Process -> Audio; Layers2 -> Layers

crates/tek_core/src/engine.rs

@@ -25,6 +25,10 @@ pub trait Engine: Send + Sync + Sized {
     // FIXME
     fn with_area (&mut self, x: Self::Unit, y: Self::Unit, w: Self::Unit, h: Self::Unit)
         -> &mut Self;
+    // FIXME
+    fn render_in (
+        &mut self, area: Self::Area, widget: &impl Widget<Engine = Self>
+    ) -> Perhaps<Self::Area>;
 }
 
 submod! {