/*

 *  CGPointUtils.c

 *  PinchMe

 *

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

 *  Copyright 2008 __MyCompanyName__. All rights reserved.

 *

 */

#include "CGPointUtils.h"

#include "math.h"

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);

}

CGFloat CGPointDot(CGPoint a,CGPoint b) {

    return a.x*b.x+a.y*b.y;

}

CGFloat CGPointLen(CGPoint a) {

    return sqrtf(a.x*a.x+a.y*a.y);

}

CGPoint CGPointSub(CGPoint a,CGPoint b) {

    CGPoint c = {a.x-b.x,a.y-b.y};

    return c;

}

CGFloat CGPointDist(CGPoint a,CGPoint b) {

    CGPoint c = CGPointSub(a,b);

    return CGPointLen(c);

}

CGPoint CGPointNorm(CGPoint a) {

    CGFloat m = sqrtf(a.x*a.x+a.y*a.y);

    CGPoint c;

    c.x = a.x/m;

    c.y = a.y/m;

    return c;

}