Emanuele Feronato

// the game itself
var game;

var gameOptions = {

    // slices configuration
    slices: [
        {
            startColor: 0xff0000,
            endColor: 0xff8800,
            rings: 3,
            text: "RED/ORANGE"
        },
        {
            startColor: 0x00ff00,
            endColor: 0x004400,
            rings: 200,
            text: "GREEN"
        },
        {
            startColor: 0xff00ff,
            endColor: 0x0000ff,
            rings: 10,
            text: "PURPLE/BLUE"
        },
        {
            startColor: 0x666666,
            endColor: 0x999999,
            rings: 200,
            text: "GREY"
        },
        {
            startColor: 0x000000,
            endColor: 0xffff00,
            rings: 1,
            text: "YELLOW"
        }
    ],

    // wheel rotation duration range, in milliseconds
    rotationTimeRange: {
        min: 3000,
        max: 4500
    },

    // wheel rounds before it stops
    wheelRounds: {
        min: 2,
        max: 11
    },

    // degrees the wheel will rotate in the opposite direction before it stops
    backSpin: {
        min: 1,
        max: 4
    },

    // wheel radius, in pixels
    wheelRadius: 240,

    // color of stroke lines
    strokeColor: 0xffffff,

    // width of stroke lines
    strokeWidth: 5
}

// once the window loads...
window.onload = function() {

    // game configuration object
    var gameConfig = {

        // render type
       type: Phaser.CANVAS,

       // game width, in pixels
       width: 600,

       // game height, in pixels
       height: 600,

       // game background color
       backgroundColor: 0x000000,

       // scenes used by the game
       scene: [playGame]
    };

    // game constructor
    game = new Phaser.Game(gameConfig);

    // pure javascript to give focus to the page/frame and scale the game
    window.focus()
    resize();
    window.addEventListener("resize", resize, false);
}

// PlayGame scene
class playGame extends Phaser.Scene{

    // constructor
    constructor(){
        super("PlayGame");
    }

    // method to be executed when the scene preloads
    preload(){

        // loading assets
        this.load.image("pin", "pin.png");
    }

    // method to be executed once the scene has been created
    create(){

        // calculating the degrees of each slice
        var sliceDegrees = 360 / gameOptions.slices.length;

        // making a graphic object without adding it to the game
        var graphics = this.make.graphics({
            x: 0,
            y: 0,
            add: false
        });

        // looping through each slice
        for(var i = 0; i < gameOptions.slices.length; i++){

            // converting colors from 0xRRGGBB format to Color objects
            var startColor = Phaser.Display.Color.ValueToColor(gameOptions.slices[i].startColor);
            var endColor = Phaser.Display.Color.ValueToColor(gameOptions.slices[i].endColor)

            for(var j = gameOptions.slices[i].rings; j > 0; j--){

                // interpolate colors
                var ringColor = Phaser.Display.Color.Interpolate.ColorWithColor(startColor,endColor, gameOptions.slices[i].rings, j);

                // converting the interpolated color to 0xRRGGBB format
                var ringColorString = Phaser.Display.Color.RGBToString(Math.round(ringColor.r), Math.round(ringColor.g), Math.round(ringColor.b), 0, "0x");

                // setting fill style
                graphics.fillStyle(ringColorString, 1);

                // drawing the slice
                graphics.slice(gameOptions.wheelRadius + gameOptions.strokeWidth, gameOptions.wheelRadius + gameOptions.strokeWidth, j * gameOptions.wheelRadius / gameOptions.slices[i].rings, Phaser.Math.DegToRad(270 + i * sliceDegrees), Phaser.Math.DegToRad(270 + (i  + 1) * sliceDegrees), false);

                // filling the slice
                graphics.fillPath();
            }

            // setting line style
            graphics.lineStyle(gameOptions.strokeWidth, gameOptions.strokeColor, 1);

            // drawing the biggest slice
            graphics.slice(gameOptions.wheelRadius + gameOptions.strokeWidth, gameOptions.wheelRadius + gameOptions.strokeWidth, gameOptions.wheelRadius, Phaser.Math.DegToRad(270 + i * sliceDegrees), Phaser.Math.DegToRad(270 + (i  + 1) * sliceDegrees), false);

            // stroking the slice
            graphics.strokePath();

        }

        // generate a texture called "wheel" from graphics data
        graphics.generateTexture("wheel", (gameOptions.wheelRadius + gameOptions.strokeWidth) * 2, (gameOptions.wheelRadius + gameOptions.strokeWidth) * 2);

        // creating a sprite with wheel image as if it was a preloaded image
        this.wheel = this.add.sprite(game.config.width / 2, game.config.height / 2, "wheel");

        // adding the pin in the middle of the canvas
        this.pin = this.add.sprite(game.config.width / 2, game.config.height / 2, "pin");

        // adding the text field
        this.prizeText = this.add.text(game.config.width / 2, game.config.height - 20, "Spin the wheel", {
            font: "bold 32px Arial",
            align: "center",
            color: "white"
        });

        // center the text
        this.prizeText.setOrigin(0.5);

        // the game has just started = we can spin the wheel
        this.canSpin = true;

        // waiting for your input, then calling "spinWheel" function
        this.input.on("pointerdown", this.spinWheel, this);
    }

    // function to spin the wheel
    spinWheel(){

        // can we spin the wheel?
        if(this.canSpin){

            // resetting text field
            this.prizeText.setText("");

            // the wheel will spin round for some times. This is just coreography
            var rounds = Phaser.Math.Between(gameOptions.wheelRounds.min, gameOptions.wheelRounds.max);

            // then will rotate by a random number from 0 to 360 degrees. This is the actual spin
            var degrees = Phaser.Math.Between(0, 360);

            // then will rotate back by a random amount of degrees
            var backDegrees = Phaser.Math.Between(gameOptions.backSpin.min, gameOptions.backSpin.max);

            // before the wheel ends spinning, we already know the prize according to "degrees" rotation and the number of slices
            var prize = gameOptions.slices.length - 1 - Math.floor((degrees - backDegrees) / (360 / gameOptions.slices.length));

            // now the wheel cannot spin because it's already spinning
            this.canSpin = false;

            // animation tweeen for the spin: duration 3s, will rotate by (360 * rounds + degrees) degrees
            // the quadratic easing will simulate friction
            this.tweens.add({

                // adding the wheel to tween targets
                targets: [this.wheel],

                // angle destination
                angle: 360 * rounds + degrees,

                // tween duration
                duration: Phaser.Math.Between(gameOptions.rotationTimeRange.min, gameOptions.rotationTimeRange.max),

                // tween easing
                ease: "Cubic.easeOut",

                // callback scope
                callbackScope: this,

                // function to be executed once the tween has been completed
                onComplete: function(tween){

                    // another tween to rotate a bit in the opposite direction
                    this.tweens.add({
                        targets: [this.wheel],
                        angle: this.wheel.angle - backDegrees,
                        duration: Phaser.Math.Between(gameOptions.rotationTimeRange.min, gameOptions.rotationTimeRange.max) / 2,
                        ease: "Cubic.easeIn",
                        callbackScope: this,
                        onComplete: function(tween){

                            // displaying prize text
                            this.prizeText.setText(gameOptions.slices[prize].text);

                            // player can spin again
                            this.canSpin = true;
                        }
                    })
                }
            });
        }
    }
}

// pure javascript to scale the game
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";
    }
}