Reduce knocked down players tile friction (#11035)

2022-09-11 16:49:10 +10:00
parent 47dd0ff2e8
commit 12e1a961d6
12 changed files with 80 additions and 124 deletions
--- a/Content.Shared/Slippery/SlipperySystem.cs
+++ b/Content.Shared/Slippery/SlipperySystem.cs
@@ -0,0 +1,107 @@
+using Content.Shared.Administration.Logs;
+using Content.Shared.Database;
+using Content.Shared.Inventory;
+using Content.Shared.StatusEffect;
+using Content.Shared.StepTrigger.Systems;
+using Content.Shared.Stunnable;
+using JetBrains.Annotations;
+using Robust.Shared.Audio;
+using Robust.Shared.Containers;
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Slippery
+{
+    [UsedImplicitly]
+    public sealed class SlipperySystem : EntitySystem
+    {
+        [Dependency] private readonly ISharedAdminLogManager _adminLogger = default!;
+        [Dependency] private readonly SharedAudioSystem _audio = default!;
+        [Dependency] private readonly SharedStunSystem _stunSystem = default!;
+        [Dependency] private readonly StatusEffectsSystem _statusEffectsSystem = default!;
+        [Dependency] private readonly SharedContainerSystem _container = default!;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<SlipperyComponent, StepTriggerAttemptEvent>(HandleAttemptCollide);
+            SubscribeLocalEvent<SlipperyComponent, StepTriggeredEvent>(HandleStepTrigger);
+            SubscribeLocalEvent<NoSlipComponent, SlipAttemptEvent>(OnNoSlipAttempt);
+            SubscribeLocalEvent<SlipperyComponent, ComponentGetState>(OnSlipperyGetState);
+            SubscribeLocalEvent<SlipperyComponent, ComponentHandleState>(OnSlipperyHandleState);
+        }
+
+        private void OnSlipperyHandleState(EntityUid uid, SlipperyComponent component, ref ComponentHandleState args)
+        {
+            if (args.Current is not SlipperyComponentState state) return;
+
+            component.ParalyzeTime = state.ParalyzeTime;
+            component.LaunchForwardsMultiplier = state.LaunchForwardsMultiplier;
+            component.SlipSound = new SoundPathSpecifier(state.SlipSound);
+        }
+
+        private void OnSlipperyGetState(EntityUid uid, SlipperyComponent component, ref ComponentGetState args)
+        {
+            args.State = new SlipperyComponentState(component.ParalyzeTime, component.LaunchForwardsMultiplier, component.SlipSound.GetSound());
+        }
+
+        private void HandleStepTrigger(EntityUid uid, SlipperyComponent component, ref StepTriggeredEvent args)
+        {
+            TrySlip(component, args.Tripper);
+        }
+
+        private void HandleAttemptCollide(
+            EntityUid uid,
+            SlipperyComponent component,
+            ref StepTriggerAttemptEvent args)
+        {
+            args.Continue |= CanSlip(uid, args.Tripper);
+        }
+
+        private static void OnNoSlipAttempt(EntityUid uid, NoSlipComponent component, SlipAttemptEvent args)
+        {
+            args.Cancel();
+        }
+
+        private bool CanSlip(EntityUid uid, EntityUid toSlip)
+        {
+            return !_container.IsEntityInContainer(uid)
+                   && _statusEffectsSystem.CanApplyEffect(toSlip, "Stun"); //Should be KnockedDown instead?
+        }
+
+        private void TrySlip(SlipperyComponent component, EntityUid other)
+        {
+            if (HasComp<KnockedDownComponent>(other))
+                return;
+
+            var ev = new SlipAttemptEvent();
+            RaiseLocalEvent(other, ev, false);
+            if (ev.Cancelled)
+                return;
+
+            if (TryComp(other, out PhysicsComponent? physics))
+                physics.LinearVelocity *= component.LaunchForwardsMultiplier;
+
+            var playSound = !_statusEffectsSystem.HasStatusEffect(other, "KnockedDown");
+
+            _stunSystem.TryParalyze(other, TimeSpan.FromSeconds(component.ParalyzeTime), true);
+
+            // Preventing from playing the slip sound when you are already knocked down.
+            if (playSound)
+            {
+                _audio.PlayPredicted(component.SlipSound, other, other);
+            }
+
+            _adminLogger.Add(LogType.Slip, LogImpact.Low,
+                $"{ToPrettyString(other):mob} slipped on collision with {ToPrettyString(component.Owner):entity}");
+        }
+    }
+
+    /// <summary>
+    ///     Raised on an entity to determine if it can slip or not.
+    /// </summary>
+    public sealed class SlipAttemptEvent : CancellableEntityEventArgs, IInventoryRelayEvent
+    {
+        public SlotFlags TargetSlots { get; } = SlotFlags.FEET;
+    }
+}