/* DESCRIPTION

utilities.entities.math.TrigCalc
	A trigonometric calculator.

VERSION
	1.0

TYPE
	Static Class
	
HELPERS
	no helper classes needed


METHODS
	
	RELATIVE Calc
		getRelAng(x1,y1, x2,y2);				The relative angle between 2 points (gets radians, and then converts to angle).
		getRelRad(x1,y1, x2,y2);				The relative radians between 2 points.
		getRelDist(x1,y1, x2,y2);				The relative distance between 2 points.
		getRelAngPos(x,y, angle, distance);		Returns an Object with the x,y coordinates of the arrival point, (ANGLE), {x:x,y:y}.
		getRelRadPos(x,y, radians, distance);		Returns an Object with the x,y coordinates of the arrival point, (RADIANS), {x:x,y:y}.
	
	ABSOLUTE Calc (all is relative to ZERO)
		getAng(x,y);						Returns the ANGLE.
		getRad(x,y);						Returns the RADIANS.
		getDist(x,y);						Returns the DISTANCE.
		getAngPos(angle,distance);			Returns COORDINATES object {x:x,y:y} from angle and distance.
		getRadPos(radians,distance);			Returns COORDINATES object {x:x,y:y} from radians and distance.
	

USAGE

	var a = TrigCalc.getRelAngle(x1,x2, y1,y2);
	trace("angle is: " + a);
	
	var c = TrigCalc.getAngPos(angle, distance);
	trace("x: " + c.x + " y: " + c.y);


*/


/* ANALISYS
*/




class PippoFlash.TrigCalc {

	private static var radMult = Math.PI*2; 			// Constant to extrat radians from distance
	private static var angMult = 180/Math.PI; 		// Constant to convert radians to angle
	
	
// RELATIVE Calculations //////////////////////////////////////////////////////////////////////////////////////
	
	// Finds the ANGLE between 2 points
	static function getRelAng(x,y,x1,y1)				:Number 	{	
		return radToAng(getRelRad(x,y,x1,y1));
	}
	
	// Finds the RADIANS between 2 points
	static function getRelRad(x,y,x1,y1) 				:Number 	{
		return (y1-y)<0 ? radMult-Math.acos((x1-x)/getRelDist(x,y,x1,y1)) : Math.acos((x1-x)/getRelDist(x,y,x1,y1));
	}
	
	// Finds the DISTANCE between 2 points
	static function getRelDist(x,y,x1,y1) 				:Number 	{	
		return Math.sqrt(Math.pow((x1-x),2)+Math.pow((y1-y),2));
	}
	
	// Returns  X,Y position from angle and distance
	static function getRelAngPos(x,y,a,d) 				:Object 	{
		return getRelRadPos(x,y,angToRad(a),d);
	}
	
	// Returns  X,Y position from radians and distance
	static function getRelRadPos(x,y,r,d) 				:Object	{
		return {x:x+(d*Math.cos(r)),y:y+(d*Math.sin(r))};
	}
	
// ABSOLUTE Calculations //////////////////////////////////////////////////////////////////////////////////////
	
	// finds the ANGLE relative to 0
	static function getAng(x,y) 						:Number 	{
		return radToAng(getRad(x,y));
	}
	
	// finds the RADIANS relative to 0
	static function getRad(x,y) 						:Number 	{		
		return y<0 ? radMult-Math.acos(x/getDist(x,y)) : Math.acos(x/getDist(x,y));
	}
	
	// finds the DISTANCE from 0
	static function getDist(x,y) 						:Number 	{		
		return Math.sqrt(Math.pow(x,2)+Math.pow(y,2));
	}
	
	// Returns  X,Y position from angle and distance
	static function getAngPos(a,d) 					:Object 	{ 		
		return getRadPos(angToRad(a),d);
	}
	
	// Returns  X,Y position from radians and distance
	static function getRadPos(r,d)					:Object 	{
		return {x:d*Math.cos(r),y:d*Math.sin(r)};
	}
	
// CONVERSION //////////////////////////////////////////////////////////////////////////////////////////
	
	// From ANGLE to RADIANS
	static function angToRad(a) 					:Number 	{
		return a/angMult;
	}
	
	// From RADIANS to ANGLE
	static function radToAng(r) 						:Number 	{
		return r*angMult;
	}
	
// COMPLEX Calculations //////////////////////////////////////////////////////////////////////////////////	
	// Complex Functions
	static function rotateRad(x,y,rot) {
		var d = getDist(x,y);
		var r = (y<0 ? radMult-Math.acos(x/d) : Math.acos(x/d))+rot;
		return getRadPos(r,d);
	}
}