let
game_tick = 0,
game_time = 0.016,
game_real_time_last,
game_message_timeout = 0,

game_entities,
game_entities_enemies,
game_entities_friendly,
game_entity_player,
game_map_index,
game_jump_to_next_level,

game_init = (map_index) => {
	ts.style.display = 'none',

	game_entities = [];
	game_entities_enemies = [];
	game_entities_friendly = [];

	game_map_index = map_index;
	map_init(map_data[game_map_index]);
},

game_next_level = () => {
	game_jump_to_next_level = 1;
},

game_spawn = (type, pos, p1, p2) =>  {
	let entity = new (type)(pos, p1, p2)
	game_entities.push(entity);
	return entity;
},

game_show_message = (text) => {
	msg.textContent = text;
	msg.style.display = 'block';
	clearTimeout(game_message_timeout);
	game_message_timeout = setTimeout(()=>msg.style.display = 'none', 2000);
},

title_show_message = (msg, sub = '') => {
	ts.innerHTML = '<h1>'+msg+'</h1>' + sub;
	ts.style.display = 'block';
},

game_run = (time_now) => {
	requestAnimationFrame(game_run);

	time_now *= 0.001;
	game_tick = Math.min((time_now - (game_real_time_last||time_now)),0.05);
	game_real_time_last = time_now;
	game_time += game_tick;

	r_prepare_frame(0.1, 0.2, 0.5);

	// Update and render entities
	let alive_entities = [];
	for (let entity of game_entities) {
		if (!entity._dead) {
			entity._update();
			alive_entities.push(entity);
		}
	}
	game_entities = alive_entities;

	map_draw();
	r_end_frame();

	// Reset mouse movement and buttons that should be pressed, not held.
	mouse_x = mouse_y = 0;
	keys[key_next] = keys[key_prev] = 0;

	if (game_jump_to_next_level) {
		game_jump_to_next_level = 0;
		game_map_index++;
		if (game_map_index == 2) {
			title_show_message('THE END', 'THANKS FOR PLAYING ❤');
			h.textContent = a.textContent = '';
			game_entity_player._dead = 1;

			// Set camera position for end screen
			r_camera = vec3(1856,784,2272);
			r_camera_yaw = 0;
			r_camera_pitch = 0.5;
		}
		else {
			game_init(game_map_index);
		}
	}
};