Fixing screen resize bugs

src/Game.h

@@ -39,6 +39,7 @@ namespace FRG {
 		void setupPart2();
 		void update();
 		void render();
+		void onWindowResized();
 
 		bool shouldExit() const { return Environment::exitGameLoop; }
 
@@ -201,6 +202,9 @@ namespace FRG {
 		int64_t newTickCount;
 		int64_t lastTickCount;
 
+		int lastDrawableW = -1;
+		int lastDrawableH = -1;
+
 		static const size_t CONST_TIMER_INTERVAL = 10;
 		static const size_t CONST_MAX_TIME_INTERVAL = 1000;
 	};