add syndicate singularity beacon (#18486)

* implement singulo attraction

* add attractor syndie item

* cleanup

* fix name/desc

* actually fix name

* singulo toolbox no longer whitelisted

* add custom sprite, overhaul prototype

* address review

* beacon real

* webedit 1

* webedit 2

* webedit 3

* permalink to copyright

---------

Co-authored-by: deltanedas <39013340+deltanedas@users.noreply.github.com>

Content.Server/Singularity/Components/SingularityAttractorComponent.cs

@@ -0,0 +1,30 @@
+using Content.Server.Singularity.EntitySystems;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom;
+
+namespace Content.Server.Singularity.Components;
+
+/// <summary>
+/// Attracts the singularity.
+/// </summary>
+[RegisterComponent]
+[Access(typeof(SingularityAttractorSystem))]
+public sealed partial class SingularityAttractorComponent : Component
+{
+    /// <summary>
+    /// The range at which singularities will be unable to go away from the attractor.
+    /// </summary>
+    [DataField, ViewVariables(VVAccess.ReadWrite)]
+    public float BaseRange = 25f;
+
+    /// <summary>
+    /// The amount of time that should elapse between pulses of this attractor.
+    /// </summary>
+    [DataField, ViewVariables(VVAccess.ReadOnly)]
+    public TimeSpan TargetPulsePeriod = TimeSpan.FromSeconds(2);
+
+    /// <summary>
+    /// The last time this attractor pulsed.
+    /// </summary>
+    [DataField(customTypeSerializer: typeof(TimeOffsetSerializer))]
+    public TimeSpan LastPulseTime = default!;
+}

Content.Server/Singularity/EntitySystems/SingularityAttractorSystem.cs

@@ -0,0 +1,106 @@
+using Content.Server.Physics.Components;
+using Content.Server.Power.EntitySystems;
+using Content.Server.Singularity.Components;
+using Content.Shared.Singularity.Components;
+using Content.Shared.Singularity.EntitySystems;
+using Robust.Shared.Map;
+using Robust.Shared.Map.Components;
+using Robust.Shared.Physics;
+using Robust.Shared.Physics.Components;
+using Robust.Shared.Physics.Systems;
+using Robust.Shared.Timing;
+using System.Numerics;
+
+namespace Content.Server.Singularity.EntitySystems;
+
+/// <summary>
+/// Handles singularity attractors.
+/// </summary>
+public sealed class SingularityAttractorSystem : EntitySystem
+{
+    [Dependency] private readonly EntityLookupSystem _lookup = default!;
+    [Dependency] private readonly IGameTiming _timing = default!;
+
+    /// <summary>
+    /// The minimum range at which the attraction will act.
+    /// Prevents division by zero problems.
+    /// </summary>
+    public const float MinAttractRange = 0.00001f;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<SingularityAttractorComponent, MapInitEvent>(OnMapInit);
+    }
+
+    /// <summary>
+    /// Updates the pulse cooldowns of all singularity attractors.
+    /// If they are off cooldown it makes them emit an attraction pulse and reset their cooldown.
+    /// </summary>
+    /// <param name="frameTime">The time elapsed since the last set of updates.</param>
+    public override void Update(float frameTime)
+    {
+        if (!_timing.IsFirstTimePredicted)
+            return;
+
+        var query = EntityQueryEnumerator<SingularityAttractorComponent, TransformComponent>();
+        var now = _timing.CurTime;
+        while (query.MoveNext(out var uid, out var attractor, out var xform))
+        {
+            if (attractor.LastPulseTime + attractor.TargetPulsePeriod <= now)
+                Update(uid, attractor, xform);
+        }
+    }
+
+    /// <summary>
+    /// Makes an attractor attract all singularities and puts it on cooldown.
+    /// </summary>
+    /// <param name="uid">The uid of the attractor to make pulse.</param>
+    /// <param name="attractor">The state of the attractor to make pulse.</param>
+    /// <param name="xform">The transform of the attractor to make pulse.</param>
+    private void Update(EntityUid uid, SingularityAttractorComponent? attractor = null, TransformComponent? xform = null)
+    {
+        if (!Resolve(uid, ref attractor, ref xform))
+            return;
+
+        if (!this.IsPowered(uid, EntityManager))
+            return;
+
+        attractor.LastPulseTime = _timing.CurTime;
+
+        var mapPos = xform.Coordinates.ToMap(EntityManager);
+
+        if (mapPos == MapCoordinates.Nullspace)
+            return;
+
+        var query = EntityQuery<SingularityComponent, RandomWalkComponent, TransformComponent>();
+        foreach (var (singulo, walk, singuloXform) in query)
+        {
+            var singuloMapPos = singuloXform.Coordinates.ToMap(EntityManager);
+
+            if (singuloMapPos.MapId != mapPos.MapId)
+                continue;
+
+            var biasBy = mapPos.Position - singuloMapPos.Position;
+            var length = biasBy.Length();
+            if (length <= MinAttractRange)
+                return;
+
+            biasBy = Vector2.Normalize(biasBy) * (attractor.BaseRange / length);
+
+            walk.BiasVector += biasBy;
+        }
+    }
+
+    /// <summary>
+    /// Resets the pulse timings of the attractor when the component starts up.
+    /// </summary>
+    /// <param name="uid">The uid of the attractor to start up.</param>
+    /// <param name="comp">The state of the attractor to start up.</param>
+    /// <param name="args">The startup prompt arguments.</param>
+    private void OnMapInit(Entity<SingularityAttractorComponent> ent, ref MapInitEvent args)
+    {
+        ent.Comp.LastPulseTime = _timing.CurTime;
+    }
+}