NPC refactor (#10122)

Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>

Content.Server/NPC/Pathfinding/PathfindingSystem.cs

@@ -0,0 +1,78 @@
+using System.Threading;
+using Content.Server.CPUJob.JobQueues;
+using Content.Server.CPUJob.JobQueues.Queues;
+using Content.Server.NPC.Pathfinding.Pathfinders;
+using Content.Shared.Access.Systems;
+using Content.Shared.Physics;
+using Robust.Shared.Map;
+
+namespace Content.Server.NPC.Pathfinding
+{
+    /// <summary>
+    /// This system handles pathfinding graph updates as well as dispatches to the pathfinder
+    /// (90% of what it's doing is graph updates so not much point splitting the 2 roles)
+    /// </summary>
+    public sealed partial class PathfindingSystem : EntitySystem
+    {
+        [Dependency] private readonly AccessReaderSystem _access = default!;
+
+        private readonly PathfindingJobQueue _pathfindingQueue = new();
+
+        public const int TrackedCollisionLayers = (int)
+            (CollisionGroup.Impassable |
+             CollisionGroup.MidImpassable |
+             CollisionGroup.LowImpassable |
+             CollisionGroup.HighImpassable);
+
+        /// <summary>
+        /// Ask for the pathfinder to gimme somethin
+        /// </summary>
+        public Job<Queue<TileRef>> RequestPath(PathfindingArgs pathfindingArgs, CancellationToken cancellationToken)
+        {
+            var startNode = GetNode(pathfindingArgs.Start);
+            var endNode = GetNode(pathfindingArgs.End);
+            var job = new AStarPathfindingJob(0.001, startNode, endNode, pathfindingArgs, cancellationToken, EntityManager);
+            _pathfindingQueue.EnqueueJob(job);
+
+            return job;
+        }
+
+        public Job<Queue<TileRef>> RequestPath(EntityUid source, EntityUid target, CancellationToken cancellationToken)
+        {
+            var collisionMask = 0;
+
+            if (TryComp<PhysicsComponent>(source, out var body))
+            {
+                collisionMask = body.CollisionMask;
+            }
+
+            var start = TileRef.Zero;
+            var end = TileRef.Zero;
+
+            if (TryComp<TransformComponent>(source, out var xform) &&
+                _mapManager.TryGetGrid(xform.GridUid, out var grid) &&
+                TryComp<TransformComponent>(target, out var targetXform) &&
+                _mapManager.TryGetGrid(targetXform.GridUid, out var targetGrid))
+            {
+                start = grid.GetTileRef(xform.Coordinates);
+                end = grid.GetTileRef(targetXform.Coordinates);
+            }
+
+            var args = new PathfindingArgs(source, _access.FindAccessTags(source), collisionMask, start, end);
+
+            var startNode = GetNode(start);
+            var endNode = GetNode(end);
+            var job = new AStarPathfindingJob(0.001, startNode, endNode, args, cancellationToken, EntityManager);
+            _pathfindingQueue.EnqueueJob(job);
+
+            return job;
+        }
+
+        public override void Update(float frameTime)
+        {
+            base.Update(frameTime);
+            ProcessGridUpdates();
+            _pathfindingQueue.Process();
+        }
+    }
+}