Srushtika Neelakantam Srushtika

Srushtika / server.js

Created June 9, 2020 20:15

Code snippet 16 - For multiplayer space invaders article

	function startDownwardMovement(playerId) {
	let interval = setInterval(() => {
	if (players[playerId] && players[playerId].isAlive) {
	players[playerId].y += PLAYER_VERTICAL_INCREMENT;
	players[playerId].score += PLAYER_SCORE_INCREMENT;

	if (players[playerId].y > SHIP_PLATFORM) {
	finishGame(playerId);
	clearInterval(interval);
	}

Srushtika / server.js

Created June 9, 2020 17:13

Code snippet 15 - For multiplayer space invaders article

	function subscribeToPlayerInput(channelInstance, playerId) {
	channelInstance.subscribe("pos", (msg) => {
	if (msg.data.keyPressed == "left") {
	if (players[playerId].x - 20 < 20) {
	players[playerId].x = 20;
	} else {
	players[playerId].x -= 20;
	}
	} else if (msg.data.keyPressed == "right") {
	if (players[playerId].x + 20 > 1380) {

Srushtika / server.js

Created June 9, 2020 17:02

Code snippet 14 - For multiplayer space invaders article

	function startGameDataTicker() {
	let tickInterval = setInterval(() => {
	if (!gameTickerOn) {
	clearInterval(tickInterval);
	} else {
	bulletOrBlank = "";
	bulletTimer += GAME_TICKER_MS;
	if (bulletTimer >= GAME_TICKER_MS * 5) {
	bulletTimer = 0;
	bulletOrBlank = {

Srushtika / server.js

Last active June 9, 2020 20:34

Code snippet 19 - For multiplayer space invaders article

	function startShipAndBullets() {
	gameOn = true;

	world = new p2.World({
	gravity: [0, -9.82],
	});
	shipBody = new p2.Body({
	position: [shipX, shipY],
	velocity: [calcRandomVelocity(), 0],
	});

Srushtika / server.js

Last active June 9, 2020 20:25

Code snippet 13 - For multiplayer space invaders article

	function startGameDataTicker() {}

	function subscribeToPlayerInput(channelInstance, playerId) {}

	function startDownwardMovement(playerId) {}

	function finishGame(playerId) {}

	function resetServerState() {}

Srushtika / server.js

Created June 9, 2020 14:38

Code snippet 12 - For multiplayer space invaders article

	deadPlayerCh.subscribe("dead-notif", (msg) => {
	players[msg.data.deadPlayerId].isAlive = false;
	killerBulletId = msg.data.killerBulletId;
	alivePlayers--;
	if (alivePlayers == 0) {
	setTimeout(() => {
	finishGame("");
	}, 1000);
	}
	});

Srushtika / server.js

Created June 9, 2020 14:33

Code snippet 11 - For multiplayer space invaders article

	gameRoom.presence.subscribe("leave", (player) => {
	let leavingPlayer = player.clientId;
	alivePlayers--;
	totalPlayers--;
	delete players[leavingPlayer];
	if (totalPlayers <= 0) {
	resetServerState();
	}
	});

Srushtika / server.js

Created June 9, 2020 14:06

Code snippet 10 - For multiplayer space invaders article

	gameRoom.presence.subscribe("enter", (player) => {
	let newPlayerId;
	let newPlayerData;
	alivePlayers++;
	totalPlayers++;

	if (totalPlayers === 1) {
	gameTickerOn = true;
	startGameDataTicker();
	}

Srushtika / server.js

Last active June 9, 2020 13:53

Code snippet 9 - For multiplayer space invaders article


	realtime.connection.once("connected", () => {
	gameRoom = realtime.channels.get("game-room");
	deadPlayerCh = realtime.channels.get("dead-player");
	gameRoom.presence.subscribe("enter", (player) => {});
	gameRoom.presence.subscribe("leave", (player) => {});
	deadPlayerCh.subscribe("dead-notif", (msg) => {});
	});

Srushtika / server.js

Last active June 9, 2020 13:39

Code snippet 8 - For multiplayer space invaders article

	const realtime = Ably.Realtime({
	key: ABLY_API_KEY,
	echoMessages: false,
	});

	//create a uniqueId to assign to clients on auth
	const uniqueId = function () {
	return "id-" + totalPlayers + Math.random().toString(36).substr(2, 16);
	};