Add sun shadows (planet lighting stage 2) (#35145)

* Implements a Dynamic Lighting System on maps.

* Edit: the night should be a little bit brighter and blue now.

* Major edit: everything must be done on the client side now, with certain datafield replicated.
Changes were outlined in the salvage to accommodate the new lighting system.

* Edit: The offset is now serverside, this makes the time accurate in all situations.

* Removing ununsed import

* Minor tweaks

* Tweak in time precision

* Minor tweak + Unused import removed

* Edit: apparently RealTime is better for what I'm looking for

* Fix: Now the time is calculated correctly.

* Minor tweaks

* Adds condition for when the light should be updated

* Add planet lighting

* she

* close-ish

* c

* bittersweat

* Fixes

* Revert "Merge branch '22719' into 2024-09-29-planet-lighting"

This reverts commit 9f2785bb16aee47d794aa3eed8ae15004f97fc35, reversing
changes made to 19649c07a5fb625423e08fc18d91c9cb101daa86.

* Europa and day-night

* weh

* rooves working

* Clean

* Remove Europa

* Fixes

* fix

* Update

* Fix caves

* Update for engine

* Add sun shadows (planet lighting v2)

For now mostly targeting walls and having the shadows change over time. Got the basic proof-of-concept working just needs a hell of a lot of polish.

* Documentation

* a

* Fixes

* Move blur to an overlay

* Slughands

* Fixes

* Apply RoofOverlay per-grid not per-map

* Fix light render scales

* sangas

* Juice it a bit

* Better angle

* Fixes

* Add color support

* Rounding bandaid

* Wehs

* Better

* Remember I forgot to do this when writing docs

---------

Co-authored-by: DoutorWhite <thedoctorwhite@gmail.com>

Content.Shared/Light/EntitySystems/SharedRoofSystem.cs

@@ -1,3 +1,4 @@
+using System.Diagnostics.Contracts;
 using Content.Shared.Light.Components;
 using Content.Shared.Maps;
 using Robust.Shared.Map;
@@ -18,6 +19,7 @@ public abstract class SharedRoofSystem : EntitySystem
     /// Returns whether the specified tile is roof-occupied.
     /// </summary>
     /// <returns>Returns false if no data or not rooved.</returns>
+    [Pure]
     public bool IsRooved(Entity<MapGridComponent, RoofComponent> grid, Vector2i index)
     {
         var roof = grid.Comp2;
@@ -49,6 +51,40 @@ public abstract class SharedRoofSystem : EntitySystem
         return false;
     }
 
+    [Pure]
+    public Color? GetColor(Entity<MapGridComponent, RoofComponent> grid, Vector2i index)
+    {
+        var roof = grid.Comp2;
+        var chunkOrigin = SharedMapSystem.GetChunkIndices(index, RoofComponent.ChunkSize);
+
+        if (roof.Data.TryGetValue(chunkOrigin, out var bitMask))
+        {
+            var chunkRelative = SharedMapSystem.GetChunkRelative(index, RoofComponent.ChunkSize);
+            var bitFlag = (ulong) 1 << (chunkRelative.X + chunkRelative.Y * RoofComponent.ChunkSize);
+
+            var isRoof = (bitMask & bitFlag) == bitFlag;
+
+            // Early out, otherwise check for components on tile.
+            if (isRoof)
+            {
+                return roof.Color;
+            }
+        }
+
+        _roofSet.Clear();
+        _lookup.GetLocalEntitiesIntersecting(grid.Owner, index, _roofSet);
+
+        foreach (var isRoofEnt in _roofSet)
+        {
+            if (!isRoofEnt.Comp.Enabled)
+                continue;
+
+            return isRoofEnt.Comp.Color ?? roof.Color;
+        }
+
+        return null;
+    }
+
     public void SetRoof(Entity<MapGridComponent?, RoofComponent?> grid, Vector2i index, bool value)
     {
         if (!Resolve(grid, ref grid.Comp1, ref grid.Comp2, false))