update texture import settings

Runtime/PSXTexture2D.cs

@@ -125,6 +125,7 @@ namespace SplashEdit.RuntimeCode
         public static PSXTexture2D CreateFromTexture2D(Texture2D inputTexture, PSXBPP bitDepth)
         {
             PSXTexture2D psxTex = new PSXTexture2D();
+            Utils.SetTextureImporterFormat(inputTexture, true);
             
             psxTex.Width = inputTexture.width;
             psxTex.QuantizedWidth = bitDepth == PSXBPP.TEX_4BIT ? inputTexture.width / 4 :

Runtime/Utils.cs

@@ -308,6 +308,8 @@ namespace SplashEdit.RuntimeCode
 
     public static class Utils
     {
+        private static int MaxTextureSize => 256;
+
         public static (Rect, Rect) BufferForResolution(Vector2 selectedResolution, bool verticalLayout, Vector2 offset = default)
         {
             if (offset == default)
@@ -331,8 +333,28 @@ namespace SplashEdit.RuntimeCode
             };
         }
 
-
         public static byte Clamp0255(float v) => (byte)(Mathf.Clamp(v, 0, 255));
+
+        public static void SetTextureImporterFormat(Texture2D texture, bool isReadable)
+        {
+            if (texture == null)
+            {
+                return;
+            }
+            string assetPath = AssetDatabase.GetAssetPath(texture);
+            var tImporter = AssetImporter.GetAtPath(assetPath) as TextureImporter;
+            if (tImporter != null)
+            {
+                if (tImporter.maxTextureSize > MaxTextureSize)
+                {
+                    tImporter.maxTextureSize = MaxTextureSize;
+                }
+                tImporter.isReadable = isReadable;
+
+                AssetDatabase.ImportAsset(assetPath);
+                AssetDatabase.Refresh();
+            }
+        }
     }
 }