Fix Switch swizzle texture conversion and optimize Texture2DConverter

UnityPy/classes/legacy_patch/Texture2D.py

@@ -24,6 +24,7 @@ def _Texture2d_set_image(
 
     if not isinstance(img, Image.Image):
         img = Image.open(img)
+        assert isinstance(img, Image.Image)
 
     platform = self.object_reader.platform if self.object_reader is not None else 0
     img_data, tex_format = Texture2DConverter.image_to_texture2d(
@@ -70,6 +71,7 @@ def _Texture2D_get_image_data(self: Texture2D):
     if self.m_StreamData:
         from ...helpers.ResourceReader import get_resource_data
 
+        assert self.object_reader is not None
         return get_resource_data(
             self.m_StreamData.path,
             self.object_reader.assets_file,

UnityPy/classes/legacy_patch/Texture2DArray.py

@@ -15,9 +15,11 @@ def _Texture2DArray_get_images(self: Texture2DArray) -> List[Image.Image]:
     texture_format = GRAPHICS_TO_TEXTURE_MAP.get(GraphicsFormat(self.m_Format))
     if not texture_format:
         raise NotImplementedError(f"GraphicsFormat {self.m_Format} not supported yet")
+    assert self.object_reader is not None
 
     image_data = self.image_data
     if image_data is None:
+        assert self.m_StreamData is not None
         image_data = get_resource_data(
             self.m_StreamData.path,
             self.object_reader.assets_file,