A set of utilities for FightCode.

CSUtil.js

/* I prefer the singleton class creation method. */
var CSUtil = {
	TWO_PI: Math.PI * 2,
	TO_DEG: 180/Math.PI,

	/**
	 * Returns the angle from x1y1 to x2y2. This function will accept
	 * robot.position, scannedRobot.position, and wrap.
	 */
	angleTo: function(p,q) {
		return Math.atan2(p.y-q.y,p.x-q.x);
	},

	/**
	 * Returns the distance from p to q. This function will accept
	 * robot.position, scannedRobot.position, and wrap.
	 */
	distance: function(p,q) {
		var tmp = 0;
		return Math.sqrt((tmp=(p.x-q.x))*tmp + (tmp=(p.y-q.y))*tmp);
	},

	/**
	 * Returns the square of the distance from p to q. This function will 
	 * accept robot.position, scannedRobot.position, and wrap.
	 */
	distanceSq: function(p,q) {
		var tmp = 0;
		return (tmp=(p.x-q.x))*tmp + (tmp=(p.y-q.y))*tmp;
	},

	/**
	 * Normalizes an angle to an absolute angle. The normalized angle will
	 * be in the range from 0 to 2*PI, where 2*PI itself is not included.
	 */
	normalAbsoluteAngle: function(angle) {
		return (angle %= this.TWO_PI) >= 0 ? angle : (angle + this.TWO_PI);
	},

	/**
	 * Normalizes an angle to an absolute angle. The normalized angle will
	 * be in the range from 0 to 360, where 360 itself is not included.
	 */
	normalAbsoluteAngleDegrees: function(angle) {
		return (angle %= 360) >= 0 ? angle : (angle + 360);
	},

	/**
	 * Normalizes an angle to a relative angle. The normalized angle will 
	 * be in the range from -PI to PI, where PI itself is not included.
	 */
	normalRelativeAngle: function(angle) {
		return (angle %= this.TWO_PI) >= 0 ? (angle < Math.PI) ? angle
			: angle - this.TWO_PI : (angle >= -Math.PI) ? angle : angle
			+ this.TWO_PI;
	},

	/**
	 * Normalizes an angle to a relative angle.
	 * The normalized angle will be in the range from -180 to 180, where 180
	 * itself is not included.
	 */
	normalRelativeAngleDegrees: function(angle) {
		return (angle %= 360) >= 0 ? (angle < 180) ? angle : angle - 360
			: (angle >= -180) ? angle : angle + 360;
	},

	/**
	 * Calculates a location given a start location and an angle and distance
	 * from that location. This function will accept robot.position,
	 * scannedRobot.position, and wrap.
	 */
	project: function(start,angle,length) {
		return {
			x: start.x + Math.cos(angle) * length,
			y: start.y + Math.sin(angle) * length
		};
	},

	/**
	 * Returns 1 if the value is greater than 0,
	 * Returns -1 if the value is less than 0,
	 * Returns 0 if the value is equal to 0.
	 */
	signum: function(value) {
		if(value > 0) return 1;
		if(value < 0) return -1;
		return 0;
	},

	/**
	 * Coverts a angle in radians to an angle in degrees.
	 */
	toDegrees: function(rad) {
		return rad*this.TO_DEG;
	},

	/**
	 * Coverts a angle in degrees to an angle in radians.
	 */	
	toRadians: function(deg) {
		return deg/this.TO_DEG;
	},

	/**
	 * Wraps a set of coordinates in a javascript object.
	 */
	wrap: function(x,y) {
		return {
			x: x,
			y: y
		};
	}
};