CatStation/Content.Shared/Movement/Systems/MovementSoundSystem.cs

using Content.Shared.Movement.Components;
using Content.Shared.Movement.Events;
using Robust.Shared.Audio.Systems;
using Robust.Shared.Timing;
using Robust.Shared.Utility;

namespace Content.Shared.Movement.Systems;

/// <summary>
/// Plays a sound on MoveInputEvent.
/// </summary>
public sealed partial class MovementSoundSystem : EntitySystem
{
    [Dependency] private IGameTiming _timing = default!;
    [Dependency] private SharedAudioSystem _audio = default!;

    public override void Initialize()
    {
        base.Initialize();
        SubscribeLocalEvent<MovementSoundComponent, MoveInputEvent>(OnMoveInput);
    }

    private void OnMoveInput(Entity<MovementSoundComponent> ent, ref MoveInputEvent args)
    {
        if (!_timing.IsFirstTimePredicted)
            return;

        var oldMoving = (SharedMoverController.GetNormalizedMovement(args.OldMovement) & MoveButtons.AnyDirection) != MoveButtons.None;
        var moving = (SharedMoverController.GetNormalizedMovement(args.Entity.Comp.HeldMoveButtons) & MoveButtons.AnyDirection) != MoveButtons.None;

        if (oldMoving == moving)
            return;

        if (moving)
        {
            DebugTools.Assert(ent.Comp.SoundEntity == null);
            ent.Comp.SoundEntity = _audio.PlayPredicted(ent.Comp.Sound, ent.Owner, ent.Owner)?.Entity;
        }
        else
        {
            ent.Comp.SoundEntity = _audio.Stop(ent.Comp.SoundEntity);
        }
    }
}