Talking about Space is Key game, Game development, HTML5, Javascript and Phaser.
So we have our Space is Key game buikt with Phaser 2.6.2 though three steps: first we created the floors and make the player run and jump, then we added deadly obstacles to be avoided as well as some level design concepts and in 3rd step we made the player die with a particle explosion when the square hits an obstacle. Now we are adding colors to the game as well as backgrounds. And guess what, we’ll make it while continuing to use just the same graphic resource. I also added a couple of new floors: Click or tap to jump, now each floor has its own randomly picked colors thanks toremoveRandomItem
method, you can find a full list of Phaser array utilities in the post understanding Phaser array utilities using ArrayUtils class, have a look at it if you didn’t already, it’s full of useful information.
The commented source code with the new lines highlighted is here:
<pre class="wp-block-syntaxhighlighter-code">// the game itself
var game;
// global object with all game options
var gameOptions = {
// game width
gameWidth: 750,
// game height
gameHeight: 720,
// width of each floor
floorWidth: 750,
// height of each floor
floorHeight: 20,
// height of each level
levelHeight: 120,
// array with vertical floors potision
floorY: [100, 220, 340, 460, 580, 700],
// horizontal floor position
floorX: 0,
// size of the hero
squareSize: 16,
// horizontal speed of the hero
squareSpeed: 170,
// game gravity
squareGravity: 450,
// force to be applied at each jump
jumpForce: -210,
// jump tween length, in milliseconds
jumpTime: 300,
// colors used in the game
levelColors: [0xe81d62, 0x9b26af, 0x2095f2, 0x4bae4f, 0xfeea3a, 0x795548, 0x5f7c8a]
}
// this is where we store level information
// gameLevels is an array.
// each gameLevel item is an array with floor information
// each gameLevel[floor] item is an object with:
// * obstacle width
// * obstacle height
// * obstacle position
var gameLevels = [
// floor 0
[
{
width: 60,
height: 30,
x: 200
},
{
width: 60,
height: 30,
x: 400
}
],
// floor 1
[
{
width: 40,
height: 30,
x: 250
},
{
width: 70,
height: 25,
x: 450
},
{
width: 30,
height: 20,
x: 100
}
],
// floor 2
[
{
width: 10,
height: 35,
x: 150
},
{
width: 10,
height: 35,
x: 300
},
{
width: 10,
height: 35,
x: 550
}
],
// floor 3
[
{
width: 80,
height: 10,
x: 280
},
{
width: 80,
height: 10,
x: 480
}
],
// floor 4
[
{
width: 10,
height: 10,
x: 100
},
{
width: 10,
height: 10,
x: 200
},
{
width: 10,
height: 10,
x: 300
},
{
width: 10,
height: 10,
x: 400
},
{
width: 10,
height: 10,
x: 500
},
{
width: 10,
height: 10,
x: 600
}
],
// floor 5
[
{
width: 10,
height: 40,
x: 350
}
]
]
// when the window loads
window.onload = function() {
// game creation
game = new Phaser.Game(gameOptions.gameWidth, gameOptions.gameHeight);
// adding game state
game.state.add("TheGame", TheGame);
// starting game state
game.state.start("TheGame");
}
var TheGame = function(){};
TheGame.prototype = {
// when the state preloads
preload: function(){
// setting the game on maximum scale mode
game.scale.scaleMode = Phaser.ScaleManager.SHOW_ALL;
game.scale.pageAlignHorizontally = true;
game.scale.pageAlignVertically = true;
// preloading the only game assets, a tile which will be used both for the square and the floor
game.load.image("tile", "assets/sprites/tile.png");
},
// once the state is ready
create: function(){
// bakckround group
this.bgGroup = game.add.group();
// creation of a group where we will place all floors
this.groundGroup = game.add.group();
// creation of a group where we will place all spikes, or obstacles, or whatever you will name them
this.spikeGroup = game.add.group();
// we start on the first floor
this.levelFloor = 0;
// adding the hero
this.theSquare = game.add.sprite(0, 0, "tile");
// setting hero registration point
this.theSquare.anchor.set(0.5);
// setting hero width and height
this.theSquare.width = gameOptions.squareSize;
this.theSquare.height = gameOptions.squareSize;
// chen the hero jump?
this.theSquare.canJump = true;
// enabling ARCADE physics on the hero
game.physics.enable(this.theSquare, Phaser.Physics.ARCADE);
// setting hero horizontal velocity
this.theSquare.body.velocity.x = gameOptions.squareSpeed;
// gravity applied to the square
this.theSquare.body.gravity.y = gameOptions.squareGravity;
// a custom attribute to tell the player which color we are going to use at each floor
this.theSquare.squareColor = [];
// time to create the floors
for(var i = 0; i < gameOptions.floorY.length; i++){
// colorsArray will contain a copy of levelColors array
var colorsArray = gameOptions.levelColors.slice();
// background
var bg = game.add.tileSprite(gameOptions.floorX, gameOptions.floorY[i] - gameOptions.levelHeight, gameOptions.floorWidth, gameOptions.levelHeight, "tile");
// which color are we going to tint the square when crossing this floor?
this.theSquare.squareColor[i] = Phaser.ArrayUtils.removeRandomItem(colorsArray);
// applying a random tint color to background
bg.tint = Phaser.ArrayUtils.removeRandomItem(colorsArray);
// setting background semi-transparent to make it look darker thanks to black canvas color
bg.alpha = 0.5;
// adding the background to its proper group
this.bgGroup.add(bg);
// each floor is a tile sprite
var floor = game.add.tileSprite(gameOptions.floorX, gameOptions.floorY[i], gameOptions.floorWidth, gameOptions.floorHeight, "tile");
// applying a random tint color to floor
floor.tint = Phaser.ArrayUtils.removeRandomItem(colorsArray);
// let's enable ARCADE physics on floors too
game.physics.enable(floor, Phaser.Physics.ARCADE);
// floors can't move
floor.body.immovable = true;
// adding the floor to ground group
this.groundGroup.add(floor);
// time to place the spikes
// let's loop through this level spikes
for(var j = 0; j < gameLevels[i].length; j++){
// creating the spike as a tileSprite
var spike = game.add.tileSprite(gameOptions.floorX + gameLevels[i][j].x, gameOptions.floorY[i], gameLevels[i][j].width, gameLevels[i][j].height, "tile");
// applying spikes the same tint color used for the ground
spike.tint = floor.tint;
// setting spike anchor point
spike.anchor.set(0.5, 1);
// enabling ARCADE physics to the spike
game.physics.enable(spike, Phaser.Physics.ARCADE);
// spikes can't move
spike.body.immovable = true;
// adding the spike to spike group
this.spikeGroup.add(spike);
}
}
// placing a particle emitter at coordinates 0, 0 (we'll place it in its proper position later) which can fire up to 30 particles
this.emitter = game.add.emitter(0, 0, 30);
// our particle is the same old "tile" image
this.emitter.makeParticles("tile");
// setting a gravity for each particle
this.emitter.gravity = 200;
// particles would be too big, so let's set their min and max scale.
this.emitter.maxParticleScale = 0.1;
this.emitter.minParticleScale = 0.05;
// finally placing the hero
this.placeSquare();
// waiting for player input, then call squareJump function
game.input.onDown.add(this.squareJump, this);
},
// at each frame
update: function(){
// making the hero collide with floors so it won't fallo down
game.physics.arcade.collide(this.theSquare, this.groundGroup);
// checking if the hero overlaps with anything in spike group
game.physics.arcade.overlap(this.theSquare, this.spikeGroup, function(){
// placing the emitter over the player
this.emitter.x = this.theSquare.x;
this.emitter.y = this.theSquare.y;
// firing 10 particles at once with a 1000 milliseconds lifespan
this.emitter.start(true, 1000, null, 10);
// tinting particles with the same player color
this.emitter.forEach(function(particle) {
particle.tint = this.theSquare.tint;
}, this);
// placing the player at the beginning of the floor
this.placeSquare();
}, null, this);
// if the hero leaves the floor to the right or to the left...
if((this.theSquare.x > gameOptions.floorX + gameOptions.floorWidth && this.levelFloor % 2 == 0) || (this.theSquare.x < gameOptions.floorX && this.levelFloor % 2 == 1)){
// increasing floor number or setting it back to zero
this.levelFloor = (this.levelFloor + 1) % gameOptions.floorY.length;
// placing player at the beginning of the floor
this.placeSquare();
}
// if the hero as its feet on the ground, it can jump
if(this.theSquare.body.touching.down){
this.theSquare.canJump = true;
}
},
// when the player starts running on a floor
placeSquare: function(){
// properly tint the square according to floor number
this.theSquare.tint = this.theSquare.squareColor[this.levelFloor];
// adjusting hero speed according to floor number: from left to right on even floors, from right to left on odd floors
this.theSquare.body.velocity.x = (this.levelFloor % 2 == 0) ? gameOptions.squareSpeed : -gameOptions.squareSpeed;
// no vertical velocity
this.theSquare.body.velocity.y = 0;
// the hero can jump again
this.theSquare.canjump = true;
// adjusting hero vertical and horizontal position
this.theSquare.y = gameOptions.floorY[this.levelFloor] - gameOptions.squareSize / 2;
this.theSquare.x = (this.levelFloor % 2 == 0) ? gameOptions.floorX : gameOptions.floorX + gameOptions.floorWidth;
// stopping the jump tween if running
if(this.jumpTween && this.jumpTween.isRunning){
this.jumpTween.stop();
this.theSquare.angle = 0;
}
},
// when the player jumps
squareJump: function(){
// if the hero can jump...
if(this.theSquare.canJump){
// preventing it to jump while in the air
this.theSquare.canJump = false;
// adding a vertical force to the player
this.theSquare.body.velocity.y = gameOptions.jumpForce;
// setting a jump rotation angle just to make the square rotate
var jumpAngle = this.levelFloor % 2 == 0 ? 180 : -180;
// using a tween to rotate the player
this.jumpTween = game.add.tween(this.theSquare).to({
angle: this.theSquare.angle + jumpAngle
}, gameOptions.jumpTime, Phaser.Easing.Linear.None, true);
}
}
}</pre>
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