How to change for 3D rotation on UIPanGesture? - iphone

Question

I have done animation opening a page on tapping on it but now I have to change it for Pan Gesture. How should I start?
[UIView setAnimationDelegate:self];
[UIView commitAnimations];
CALayer *layer = ges.view.layer;
CATransform3D initialTransform = ges.view.layer.transform;
initialTransform.m34 = 1.0 / -1100;
layer.transform = initialTransform;
layer.anchorPoint = CGPointMake(-0.0, 0.5);
[UIView beginAnimations:#"Scale" context:nil];
[UIView setAnimationDuration:2];
[UIView setAnimationCurve: UIViewAnimationCurveEaseInOut];
CATransform3D rotationAndPerspectiveTransform = ges.view.layer.transform;
rotationAndPerspectiveTransform = CATransform3DRotate(rotationAndPerspectiveTransform, -M_PI , 0 , -ges.view.bounds.size.height/2, 0);
ges.view.transform = CGAffineTransformRotate(ges.view.transform, 0);
layer.transform = rotationAndPerspectiveTransform;
[UIView setAnimationDelegate:self];
[UIView commitAnimations];

Answer 1

UIPanGestureRecognizer myPanGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(imagePanned:)];
[_panGesture setMaximumNumberOfTouches:1];
[yourView addGestureRecognizer:myPanGesture];
1) if you want page to turn along with the pan action as user moves the view then you have to do this way.
- (void)imagePanned:(UIPanGestureRecognizer *)iRecognizer {
CGPoint translation = [recognizer translationInView:self.view];
//Calculate transformation based on the translation value of pan gesture, this will be a tricky part
[UIView animateWithDuration:0.5 delay: 0 options: 0 animations:
^(void) {
//Apply transformation
}
completion: nil];
}
Hope this will help you.
Edit : Extended Answer
*This goes with the first idea*
You just want to rotate the view right ?
then use CATransform3D, here you will need to calculate the iAngle that we are applying to view.
iAngle = //Calculate based on translation
where translation is
CGPoint translation = [recognizer translationInView:self.view];
Then apply transformation to view
CATransform3D myTransform = CATransform3DIdentity;
myTransform.m34 = 1.0 / -500;
myTransform = CATransform3DRotate(myTransform, DEGREES_TO_RADIANS(-iAngle), 0.0f, 1.0f, 0.0f); //#define DEGREES_TO_RADIANS(d) (d * M_PI / 180)
yourView.layer.transform = myTransform;

Answer 2

I'll give you the math behind doing it as I don't have code right now to show. Converting finger movement to rotation value is simply a matter of setting up ratios.
For angle value (used in transform):
track_spread rotation_angle
____________ = ______________
movement_x angle = ?
angle = (rotation_angle * movement_x)/track_spread;
WHERE:
track_spread = width_of_your_view (or less e.g. 70% x width_of_your_view)
rotation_angle = the final rotation you want for your view (a constant e.g. 45 degrees)
CGPoint point = [recognizer translationInView:self];
movement_x = abs(point.x);
angle = the value (in degrees) you are interested in and will input into transform after converting to radians
If someone cant figure out and still need code snippet please leave a comment.