Max/Min Scale of Pinch Zoom in UIPinchGestureRecognizer - iPhone iOS

Question

How would I be able to limit the scale of the UIPinchGestureRecognizer to a min and max level? The scale property below seems to be relative to the last known scale (the de

Answer 1

- (void)pinchToZoom:(UIPinchGestureRecognizer*)gesture
{
    switch (gesture.state)
    {
        case UIGestureRecognizerStateBegan:
        {
            lastScale = gesture.scale;
        }break;
        case UIGestureRecognizerStateChanged:
        {   
            const CGFloat zoomSensitivity = 5;
            const CGFloat zoomMin = 1;
            const CGFloat zoomMax = 16;

            CGFloat objectScale = gesture.view.contentScaleFactor;
            CGFloat zoomDiff = lastScale - gesture.scale;
            CGFloat zoomDirty = objectScale - zoomDiff * zoomSensivity;
            CGFloat zoomTo = fmaxf(zoomMin, fminf(zoomDirty, zoomMax));

            // step round if needed (neutralize elusive changes)
            zoomTo = (NSInteger)(zoomTo * 10) * 0.1;

            if ( objectScale != zoomTo )
                gesture.view.contentScaleFactor = zoomTo;

            lastScale = gesture.scale;
        }break;
        default:
            break;
    }
}