Discard local "relative" path to gltf image uri when located in same folder than model (#991)

* Update GLTFExporter.Texture.cs

* move test function to PathUtilities

* Update PathUtilities.cs

* Update PathUtilities.cs

Author: pandaGaume

SharedProjects/Babylon2GLTF/GLTFExporter.Texture.cs

@@ -177,7 +177,7 @@ private GLTFTextureInfo ExportTexture(BabylonTexture babylonTexture, GLTF gltf,
                     if (!string.IsNullOrWhiteSpace(exportParameters.textureFolder))
                     {
                         textureUri = PathUtilities.GetRelativePath( exportParameters.outputPath,exportParameters.textureFolder);
-                        textureUri = Path.Combine(textureUri, ImageName);
+                        textureUri = PathUtilities.IsLocalRootPath(textureUri) ? ImageName : Path.Combine(textureUri, ImageName);
                     }
                     gltfImage = new GLTFImage
                     {
@@ -266,7 +266,6 @@ private GLTFTextureInfo ExportTexture(BabylonTexture babylonTexture, GLTF gltf,
                 if (CheckIfImageIsRegistered(textureID))
                 {
                     var textureComponent = GetRegisteredTexture(textureID);
-
                     return textureComponent;
                 }
 
@@ -278,6 +277,7 @@ private GLTFTextureInfo ExportTexture(BabylonTexture babylonTexture, GLTF gltf,
             }
         }
 
+
         private string TextureTransformID(GLTFTextureInfo gltfTextureInfo)
         {
             if (gltfTextureInfo.extensions == null || !gltfTextureInfo.extensions.ContainsKey(KHR_texture_transform))

SharedProjects/Utilities/PathUtilities.cs

@@ -6,6 +6,9 @@ namespace Utilities
 {
     static class PathUtilities
     {
+        public static string LocalDir = ".";
+        public static string LocalDirPath = $"{LocalDir}{Path.DirectorySeparatorChar}";
+        public static string AltLocalDirPath = $"{LocalDir}{Path.AltDirectorySeparatorChar}";
 
         /// <summary>
         /// Creates a relative path from one file or folder to another. Input paths that are directories should have a trailing slash.
@@ -66,6 +69,8 @@ public static string VerifyLegalFileName(string fileName)
             return r.Replace(fileName, "_");
             //source: https://stackoverflow.com/a/146162/301388
         }
+
+        public static bool IsLocalRootPath(string path) => string.IsNullOrEmpty(path) || path.CompareTo(AltLocalDirPath) == 0 || path.CompareTo(LocalDirPath) == 0 || path.CompareTo(LocalDir) == 0;
     }