Talking about Don't touch the spikes game, Game development, HTML5, Javascript and Phaser.
This 4th part of the “Don’t Touch the Spikes” HTML5 prototype built with Phaser and Matter physics will add coins to collect.
Let’s make a small recap: in the first step we saw how to bind Matter physics to Phaser images, in step 2 we created a completely playable game just rendered in debug draw, then graphic assets were added again in step 3.
Now it’s time to add a coin the player has to collect, this way:
Tap or click to jump, touch a spike and it’s game over. Collect coins to… well for the sake of collecting coins at the moment.
Coins introduce a new kind of Matter body called sensor. Sensors trigger collision events, but do not react with colliding body physically, so the player won’t bounce on the coin, and it’s exactly what we need.
Have a look at the source code, still uncommented with the new lines highlighted:
var game;
var gameOptions = {
triangleBase: 60,
ballSpeed: 7,
jumpForce: 10
}
window.onload = function() {
var gameConfig = {
type: Phaser.AUTO,
width: gameOptions.triangleBase * 9.5,
height: gameOptions.triangleBase * 15.5,
backgroundColor: 0x000000,
scene: playGame,
physics: {
default: "matter",
matter: {
debug: true
}
}
}
game = new Phaser.Game(gameConfig);
window.focus();
resize();
window.addEventListener("resize", resize, false);
}
class playGame extends Phaser.Scene{
constructor(){
super("PlayGame");
}
preload(){
this.load.image("spike", "spike.png");
this.load.image("wall", "wall.png");
this.load.image("ball", "ball.png");
this.load.image("coin", "coin.png");
}
create(){
var spikeDistance = gameOptions.triangleBase * 1.25;
this.leftSpikes = [];
this.rightSpikes = [];
for(var i = 0; i < 11; i++){
if(i < 7){
this.addSpike(gameOptions.triangleBase + i * spikeDistance, game.config.height - gameOptions.triangleBase / 2);
this.addSpike(gameOptions.triangleBase + i * spikeDistance, gameOptions.triangleBase / 2);
}
this.leftSpikes.push(this.addSpike(- gameOptions.triangleBase / 4, gameOptions.triangleBase * 1.5 + i * spikeDistance));
this.rightSpikes.push(this.addSpike(game.config.width + gameOptions.triangleBase / 4, gameOptions.triangleBase * 1.5 + i * spikeDistance));
}
this.addWall(gameOptions.triangleBase / 4, game.config.height / 2, gameOptions.triangleBase / 2, game.config.height, "leftwall");
this.addWall(game.config.width - gameOptions.triangleBase / 4, game.config.height / 2, gameOptions.triangleBase / 2, game.config.height, "rightwall");
this.addWall(game.config.width / 2, gameOptions.triangleBase / 4, game.config.width - gameOptions.triangleBase, gameOptions.triangleBase / 2, "");
this.addWall(game.config.width / 2, game.config.height - gameOptions.triangleBase / 4, game.config.width - gameOptions.triangleBase, gameOptions.triangleBase / 2, "");
var ballTexture = this.textures.get("ball");
this.ball = this.matter.add.image(game.config.width / 4, game.config.height / 2, "ball");
this.ball.setScale(gameOptions.triangleBase / ballTexture.source[0].width);
this.ball.setBody({
type: "circle",
radius: gameOptions.triangleBase / 2
});
this.ball.setVelocity(gameOptions.ballSpeed, 0);
this.coin = this.matter.add.image(0, 0, "coin");
this.coin.setCircle();
this.coin.setStatic(true);
this.coin.body.isSensor = true;
this.coin.body.label = "coin"
this.coin.setScale(gameOptions.triangleBase / ballTexture.source[0].width);
this.placeCoin();
this.input.on("pointerdown", this.jump, this);
this.matter.world.on("collisionstart", function (e, b1, b2) {
if(b1.label == "spike" || b2.label == "spike"){
this.scene.start("PlayGame");
}
if(b1.label == "leftwall" || b2.label == "leftwall"){
this.setSpikes(true);
this.ball.setVelocity(gameOptions.ballSpeed, this.ball.body.velocity.y);
}
if(b1.label == "rightwall" || b2.label == "rightwall"){
this.setSpikes(false);
this.ball.setVelocity(-gameOptions.ballSpeed, this.ball.body.velocity.y);
}
if(b1.label == "coin" || b2.label == "coin"){
this.placeCoin();
}
}, this);
}
placeCoin(){
this.coin.x = Phaser.Math.Between(game.config.width * 0.2, game.config.width * 0.8);
this.coin.y = Phaser.Math.Between(game.config.height * 0.2, game.config.height * 0.8);
}
addWall(x, y, w, h, label){
var wallTexture = this.textures.get("wall");
var wall = this.matter.add.image(x, y, "wall", null, {
isStatic: true,
label: label
});
wall.setScale(w / wallTexture.source[0].width, h / wallTexture.source[0].width);
}
addSpike(x, y){
var spikeTexture = this.textures.get("spike");
var squareSize = gameOptions.triangleBase / Math.sqrt(2);
var squareScale = squareSize / spikeTexture.source[0].width;
var spike = this.matter.add.image(x, y, "spike", null, {
isStatic: true,
label: "spike"
});
spike.setScale(squareScale);
spike.rotation = Math.PI / 4;
return spike;
}
setSpikes(isRight){
for(var i = 0; i < 11; i++){
if(isRight){
this.rightSpikes[i].x = game.config.width + gameOptions.triangleBase / 4;
}
else{
this.leftSpikes[i].x = - gameOptions.triangleBase / 4;
}
}
var randomPositions = Phaser.Utils.Array.NumberArray(0, 10);
var numberOfSpikes = Phaser.Math.Between(3, 6);
for(i = 0; i < numberOfSpikes; i++){
var randomSpike = Phaser.Utils.Array.RemoveRandomElement(randomPositions);
if(isRight){
this.rightSpikes[randomSpike].x = game.config.width - gameOptions.triangleBase / 2;
}
else{
this.leftSpikes[randomSpike].x = gameOptions.triangleBase / 2;
}
}
}
jump(){
this.ball.setVelocity((this.ball.body.velocity.x > 0) ? gameOptions.ballSpeed : -gameOptions.ballSpeed, -gameOptions.jumpForce);
}
update(){
this.ball.setVelocity((this.ball.body.velocity.x > 0) ? gameOptions.ballSpeed : -gameOptions.ballSpeed, this.ball.body.velocity.y);
}
};
function resize(){
var canvas = document.querySelector("canvas");
var windowWidth = window.innerWidth;
var windowHeight = window.innerHeight;
var windowRatio = windowWidth / windowHeight;
var gameRatio = game.config.width / game.config.height;
if(windowRatio < gameRatio){
canvas.style.width = windowWidth + "px";
canvas.style.height = (windowWidth / gameRatio) + "px";
}
else{
canvas.style.width = (windowHeight * gameRatio) + "px";
canvas.style.height = windowHeight + "px";
}
}
As usual, adding important features is a matter of minutes with Phaser, next time we’ll cover a scoring system and you’ll see the completely commented script, meanwhile download the source code.
Never miss an update! Subscribe, and I will bother you by email only when a new game or full source code comes out.