/*
 *  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;
}