UEFN-Tickable.verse

using. /Verse.org
using. /Verse.org/Native
using. /Verse.org/SceneGraph
using. /Verse.org/Simulation

tickable<public> := interface() {
    var Cancelable_PreTick<private>: ?cancelable = false;
    var Cancelable_PostTick<private>: ?cancelable = false;

    OnBeginSimulation<public>(Component: component):void =
        TickEvents := Component.GetTickEvents();
        set Cancelable_PreTick = option. TickEvents.PrePhysics.Subscribe(OnPreTick); # <- ignore error here
        set Cancelable_PostTick = option. TickEvents.PostPhysics.Subscribe(OnPostTick);  # <- ignore error here

    OnEndSimulation<public>(Component: component):void =
        if (Cancelable := Cancelable_PreTick?). Cancelable.Cancel();
        if (Cancelable := Cancelable_PostTick?). Cancelable.Cancel();
        set Cancelable_PreTick = false;
        set Cancelable_PostTick = false;

    OnPreTick<public>(Dt: float): void = {}
    OnPostTick<public>(Dt: float): void = {}
}

example usage:

test_component<public> := class<final_super>(component, tickable) {
    OnBeginSimulation<override>(): void = (tickable:)OnBeginSimulation(Self);
    OnEndSimulation<override>(): void = (tickable:)OnEndSimulation(Self);

    OnPreTick<override>(Dt: float): void = {
        # ...
    }
    
    OnPostTick<override>(Dt: float): void = {
        # ...
    }
}