Fixed frame rate running in a specific state (or specify a state for a plugin)

[gak]

I've been searching around for this and couldn't find a solution.

I'm using states in my game and would like some systems to run on every frame and some on fixed frames (e.g. because of deterministic physics).

I've used the fixed timestep method from the examples (https://github.com/bevyengine/bevy/blob/latest/examples/ecs/fixed_timestep.rs) and have been trying to match it with SystemSets/states from (https://github.com/bevyengine/bevy/blob/latest/examples/ecs/state.rs) without any luck.

Is there a way I can get this going? This is a cut down version of one of my states as a plugin.

pub struct Game;

impl Plugin for Game {
    fn build(&self, app: &mut AppBuilder) {

        app.insert_resource(PathfindingMap::new())
            .add_system_set(
                SystemSet::on_enter(AppState::InGame)
                    .with_system(setup.system().label(Label::Setup)),
            )
            .add_system_set(
                SystemSet::on_update(AppState::InGame)
                    .with_system(ui.system())
                    .with_system(player::player_keyboard_action.system()),
            )
            .add_stage_after(
                CoreStage::Update,
                FixedUpdateStage,
                SystemStage::parallel()
                    .with_run_criteria(FixedTimestep::step(1f64 / 60f64))
                    // I'd like all of these to only run in AppState::InGame
                    .with_system(
                        player::player_keyboard_movement
                            .system()
                            .before(Label::CheckVelocityCollisions),
                    )
                    .with_system(player::chase_camera.system()),
            );
    }
}

Ideally I'd like the whole Plugin to run in a state to remove all references to AppState::InGame to make it easier to read and less prone to error.

[gak]

My dodgy solution is to check the state in each system.