var game = new Phaser.Game(800, 600, Phaser.AUTO, 'phaser-example', { preload: preload, create: create, update: update, render: render });

function preload() {

    game.load.image('atari', 'assets/sprites/atari130xe.png');
    game.load.image('mushroom', 'assets/sprites/mushroom2.png');

}

var sprite1;
var sprite2;

function create() {

    game.stage.backgroundColor = '#2d2d2d';

    //  This will check Sprite vs. Sprite collision using a custom process callback

    sprite1 = game.add.sprite(0, 200, 'atari');
    sprite1.name = 'atari';
    //  We'll use a random velocity here so we can test it in our processHandler
    sprite1.body.velocity.x = 50 + Math.random() * 100;
    //  This tells phaser to not use the built-in body separation, instead you should handle it in your process callback (see below)
    sprite1.body.customSeparateX = true;

    sprite2 = game.add.sprite(750, 220, 'mushroom');
    sprite2.name = 'mushroom';
    //  We'll use a random velocity here so we can test it in our processHandler
    sprite2.body.velocity.x = -(50 + Math.random() * 100);
    //  This tells phaser to not use the built-in body separation, instead you should handle it in your process callback (see below)
    sprite2.body.customSeparateX = true;

}

function update() {

    game.physics.collide(sprite1, sprite2, collisionHandler, processHandler, this);

}

function processHandler (obj1, obj2) {

    //  This function can perform your own additional checks on the 2 objects that collided.
    //  For example you could test for velocity, health, etc.
    //  If you want the collision to be deemed successful this function must return true.
    //  In which case the collisionHandler will be called, otherwise it won't.

    //  Note: the objects will have already been separated by this point unless you have set
    //  their customSeparateX/Y flags to true. If you do that it's up to you to handle separation.

    //  Whichever one is going fastest wins, the other dies :)
    if (obj1.body.velocity.x > Math.abs(obj2.body.velocity.x))
    {
        obj2.kill();
        obj1.body.velocity.x = 0;
    }
    else
    {
        obj1.kill();
        obj2.body.velocity.x = 0;
    }

    return true;

}

function collisionHandler (obj1, obj2) {

    game.stage.backgroundColor = '#992d2d';

    console.log(obj1.name + ' collided with ' + obj2.name);

}

function render() {
}