internal: FFIView getRenderTarget

thermion_dart/lib/src/viewer/src/shared_types/view.dart

@@ -17,6 +17,7 @@ class Viewport {
 abstract class View {
   Future<Viewport> getViewport();
   Future updateViewport(int width, int height);
+  Future<RenderTarget?> getRenderTarget();
   Future setRenderTarget(covariant RenderTarget? renderTarget);
   Future setCamera(covariant Camera camera);
   Future<Camera> getCamera();