seperate Stealth and StealthOnMove (#12035)

Content.Shared/Stealth/Components/StealthComponent.cs

@@ -5,8 +5,9 @@ using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom;
 namespace Content.Shared.Stealth.Components;
 /// <summary>
 /// Add this component to an entity that you want to be cloaked.
-/// It overlays a shader on the entity to give them an invisibility cloaked effect
+/// It overlays a shader on the entity to give them an invisibility cloaked effect.
-/// It also turns the entity invisible
+/// It also turns the entity invisible.
+/// Use other components (like StealthOnMove) to modify this component's visibility based on certain conditions.
 /// </summary>
 [RegisterComponent, NetworkedComponent]
 [Access(typeof(SharedStealthSystem))]
@@ -35,6 +36,7 @@ public sealed class StealthComponent : Component
     /// outside of this range simply act as a buffer for the visual effect (i.e., a delay before turning invisible). To
     /// get the actual current visibility, use <see cref="SharedStealthSystem.GetVisibility(EntityUid,
     /// StealthComponent?)"/>
+    /// If you don't have anything else updating the stealth, this will just stay at a constant value, which can be useful.
     /// </summary>
     [DataField("lastVisibility")]
     [Access(typeof(SharedStealthSystem),  Other = AccessPermissions.None)]
@@ -48,18 +50,6 @@ public sealed class StealthComponent : Component
     [DataField("lastUpdate", customTypeSerializer:typeof(TimeOffsetSerializer))]
     public TimeSpan? LastUpdated;
 
-    /// <summary>
-    /// Rate that effects how fast an entity's visibility passively changes.
-    /// </summary>
-    [DataField("passiveVisibilityRate")]
-    public readonly float PassiveVisibilityRate = -0.15f;
-
-    /// <summary>
-    /// Rate for movement induced visibility changes. Scales with distance moved.
-    /// </summary>
-    [DataField("movementVisibilityRate")]
-    public readonly float MovementVisibilityRate = 0.2f;
-
     /// <summary>
     /// Minimum visibility. Note that the visual effect caps out at -1, but this value is allowed to be larger or smaller.
     /// </summary>

Content.Shared/Stealth/Components/StealthOnMoveComponent.cs

@@ -0,0 +1,22 @@
+namespace Content.Shared.Stealth.Components
+{
+    /// <summary>
+    ///     When added to an entity with stealth component, this component will change the visibility
+    ///     based on the entity's (lack of) movement.
+    /// </summary>
+    [RegisterComponent]
+    public sealed class StealthOnMoveComponent : Component
+    {
+        /// <summary>
+        /// Rate that effects how fast an entity's visibility passively changes.
+        /// </summary>
+        [DataField("passiveVisibilityRate")]
+        public readonly float PassiveVisibilityRate = -0.15f;
+
+        /// <summary>
+        /// Rate for movement induced visibility changes. Scales with distance moved.
+        /// </summary>
+        [DataField("movementVisibilityRate")]
+        public readonly float MovementVisibilityRate = 0.2f;
+    }
+}

Content.Shared/Stealth/SharedStealthSystem.cs

@@ -15,7 +15,8 @@ public abstract class SharedStealthSystem : EntitySystem
 
         SubscribeLocalEvent<StealthComponent, ComponentGetState>(OnStealthGetState);
         SubscribeLocalEvent<StealthComponent, ComponentHandleState>(OnStealthHandleState);
-        SubscribeLocalEvent<StealthComponent, MoveEvent>(OnMove);
+        SubscribeLocalEvent<StealthOnMoveComponent, MoveEvent>(OnMove);
+        SubscribeLocalEvent<StealthOnMoveComponent, GetVisibilityModifiersEvent>(OnGetVisibilityModifiers);
         SubscribeLocalEvent<StealthComponent, EntityPausedEvent>(OnPaused);
         SubscribeLocalEvent<StealthComponent, ComponentInit>(OnInit);
         SubscribeLocalEvent<StealthComponent, ExamineAttemptEvent>(OnExamine);
@@ -87,7 +88,7 @@ public abstract class SharedStealthSystem : EntitySystem
         component.LastUpdated = cast.LastUpdated;
     }
 
-    private void OnMove(EntityUid uid, StealthComponent component, ref MoveEvent args)
+    private void OnMove(EntityUid uid, StealthOnMoveComponent component, ref MoveEvent args)
     {
         if (args.FromStateHandling)
             return;
@@ -96,7 +97,13 @@ public abstract class SharedStealthSystem : EntitySystem
             return;
 
         var delta = component.MovementVisibilityRate * (args.NewPosition.Position - args.OldPosition.Position).Length;
-        ModifyVisibility(uid, delta, component);
+        ModifyVisibility(uid, delta);
+    }
+
+    private void OnGetVisibilityModifiers(EntityUid uid, StealthOnMoveComponent component, GetVisibilityModifiersEvent args)
+    {
+        var mod = args.SecondsSinceUpdate * component.PassiveVisibilityRate;
+        args.FlatModifier += mod;
     }
 
     /// <summary>
@@ -150,6 +157,32 @@ public abstract class SharedStealthSystem : EntitySystem
             return component.LastVisibility;
 
         var deltaTime = _timing.CurTime - component.LastUpdated.Value;
-        return Math.Clamp(component.LastVisibility + (float) deltaTime.TotalSeconds * component.PassiveVisibilityRate, component.MinVisibility, component.MaxVisibility);
+
+        var ev = new GetVisibilityModifiersEvent(uid, component, (float) deltaTime.TotalSeconds, 0f);
+        RaiseLocalEvent(uid, ev, false);
+
+        return Math.Clamp(component.LastVisibility + ev.FlatModifier, component.MinVisibility, component.MaxVisibility);
+    }
+
+    /// <summary>
+    ///     Used to run through any stealth effecting components on the entity.
+    /// <summary>
+    private sealed class GetVisibilityModifiersEvent : EntityEventArgs
+    {
+        public readonly StealthComponent Stealth = default!;
+        public readonly float SecondsSinceUpdate;
+
+        /// <summary>
+        ///     Calculate this and add to it. Do not divide, multiply, or overwrite.
+        ///     The sum will be added to the stealth component's visibility.
+        /// </summary>
+        public float FlatModifier;
+
+        public GetVisibilityModifiersEvent(EntityUid uid, StealthComponent stealth, float secondsSinceUpdate, float flatModifier)
+        {
+            Stealth = stealth;
+            SecondsSinceUpdate = secondsSinceUpdate;
+            FlatModifier = flatModifier;
+        }
     }
 }

Resources/Prototypes/Entities/Structures/Storage/Closets/big_boxes.yml

@@ -68,6 +68,7 @@
           state: agentbox
           state_open: cardboard_open
     - type: Stealth
+    - type: StealthOnMove
       passiveVisibilityRate: -0.24
       movementVisibilityRate: 0.10
 
@@ -75,7 +76,7 @@
 - type: entity
   id: GhostBox
   parent: StealthBox
-  suffix: 
+  suffix:
   name: ghost box
   description: Beware!
   components: