Pinch Issues

Hey guys,
So I implemented pinching. When I hold the option key and pinch outwards it works, but when I loaded it on my iPhone I can't pinch.

Does anyone have these issues or know how to solve it? I'm following the chapter in "Beginning iPhone Development".

Thanks.

 

By the way, I'm using "Beginning iPhone Development" and they have provided a class...

Code:

#include "CGPointUtils.h"
#include <math.h>

#define pi 3.14159265358979323846
#define degreesToRadian(x) (pi * x / 180.0)
#define radiansToDegrees(x) (180.0 * x / 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);
	//degs = degrees(atan((top - bottom)/(right - left)))
}
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);
}

And so I use touchesEnded to do:

Code:

if([touches count] == 2)
	{
		NSArray *twoTouches = [touches allObjects];
		UITouch *first = [twoTouches objectAtIndex:0];
		UITouch *second = [twoTouches objectAtIndex:1];
		CGFloat currentDistance = distanceBetweenPoints([first locationInView:self.view], [second locationInView:self.view]);
		
		if(initialDistance == 0)
			initialDistance = currentDistance;
if(currentDistance - initialDistance > kMinimumPinchDelta)
		{
			//Outward Pinch
                        NSLog(@"Pinch");
		}

And somehow it's not responding. I can do it in the simulator by holding the option key, but it doesn't work on my iPhone. I know it's not my pinching technique cause someone else has tried it and it doesn't work for them...

Thanks for your help.