Add TODO notes for tile lighting stuff coming soon.

Core/include/Core/Tile.hpp

@@ -32,6 +32,26 @@ namespace CaveGame::Core {
 
     static std::map<std::string, TileTiccFunc> ticc_funcs;
 
+    // TODO: Tile light filling algorithm.
+    // TODO: Ambient light from surface / certain biomes.
+    // TODO: Directional lights.
+    // TODO: Entity lights.
+    // TODO: Tinting when interact with certain tiles.
+    // TODO: Research recursive flood-fill algorithm.
+
+    struct light {
+        uint8_t r;
+        uint8_t g;
+        uint8_t b;
+        uint8_t intensity;
+
+    };
+
+    // TODO: Implement params for tile color interaction
+    // * Opacity
+    // * Illumination
+    // * What if we want to make tiles reactive, glow under UV, absorb light energy?
+
     struct Tile {
         std::string mnemonic_id;
         std::string display_name;
@@ -47,6 +67,9 @@ namespace CaveGame::Core {
         TileTiccFunc random_ticc_func;
         std::vector<std::string> tags;
         bool gravity;
+        bool opaque = true;
+        std::optional<Color3> illumination;
+
     };
     /*
      *