add default draw target impl

src/render/draw_target/draw_target.rs

@@ -18,10 +18,12 @@ pub trait DrawTarget {
     );
     fn setup(
         &mut self,
-        world: &World,
-        resources: &Resources,
-        renderer: &mut dyn Renderer,
-        pipeline_handle: Handle<PipelineDescriptor>,
-    );
+        _world: &World,
+        _resources: &Resources,
+        _renderer: &mut dyn Renderer,
+        _pipeline_handle: Handle<PipelineDescriptor>,
+    ) {
+        
+    }
     fn get_name(&self) -> String;
 }

src/render/draw_target/draw_targets/meshes_draw_target.rs

@@ -58,15 +58,6 @@ impl DrawTarget for MeshesDrawTarget {
         }
     }
 
-    fn setup(
-        &mut self,
-        _world: &World,
-        _resources: &Resources,
-        _renderer: &mut dyn Renderer,
-        _pipeline_handle: Handle<PipelineDescriptor>,
-    ) {
-    }
-
     fn get_name(&self) -> String {
         resource_name::draw_target::MESHES.to_string()
     }