IOS CATransform3DMakeRotation need help with vectors

Question

I am trying to flip an animation of a page and found this code on the Internet. It works great. It invalidates the page rotation from right to left, like a regular book. I want to change the code so that it goes from left to right, but I cannot understand how vectors and anchors work. Please note that these two lines that I think of need to be changed. I'm just not sure that ...

viewToOpen.layer.anchorPoint = CGPointMake(0.0f, 0.5f); viewToOpen.center = CGPointMake(viewToOpen.center.x - viewToOpen.bounds.size.width/2.0f, viewToOpen.center.y); CATransform3D endTransform = CATransform3DMakeRotation(3.141f/2.0f, 0.0f, -1.0f, 0.0f); 

Full function here:

 - (void) pageOpenView:(UIView *)viewToOpen duration:(NSTimeInterval)duration { // Remove existing animations before stating new animation [viewToOpen.layer removeAllAnimations]; // Make sure view is visible viewToOpen.hidden = NO; // disable the view so it's not doing anythign while animating viewToOpen.userInteractionEnabled = NO; // Set the CALayer anchorPoint to the left edge and // translate the button to account for the new // anchorPoint. In case you want to reuse the animation // for this button, we only do the translation and // anchor point setting once. if (viewToOpen.layer.anchorPoint.x != 0.0f) { viewToOpen.layer.anchorPoint = CGPointMake(0.0f, 0.5f); viewToOpen.center = CGPointMake(viewToOpen.center.x - viewToOpen.bounds.size.width/2.0f, viewToOpen.center.y); } // create an animation to hold the page turning CABasicAnimation *transformAnimation = [CABasicAnimation animationWithKeyPath:@"transform"]; transformAnimation.removedOnCompletion = NO; transformAnimation.duration = duration; transformAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; // start the animation from the current state transformAnimation.fromValue = [NSValue valueWithCATransform3D:CATransform3DIdentity]; // this is the basic rotation by 90 degree along the y-axis CATransform3D endTransform = CATransform3DMakeRotation(3.141f/2.0f, 0.0f, -1.0f, 0.0f); // these values control the 3D projection outlook endTransform.m34 = 0.001f; endTransform.m14 = -0.0015f; transformAnimation.toValue = [NSValue valueWithCATransform3D:endTransform]; // Create an animation group to hold the rotation CAAnimationGroup *theGroup = [CAAnimationGroup animation]; // Set self as the delegate to receive notification when the animation finishes theGroup.delegate = self; theGroup.duration = duration; // CAAnimation-objects support arbitrary Key-Value pairs, we add the UIView tag // to identify the animation later when it finishes [theGroup setValue:[NSNumber numberWithInt:viewToOpen.tag] forKey:@"viewToOpenTag"]; // Here you could add other animations to the array theGroup.animations = [NSArray arrayWithObjects:transformAnimation, nil]; theGroup.removedOnCompletion = NO; // Add the animation group to the layer [viewToOpen.layer addAnimation:theGroup forKey:@"flipViewOpen"]; } 

Answer 1

This may depend on the level and configuration of the view, but substantially

 viewToOpen.layer.anchorPoint = CGPointMake(1.0f, 0.5f); CATransform3D endTransform = CATransform3DMakeRotation(-M_PI/2.0f,0.0f,1.0f,0.0f) 

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The full code will look like this:

 self.layer.anchorPoint = CGPointMake(1.0f, 0.5f); self.layer.position = CGPointMake(self.layer.position.x + self.bounds.size.width/2.0f, self.layer.position.y); CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"]; animation.duration = 0.75f; animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; CATransform3D tfm = CATransform3DMakeRotation(M_PI/2.0f, 0.0f, -1.0f, 0.0f); tfm.m34 = 0.001f; tfm.m14 = -0.0015f; animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DIdentity]; animation.toValue = [NSValue valueWithCATransform3D:tfm]; [self.layer addAnimation:animation forKey:@"flipUp"];