NPC refactor (#10122)

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

Content.Client/NPC/HTN/HTNOverlay.cs

@@ -0,0 +1,41 @@
+using Robust.Client.Graphics;
+using Robust.Client.ResourceManagement;
+using Robust.Shared.Enums;
+
+namespace Content.Client.NPC.HTN;
+
+public sealed class HTNOverlay : Overlay
+{
+    private readonly IEntityManager _entManager = default!;
+    private readonly Font _font = default!;
+
+    public override OverlaySpace Space => OverlaySpace.ScreenSpace;
+
+    public HTNOverlay(IEntityManager entManager, IResourceCache resourceCache)
+    {
+        _entManager = entManager;
+        _font = new VectorFont(resourceCache.GetResource<FontResource>("/Fonts/NotoSans/NotoSans-Regular.ttf"), 10);
+    }
+
+    protected override void Draw(in OverlayDrawArgs args)
+    {
+        if (args.ViewportControl == null)
+            return;
+
+        var handle = args.ScreenHandle;
+
+        foreach (var (comp, xform) in _entManager.EntityQuery<HTNComponent, TransformComponent>(true))
+        {
+            if (string.IsNullOrEmpty(comp.DebugText) || xform.MapID != args.MapId)
+                continue;
+
+            var worldPos = xform.WorldPosition;
+
+            if (!args.WorldAABB.Contains(worldPos))
+                continue;
+
+            var screenPos = args.ViewportControl.WorldToScreen(worldPos);
+            handle.DrawString(_font, screenPos + new Vector2(0, 10f), comp.DebugText);
+        }
+    }
+}