/// run until user quits
void Run();
+ /// evaluate a single frame of dt milliseconds
void Loop(int dt);
/// run for n frames
/// run for n frames, assuming t milliseconds for each
void RunS(size_t n, size_t t);
+ /// process all events in SDL's queue
void HandleEvents();
+ /// integrate to the next step with dt milliseconds passed
void Update(int dt);
+ /// push the current state to display
void Render();
static Entity &MakeTestEntity(World &);