Pow3r: stage 1 (#4208)

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

Content.Server/NodeContainer/Nodes/NodeHelpers.cs

@@ -0,0 +1,89 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+
+namespace Content.Server.NodeContainer.Nodes
+{
+    /// <summary>
+    ///     Helper utilities for implementing <see cref="Node"/>.
+    /// </summary>
+    public static class NodeHelpers
+    {
+        public static IEnumerable<Node> GetNodesInTile(IComponentManager compMgr, IMapGrid grid, Vector2i coords)
+        {
+            foreach (var entityUid in grid.GetAnchoredEntities(coords))
+            {
+                if (!compMgr.TryGetComponent(entityUid, out NodeContainerComponent? container))
+                    continue;
+
+                foreach (var node in container.Nodes.Values)
+                {
+                    yield return node;
+                }
+            }
+        }
+
+        public static IEnumerable<(Direction dir, Node node)> GetCardinalNeighborNodes(
+            IComponentManager compMgr,
+            IMapGrid grid,
+            Vector2i coords,
+            bool includeSameTile = true)
+        {
+            foreach (var (dir, entityUid) in GetCardinalNeighborCells(grid, coords, includeSameTile))
+            {
+                if (!compMgr.TryGetComponent(entityUid, out NodeContainerComponent? container))
+                    continue;
+
+                foreach (var node in container.Nodes.Values)
+                {
+                    yield return (dir, node);
+                }
+            }
+        }
+
+        [SuppressMessage("ReSharper", "EnforceForeachStatementBraces")]
+        public static IEnumerable<(Direction dir, EntityUid entity)> GetCardinalNeighborCells(
+            IMapGrid grid,
+            Vector2i coords,
+            bool includeSameTile = true)
+        {
+            if (includeSameTile)
+            {
+                foreach (var uid in grid.GetAnchoredEntities(coords))
+                    yield return (Direction.Invalid, uid);
+            }
+
+            foreach (var uid in grid.GetAnchoredEntities(coords + (0, 1)))
+                yield return (Direction.North, uid);
+
+            foreach (var uid in grid.GetAnchoredEntities(coords + (0, -1)))
+                yield return (Direction.South, uid);
+
+            foreach (var uid in grid.GetAnchoredEntities(coords + (1, 0)))
+                yield return (Direction.East, uid);
+
+            foreach (var uid in grid.GetAnchoredEntities(coords + (-1, 0)))
+                yield return (Direction.West, uid);
+        }
+
+        public static Vector2i TileOffsetForDir(Direction dir)
+        {
+            return dir switch
+            {
+                Direction.Invalid => (0, 0),
+                Direction.South => (0, -1),
+                Direction.SouthEast => (1, -1),
+                Direction.East => (1, 0),
+                Direction.NorthEast => (1, 1),
+                Direction.North => (0, 1),
+                Direction.NorthWest => (-1, 1),
+                Direction.West => (-1, 0),
+                Direction.SouthWest => (-1, -1),
+                _ => throw new ArgumentOutOfRangeException(nameof(dir), dir, null)
+            };
+        }
+    }
+}