Delta-v/Content.Server/NodeContainer/Nodes/AdjacentNode.cs

using Content.Shared.NodeContainer;
using Robust.Shared.Map.Components;

namespace Content.Server.NodeContainer.Nodes
{
    /// <summary>
    ///     A <see cref="Node"/> that can reach other <see cref="AdjacentNode"/>s that are directly adjacent to it.
    /// </summary>
    [DataDefinition]
    public sealed partial class AdjacentNode : Node
    {
        public override IEnumerable<Node> GetReachableNodes(
            Entity<TransformComponent> xform,
            EntityQuery<NodeContainerComponent> nodeQuery,
            EntityQuery<TransformComponent> xformQuery,
            Entity<MapGridComponent>? grid,
            IEntityManager entMan)
        {
            if (!xform.Comp.Anchored || grid is not { } gridEnt)
                yield break;

            var mapSystem = entMan.System<SharedMapSystem>();
            var gridIndex = mapSystem.TileIndicesFor(gridEnt, xform.Comp.Coordinates);

            foreach (var (_, node) in NodeHelpers.GetCardinalNeighborNodes(nodeQuery, gridEnt, gridIndex, mapSystem))
            {
                if (node != this)
                    yield return node;
            }
        }
    }
}