start screen refactor

src/screen.hpp

@@ -2,14 +2,21 @@
 
 #include <SDL3/SDL.h>
 
+// all time values are in seconds
 struct Screen {
 	virtual ~Screen(void) = default;
 
 	// return true if handled
-	virtual bool handleEvent(SDL_Event& e) { return false; }
+	virtual bool handleEvent(SDL_Event&) { return false; }
 
 	// return nullptr if not next
 	// sets bool quit to true if exit
-	virtual Screen* poll(bool& quit) = 0;
+	// both render and tick get called in the selfreported intervals
+	virtual Screen* render(float time_delta, bool& quit) = 0; // pure since this is a graphical app
+	virtual Screen* tick(float time_delta, bool& quit) = 0;
+
+	// TODO: const?
+	virtual float nextRender(void) { return 1.f/60.f; }
+	virtual float nextTick(void) { return 0.03f; }
 };