Pow3r: stage 1 (#4208)

Co-authored-by: 20kdc <asdd2808@gmail.com>

Content.Server/Power/EntitySystems/CableVisSystem.cs

@@ -0,0 +1,85 @@
+using System.Collections.Generic;
+using Content.Server.NodeContainer;
+using Content.Server.NodeContainer.EntitySystems;
+using Content.Server.Power.Components;
+using Content.Server.Power.Nodes;
+using Content.Shared.Wires;
+using JetBrains.Annotations;
+using Robust.Server.GameObjects;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+
+namespace Content.Server.Power.EntitySystems
+{
+    [UsedImplicitly]
+    public sealed class CableVisSystem : EntitySystem
+    {
+        [Dependency] private readonly IMapManager _mapManager = default!;
+
+        private readonly HashSet<EntityUid> _toUpdate = new();
+
+        public void QueueUpdate(EntityUid uid)
+        {
+            _toUpdate.Add(uid);
+        }
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            UpdatesAfter.Add(typeof(NodeGroupSystem));
+        }
+
+        public override void Update(float frameTime)
+        {
+            base.Update(frameTime);
+
+            foreach (var uid in _toUpdate)
+            {
+                if (!ComponentManager.TryGetComponent(uid, out NodeContainerComponent? nodeContainer)
+                    || !ComponentManager.TryGetComponent(uid, out CableVisComponent? cableVis)
+                    || !ComponentManager.TryGetComponent(uid, out AppearanceComponent? appearance))
+                {
+                    continue;
+                }
+
+                if (cableVis.Node == null)
+                    continue;
+
+                var mask = WireVisDirFlags.None;
+
+                var transform = ComponentManager.GetComponent<ITransformComponent>(uid);
+                var grid = _mapManager.GetGrid(transform.GridID);
+                var tile = grid.TileIndicesFor(transform.Coordinates);
+                var node = nodeContainer.GetNode<CableNode>(cableVis.Node);
+
+                foreach (var reachable in node.ReachableNodes)
+                {
+                    if (reachable is not CableNode)
+                        continue;
+
+                    var otherTransform = reachable.Owner.Transform;
+                    if (otherTransform.GridID != grid.Index)
+                        continue;
+
+                    var otherTile = grid.TileIndicesFor(otherTransform.Coordinates);
+                    var diff = otherTile - tile;
+
+                    mask |= diff switch
+                    {
+                        (0, 1) => WireVisDirFlags.North,
+                        (0, -1) => WireVisDirFlags.South,
+                        (1, 0) => WireVisDirFlags.East,
+                        (-1, 0) => WireVisDirFlags.West,
+                        _ => WireVisDirFlags.None
+                    };
+                }
+
+                appearance.SetData(WireVisVisuals.ConnectedMask, mask);
+            }
+
+            _toUpdate.Clear();
+        }
+    }
+}