bit's quest #7

bq7.js

/*
 * Not only does your robot come equipped with sensors and thrusters. It also
 * has a radar that can be used to determine distances.
 *
 * The radar has two methods:
 *
 *
 *  - angle()       - the current direction the radar is pointing (0-359)
 *  - angle(number) - set the radar direction (0-359)
 *
 *  - ping()        - fires the radar
 *
 * One of two events will return after firing the radar:
 *  - 'radar:hit'   - an object was found
 *  - 'radar:miss'  - no object was found
 *
 * When a hit event is received, the handler will receive the angle the
 * ping was sent out on and the distance to the object, e.g.,
 *    this.on('radar:hit', function(angle, distance) {
 *       // do stuff
 *    });
 *
 *  Bonus info: 
 *
 *      Those red jumpy things will kill your robot. Don't touch them.
 */

var stop = function(self) {
	self.thrusters.top(false);
	self.thrusters.left(false);
	self.thrusters.bottom(false);
	self.thrusters.right(false);
}

this.on("start", function(){
	this.thrusters.left(true);
  	this.radar.angle(0);
	this.radar.ping();
});

var to_the_left = 0,
    to_the_right = 500;

this.on('radar:hit', function(angle, distance) {
	if (angle == 0) {
      	to_the_right = distance;
    	this.radar.angle(180);
    } else {
      	to_the_left = distance;
    	this.radar.angle(0);
    }

  	if (Math.abs(to_the_left - to_the_right) < 15) {
        stop(this);
		this.thrusters.top(true);
	}
    else {
  		this.radar.ping();
    }
});

this.on("sensor:bottom", function(foo){
	if (foo) {
		stop(this);
	  	this.thrusters.left(true);
    }
});

this.on("sensor:right", function(foo){
  	this.thrusters.bottom(true);
});