// TODO: center background if screen bigger
SDL_BlitSurface(background, 0, screen, 0);
for (vector<Monster>::size_type i(0), end(monsters.size()); i < end; ++i) {
// TODO: center background if screen bigger
SDL_BlitSurface(background, 0, screen, 0);
for (vector<Monster>::size_type i(0), end(monsters.size()); i < end; ++i) {