.WriteUnsignedInteger32 (0x4E4F534A);
-		for (let i = 0; i < mainJsonBufferLength; i++) {
-            glbWriter.WriteUnsignedCharacter8 (mainJsonString.charCodeAt (i));
-		}
+        glbWriter.WriteArrayBuffer (mainJsonBuffer);
         WriteCharacters (glbWriter, 32, mainJsonBufferAlignedLength - mainJsonBufferLength);
 
         glbWriter.WriteUnsignedInteger32 (mainBinaryBufferAlignedLength);
diff --git a/source/io/bufferutils.js b/source/io/bufferutils.js
index 17965e5..502999e 100644
--- a/source/io/bufferutils.js
+++ b/source/io/bufferutils.js
@@ -24,6 +24,12 @@ OV.AsciiStringToArrayBuffer = function (str)
 	return buffer;
 };
 
+OV.Utf8StringToArrayBuffer = function (str)
+{
+	let encoder = new TextEncoder ();
+	return encoder.encode (str);
+};
+
 OV.Base64DataURIToArrayBuffer = function (uri)
 {
 	let dataPrefix = 'data:';
diff --git a/test/tests/io_test.js b/test/tests/io_test.js
index a97d1de..9036397 100644
--- a/test/tests/io_test.js
+++ b/test/tests/io_test.js
@@ -89,4 +89,13 @@ describe ('IO Test', function () {
         assert.strictEqual (reader.ReadFloat32 (), 7.5);
         assert.strictEqual (reader.ReadDouble64 (), 8.5);
     });
+
+    it ('Utf8 Conversion', function () {
+        let str = 'example-\u2764-example';
+        let buffer = OV.Utf8StringToArrayBuffer (str);
+        assert.strictEqual (buffer.byteLength, 19);
+        let str2 = OV.ArrayBufferToUtf8String (buffer);
+        assert.strictEqual (str, str2);
+        assert.strictEqual (str.length, str2.length);
+    });    
 });