fn init(&mut self, _app_context: &mut AppContext)
fn on_event(&mut self, _event: &Event<'_, ()>, _app_context: &mut AppContext)
fn on_fixed_update(&mut self, _app_context: &mut AppContext)
fn on_frame_update(&mut self, _app_context: &mut AppContext)
fn on_imgui_update(&mut self, _ui: &Ui<'_>, _app_context: &mut AppContext)