From f371932eea98268a247b062fd9845e9602d2a626 Mon Sep 17 00:00:00 2001
From: ousttrue <ousttrue@gmail.com>
Date: Fri, 17 Sep 2021 20:40:19 +0900
Subject: [PATCH] TextureTransform.VerticalFlipScaleOffset

---
 .../UniGLTF/IO/MaterialIO/MaterialExporter.cs |  2 +-
 .../UniGLTF/IO/MaterialIO/TextureTransform.cs | 22 +++++++++++++++++++
 .../IO/MaterialIO/TextureTransform.cs.meta    | 11 ++++++++++
 .../IO/TextureIO/GltfTextureImporter.cs       |  4 +---
 .../Samples/ScreenSpace/ScaleOffset.cs        | 22 ++++++-------------
 5 files changed, 42 insertions(+), 19 deletions(-)
 create mode 100644 Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs
 create mode 100644 Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs.meta

diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/MaterialExporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/MaterialExporter.cs
index 14a14cec3..551fc7957 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/MaterialExporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/MaterialExporter.cs
@@ -206,7 +206,7 @@ namespace UniGLTF
             {
                 var offset = m.GetTextureOffset(propertyName);
                 var scale = m.GetTextureScale(propertyName);
-                offset.y = 1.0f - offset.y - scale.y;
+                (scale, offset) = TextureTransform.VerticalFlipScaleOffset(scale, offset);
 
                 glTF_KHR_texture_transform.Serialize(textureInfo, (offset.x, offset.y), (scale.x, scale.y));
             }
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs
new file mode 100644
index 000000000..214a2b2ee
--- /dev/null
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs
@@ -0,0 +1,22 @@
+
+
+using UnityEngine;
+
+namespace UniGLTF
+{
+    public static class TextureTransform
+    {
+        /// <summary>
+        // UV Coordinate Conversion: glTF(top-left origin) to Unity(bottom-left origin)
+        /// https://github.com/vrm-c/UniVRM/issues/930
+        /// offset.y = 1.0f - offset.y - scale.y;
+        /// </summary>
+        /// <param name="s"></param>
+        /// <param name="o"></param>
+        /// <returns></returns>
+        public static (Vector2, Vector2) VerticalFlipScaleOffset(Vector2 s, Vector2 o)
+        {
+            return (new Vector2(s.x, s.y), new Vector2(o.x, 1.0f - o.y - s.y));
+        }
+    }
+}
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs.meta b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs.meta
new file mode 100644
index 000000000..2b967208c
--- /dev/null
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: a652f0fdb4236434a9a64aa35a3cb44f
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs
index 5cc96bc8c..68a89cb87 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs
@@ -118,9 +118,7 @@ namespace UniGLTF
                     scale = new Vector2(textureTransform.scale[0], textureTransform.scale[1]);
                 }
 
-                // UV Coordinate Conversion: glTF(top-left origin) to Unity(bottom-left origin)
-                // Formula: https://github.com/vrm-c/UniVRM/issues/930
-                offset.y = 1.0f - offset.y - scale.y;
+                (scale, offset) = TextureTransform.VerticalFlipScaleOffset(scale, offset);
             }
 
             return (offset, scale);
diff --git a/Assets/UniGLTF/Samples/ScreenSpace/ScaleOffset.cs b/Assets/UniGLTF/Samples/ScreenSpace/ScaleOffset.cs
index 557882fb6..a3fc728e5 100644
--- a/Assets/UniGLTF/Samples/ScreenSpace/ScaleOffset.cs
+++ b/Assets/UniGLTF/Samples/ScreenSpace/ScaleOffset.cs
@@ -1,6 +1,4 @@
-using System.Collections;
-using System.Collections.Generic;
-using UnityEngine;
+using UnityEngine;
 
 namespace UniGLTF.Samples
 {
@@ -34,23 +32,17 @@ namespace UniGLTF.Samples
 
         const string PROP_NAME = "_MainTex";
 
-        /// <summary>
-        /// https://github.com/vrm-c/UniVRM/issues/930
-        /// </summary>
-        /// <param name="s"></param>
-        /// <param name="o"></param>
-        /// <returns></returns>
-        public static (Vector2, Vector2) ConvScaleOffset(Vector2 s, Vector2 o)
-        {
-            return (new Vector2(s.x, s.y), new Vector2(o.x, 1 - o.y - s.y));
-        }
-
         void Execute()
         {
+            if (Unity == null || Gltf == null)
+            {
+                return;
+            }
+
             Unity.SetTextureScale(PROP_NAME, Scale);
             Unity.SetTextureOffset(PROP_NAME, Offset);
 
-            var (s, o) = ConvScaleOffset(Scale, Offset);
+            var (s, o) = TextureTransform.VerticalFlipScaleOffset(Scale, Offset);
 
             Gltf.SetTextureScale(PROP_NAME, s);
             Gltf.SetTextureOffset(PROP_NAME, o);