/*

 *  CGPointUtils.c

 *  PinchMe

 *

 *  Created by Jeff LaMarche on 8/2/08.

 *  Copyright 2008 __MyCompanyName__. All rights reserved.

 *

 */

#include "CGPointUtils.h"

#include <math.h>

#define degreesToRadian(x) (M_PI * x / 180.0)

#define radiansToDegrees(x) (180.0 * x / M_PI)

CGFloat distanceBetweenPoints (CGPoint first, CGPoint second) {

	CGFloat deltaX = second.x - first.x;

	CGFloat deltaY = second.y - first.y;

	return sqrt(deltaX*deltaX + deltaY*deltaY );

}

CGFloat angleBetweenPoints(CGPoint first, CGPoint second) {

	CGFloat height = second.y - first.y;

	CGFloat width = first.x - second.x;

	CGFloat rads = atan(height/width);

	return radiansToDegrees(rads);

}

CGFloat angleBetweenLines(CGPoint line1Start, CGPoint line1End, CGPoint line2Start, CGPoint line2End) {

	CGFloat a = line1End.x - line1Start.x;

	CGFloat b = line1End.y - line1Start.y;

	CGFloat c = line2End.x - line2Start.x;

	CGFloat d = line2End.y - line2Start.y;

	CGFloat rads = acos(((a*c) + (b*d)) / ((sqrt(a*a + b*b)) * (sqrt(c*c + d*d))));

	return radiansToDegrees(rads);

}