JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/phaser/2.4.4/phaser.js"></script>

JavaScript

var earthBMD
var scrollEarthBMD
var earth
var shadow
var size = 250 // diameter of circle
var mapW = 1280 // width of texture
var mapH = 512 // height of texture
var planet // group to put everything in
var newW
var newH

game = new Phaser.Game(640, 480, Phaser.AUTO, '', {
    preload: preload,
    create: create,
    update: update
});

function preload () {
    game.load.crossOrigin = 'anonymous';
    game.load.image("texture", "http://i.imgur.com/G4xEZx3.jpg");
    game.load.image("sphere", "http://i.imgur.com/cyz54kw.png");
    game.load.image("button", "http://i.imgur.com/oS5Q1Jx.png");

};

function create() {

    planet = game.add.group()

    // scale the map to the size of the circle
    newW = (1280/512)*size
    console.log("newW",newW)
    newH = size


    // create bitmapdata to draw on for our sprite
   earthBMD=game.make.bitmapData(size,size,'earthBMD')
  
   // create bitmap data to use for copying scroll to sprite earthBMD
   scrollEarthBMD = game.make.bitmapData(newW+size, newH, 'scrollEarthBMD')
   scrollEarthBMD.copy('texture',0,0,1280,512,0,0,newW,newH);
   scrollEarthBMD.copy('texture',0,0,512,512,newW,0,size,size);

   // make a sprite to display the bitmap data
   earth = game.add.sprite(0,0,earthBMD)
   // add our highlight
   shadow = game.make.sprite(0,0,'sphere')
   
   // center our sprites
   earth.anchor.set(0.5)
   shadow.anchor.set(0.5)
   
   // create a mask
   g = game.add.graphics(0,0)
   g.beginFill(0xFFFFFF,1)
   
   // smooth off the edge by drawing a bit smaller than the sphere which is jagged
  g.drawCircle(0,0,size-2)
 
   
   // rotate our sprite.. no need to rotate the texture
   earth.angle=-15;
   
   // put the earth and the mask into the group to make moving them both simpler
   planet.add(earth)
   planet.add(g)
   planet.add(shadow)
  planet.mask = g

   
   planet.x = game.width/2
   planet.y = game.height/2
   
   // just for debugging
   //earth.inputEnabled = true;
  ...