Key-Frame Animation appears fuzzy when moving Frames? - ios

Question

I use JazzHands to create a key frame based animation in a UIScrollView.
Here is an example. Look at the view at the top. When you move from page to page. While the animation is running the view at the top is slightly moving from left to right. The animation appears a bit fuzzy.
Here is the code taken from the example here:
IFTTTFrameAnimation *titleView1FrameAnimation = [IFTTTFrameAnimation new];
titleView1FrameAnimation.view = self.titleView1;
[self.animator addAnimation:titleView1FrameAnimation];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(1)
andFrame:self.titleView1.frame]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(2)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(2), 0)]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(3)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(3), 0)]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(4)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(4), 0)]];
When running the demo take a look at the part marked with red in the following screenshot:
Edit: Here is the code containing this problem: https://github.com/steffimueller/Intro-Guide-View-for-Talk.ai
How can I make the animation running smooth and less fuzzy?

Answer 1

This is due to the frame rate in the JazzHands IFTTTAnimatedScrollViewController being set for non-retina displays. You need to double the number in timeForPage, and also use double the number of the contentOffset in animate, but use the original non-doubled values of timeForPage in places where you were using that for laying out the positions of views instead of using it for the animation time.
Here's a Gist of the changes you'd have to make to your example to get it working. Fixed Demo Gist
You need this method for setting the animation times:
#define timeForPage(page) (NSInteger)(self.view.frame.size.width * (page - 1) * 2.0)
And this one for setting the centers of your views based on the page dimensions:
#define centerForPage(page) (NSInteger)(self.view.frame.size.width * (page - 1))
Then you need to override the scrollViewDidScroll: method in IFTTTAnimatedScrollViewController to use double the numbers it's currently using.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
[self.animator animate:(NSInteger)(scrollView.contentOffset.x * 2)];
}
We'll work on getting the JazzHands demo updated!

Answer 2

Before you start your animation call:
view.layer.shouldRasterize = YES; (seems that you are using objective-c so I put YES here, for swift should be true)
As soon as the animation is finished call
view.layer.shouldRasterize = NO; (seems that you are using objective-c so I put NO here, for swift should be false)
You should always use it when you animating a view
You can see more details about it in the WWDC 2012 Polishing Your Interface Rotations video (paid developer subscription needed)
I hope that helps you!
[EDIT]
Every Time you call the method animate set shouldRasterize to YES before it, like in the example bellow:
titleView1FrameAnimation.view.layer.shouldRasterize = YES;
[self. titleView1FrameAnimation animate:scrollView.contentOffset.x];

Answer 3

I've messed around a bit with the code and it seems that keeping those top views in place while the scrollview is scrolling made it jiggle left and right.
What I did is take out the title view from the scroll view and add it to the view controller view.
You can see it in action here
Later edit:
To actually see what I've changed you can check the file differences in Git. Basically I moved your titleViews (titleView1, titleView2, etc) from the scrollView to the view controller's view (so basically I've replaced all the lines that were like this:
[self.scrollView addSubView:self.titleView1]
to something like this:
[self.view addSubView:self.titleView1]
After that I've also took out the keyframe animations that were keeping your title views in place since they were not moving with the scrollview anymore. Practically I've deleted all the lines that were adding a frame animation to your titleviews from each configurePageXAnimation.
2nd question answer:
Say your screenshot view is called screenshotView. You can go ahead and create it like this:
UIImageView *screenshotView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"ScreenshotImage"]];
[self.view addSubview:screenshotView];
self.screenshotView = screenshotView;
[self.screenshotView setCenter:CGPointMake(self.view.center.x + self.view.bounds.size.width, <#yourDesiredY#>)];
And animate it like this:
//screenshotView frame animation
IFTTTFrameAnimation *screenshotViewFrameAnimation = [IFTTTFrameAnimation new];
screenshotViewFrameAnimation.view = self.screenshotView;
[self.animator screenshotViewFrameAnimation];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(1) andFrame:self.screenshotView.frame]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(2) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width, 0.0)]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(3) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width, 0.0)]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(4) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width * 2, 0.0)]];