From b459d2ce21799a3d43eb7373ac4701fb0adfafbb Mon Sep 17 00:00:00 2001
From: Leon Friedrich <60421075+ElectroJr@users.noreply.github.com>
Date: Wed, 22 Nov 2023 23:51:46 +1300
Subject: [PATCH] Add more map system helper methods. (#4589)

---
 .../Systems/SharedMapSystem.Grid.cs           | 33 +++++++++++++++++++
 .../GameObjects/Systems/SharedMapSystem.cs    |  1 +
 Robust.Shared/Map/ITileDefinitionManager.cs   |  1 +
 3 files changed, 35 insertions(+)

diff --git a/Robust.Shared/GameObjects/Systems/SharedMapSystem.Grid.cs b/Robust.Shared/GameObjects/Systems/SharedMapSystem.Grid.cs
index 9e81fb5864..c2ef2278a9 100644
--- a/Robust.Shared/GameObjects/Systems/SharedMapSystem.Grid.cs
+++ b/Robust.Shared/GameObjects/Systems/SharedMapSystem.Grid.cs
@@ -1292,6 +1292,9 @@ public abstract partial class SharedMapSystem
     }
 
     public Vector2i GridTileToChunkIndices(EntityUid uid, MapGridComponent grid, Vector2i gridTile)
+        => GridTileToChunkIndices(grid, gridTile);
+
+    public Vector2i GridTileToChunkIndices(MapGridComponent grid, Vector2i gridTile)
     {
         var x = (int)Math.Floor(gridTile.X / (float) grid.ChunkSize);
         var y = (int)Math.Floor(gridTile.Y / (float) grid.ChunkSize);
@@ -1334,6 +1337,36 @@ public abstract partial class SharedMapSystem
         return true;
     }
 
+    public bool TryGetTile(MapGridComponent grid, Vector2i indices, out Tile tile)
+    {
+        var chunkIndices = GridTileToChunkIndices(grid, indices);
+        if (!grid.Chunks.TryGetValue(chunkIndices, out var chunk))
+        {
+            tile = default;
+            return false;
+        }
+
+        var cTileIndices = chunk.GridTileToChunkTile(indices);
+        tile = chunk.Tiles[cTileIndices.X, cTileIndices.Y];
+        return true;
+    }
+
+    /// <summary>
+    /// Attempts to get the <see cref="ITileDefinition"/> for the tile at the given grid indices. This will throw an
+    /// exception if the tile at this location has no registered tile definition.
+    /// </summary>
+    public bool TryGetTileDef(MapGridComponent grid, Vector2i indices, [NotNullWhen(true)] out ITileDefinition? tileDef)
+    {
+        if (!TryGetTile(grid, indices, out var tile))
+        {
+            tileDef = null;
+            return false;
+        }
+
+        tileDef = _tileMan[tile.TypeId];
+        return true;
+    }
+
     public bool TryGetTileRef(EntityUid uid, MapGridComponent grid, EntityCoordinates coords, out TileRef tile)
     {
         return TryGetTileRef(uid, grid, CoordinatesToTile(uid, grid, coords), out tile);
diff --git a/Robust.Shared/GameObjects/Systems/SharedMapSystem.cs b/Robust.Shared/GameObjects/Systems/SharedMapSystem.cs
index 002235c59d..42f7feac44 100644
--- a/Robust.Shared/GameObjects/Systems/SharedMapSystem.cs
+++ b/Robust.Shared/GameObjects/Systems/SharedMapSystem.cs
@@ -12,6 +12,7 @@ namespace Robust.Shared.GameObjects
 {
     public abstract partial class SharedMapSystem : EntitySystem
     {
+        [Dependency] private readonly ITileDefinitionManager _tileMan = default!;
         [Dependency] private readonly IGameTiming _timing = default!;
         [Dependency] protected readonly IMapManager MapManager = default!;
         [Dependency] private readonly IMapManagerInternal _mapInternal = default!;
diff --git a/Robust.Shared/Map/ITileDefinitionManager.cs b/Robust.Shared/Map/ITileDefinitionManager.cs
index 08eff0bb80..4175350f5b 100644
--- a/Robust.Shared/Map/ITileDefinitionManager.cs
+++ b/Robust.Shared/Map/ITileDefinitionManager.cs
@@ -30,6 +30,7 @@ namespace Robust.Shared.Map
         /// <param name="id">The ID of the tile definition.</param>
         /// <returns>The tile definition.</returns>
         ITileDefinition this[int id] { get; }
+        // TODO add a try get and get-or-null variant.
 
         /// <summary>
         ///     The number of tile definitions contained inside of this manager.