fix camera matrix hacks

src/game/Level.h

@@ -11,7 +11,11 @@
     struct X                                                                                                           \
     {                                                                                                                  \
         uint16_t Idx = UINT16_MAX;                                                                                     \
-    };
+    };                                                                                                                 \
+    inline bool IsValid(X h)                                                                                           \
+    {                                                                                                                  \
+        return h.Idx != UINT16_MAX;                                                                                    \
+    }
 
 namespace Game
 {
@@ -149,6 +153,7 @@ namespace Game
         EntityManager<TestEntity, TestEntityHandle, 32> Tests;
         EntityManager<PuzzleTileEntity, PuzzleTileEntityHandle, 1024> PuzzleTiles;
         EntityManager<UIQuadEntity, UIQuadEntityHandle, 1024> UIQuads;
+        CubeHandle PlayerOutsideViewCube;
 
       public:
         Generated::StaticPuzzleData PuzzleData;