Remove pathfinding graph node directions (#1223)

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

Content.IntegrationTests/Tests/Pathfinding/PathfindingChunkTest.cs

@@ -0,0 +1,65 @@
+using System.Linq;
+using System.Threading.Tasks;
+using Content.Server.GameObjects.EntitySystems.AI.Pathfinding;
+using NUnit.Framework;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Interfaces.Map;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+
+namespace Content.IntegrationTests.Tests.Pathfinding
+{
+    [TestFixture]
+    [TestOf(typeof(PathfindingChunk))]
+    public class PathfindingChunkTest : ContentIntegrationTest
+    {
+        [Test]
+        public async Task Test()
+        {
+            var server = StartServerDummyTicker();
+            
+            server.Assert(() =>
+            {
+                var pathfindingSystem = EntitySystem.Get<PathfindingSystem>();
+                var mapMan = IoCManager.Resolve<IMapManager>();
+
+                // Setup
+                var mapId = mapMan.CreateMap(new MapId(1));
+                var gridId = new GridId(2);
+                mapMan.CreateGrid(mapId, gridId);
+                var chunkTile = mapMan.GetGrid(gridId).GetTileRef(new MapIndices(0, 0));
+                var chunk = pathfindingSystem.GetChunk(chunkTile);
+                Assert.That(chunk.Nodes.Length == PathfindingChunk.ChunkSize * PathfindingChunk.ChunkSize);
+                
+                // Neighbors
+                var chunkNeighbors = chunk.GetNeighbors().ToList();
+                Assert.That(chunkNeighbors.Count == 0);
+                var neighborChunkTile = mapMan.GetGrid(gridId).GetTileRef(new MapIndices(PathfindingChunk.ChunkSize, PathfindingChunk.ChunkSize));
+                var neighborChunk = pathfindingSystem.GetChunk(neighborChunkTile);
+                chunkNeighbors = chunk.GetNeighbors().ToList();
+                Assert.That(chunkNeighbors.Count == 1);
+                
+                // Directions
+                Assert.That(PathfindingHelpers.RelativeDirection(neighborChunk, chunk) == Direction.NorthEast);
+                Assert.That(PathfindingHelpers.RelativeDirection(chunk.Nodes[0, 1], chunk.Nodes[0, 0]) == Direction.North);
+                
+                // Nodes
+                var node = chunk.Nodes[1, 1];
+                var nodeNeighbors = node.GetNeighbors().ToList();
+                Assert.That(nodeNeighbors.Count == 8);
+                
+                // Bottom-left corner with no chunk neighbor
+                node = chunk.Nodes[0, 0];
+                nodeNeighbors = node.GetNeighbors().ToList();
+                Assert.That(nodeNeighbors.Count == 3);
+                
+                // Given we have 1 NE neighbor then NE corner should have 4 neighbors due to the 1 extra from the neighbor chunk
+                node = chunk.Nodes[PathfindingChunk.ChunkSize - 1, PathfindingChunk.ChunkSize - 1];
+                nodeNeighbors = node.GetNeighbors().ToList();
+                Assert.That(nodeNeighbors.Count == 4);
+            });
+            await server.WaitIdleAsync();
+        }
+    }
+}