I am building photo slideshow by building multiple CALayers, assigning cgimage to the layer's contents, and then adding CAAnimations to each layer. Each layer comes off and goes their start time & go after duration(say 3 seconds). None of the animations overlap in time. Finally all layers are added to AVSynchronizedLayer for playback using AVPlayer.
Problem: How do I defer image loading at the time when respective animation runs ? Currently I do imageLayer.contents = (id) self.image.CGImage while building each layer and it adds to memory usage no matter whether it is visible on screen or not.
I also tried setting CALayer contents by animating the contents property as follows :
CABasicAnimation *contentsAnimation = [CABasicAnimation animationWithKeyPath:#"contents"];
contentsAnimation.beginTime = startTime;
contentsAnimation.duration = CMTimeGetSeconds(self.timeRange.duration);
contentsAnimation.fromValue = (id) self.photoImage.CGImage;
contentsAnimation.toValue = (id) self.photoImage.CGImage;
contentsAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
contentsAnimation.fillMode = kCAFillModeForwards;
contentsAnimation.removedOnCompletion = NO;
[imageLayer addAnimation:contentsAnimation forKey:#"contents"];
But the problem is since CGImage is referenced, it adds to memory usage. If you have 20 images, size of dirty memory is too much causing crash.
Ok I found that the solution was simply putting UIImage loading code inside #autoreleasepool { }. I was putting this autoreleasepool{} at the wrong place earlier. It had nothing to do with CoreAnimation as such.
Related
I have a CVPixelBuffer that I'm trying to efficiently draw on screen.
The not-efficient way of turning into an NSImage works but is very slow, dropping about 40% of my frames.
Therefore, I've tried rendering it on-screen using CIContext's drawImage:inRect:fromRect. The CIContext was initialized with a NSOpenGLContext who's view was set to my VC's view. When I have a new image, I call the drawImage method which doesn't spit out any errors... but doesn't display anything on screen either (it did log errors when my contexts were not correctly setup).
I've tried to find an example of how this is done on MacOS, but everything seems to be for iOS nowadays.
EDIT:
Here's some of the code I am using. I've left out irrelevant sections
On viewDidLoad I init the GL and CI contexts
NSOpenGLPixelFormatAttribute pixelFormatAttr[] = {
kCGLPFAAllRenderers, 0
};
NSOpenGLPixelFormat *glPixelFormat = [[NSOpenGLPixelFormat alloc] initWithAttributes: pixelFormatAttr];
NSOpenGLContext *glContext = [[NSOpenGLContext alloc] initWithFormat:glPixelFormat shareContext:nil];
glContext.view = self.view;
self.ciContext = [CIContext contextWithCGLContext:glContext.CGLContextObj pixelFormat:glPixelFormat.CGLPixelFormatObj colorSpace:nil options:nil];
Then, when a new frame is ready, I do:
dispatch_async(dispatch_get_main_queue(), ^{
[vc.ciContext drawImage:ciImage inRect:vc.view.bounds fromRect:ciImage.extent];
vc.isRendering = NO;
});
I am not sure I'm calling draw in the right place, but I can't seem to find out where is this supposed to go.
If the CVPixelBuffer has the kCVPixelBufferIOSurfaceCoreAnimationCompatibilityKey attribute, the backing IOSurface (retrieved via CVPixelBufferGetIOSurface) can be passed directly to the contents property of a CALayer.
This is probably the most efficient way to display a CVPixelBuffer.
I set off to transform an NSImageView. My initially attempt was
self.imageView.wantsLayer = YES;
self.imageView.layer.transform = CATransform3DMakeRotation(1,1,1,1);
Unfortunately I noticed that the transform only happens sometimes (maybe once every 5 runs). Adding an NSLog between confirmed that on some runs self.imageView.layer is null. State of the whole project is shown on the image below.
It's an incredibly simple 200x200 NSImageView with an outlet to a generated NSViewController. Some experimentation showed settings wantsDisplay doesn't fix the problem, but putting the transform on an NSTimer makes it work every-time. I'd love an explanation why this happens (I presume it's due to some race condition).
I'm using Xcode 8 on the macOS 10.12 but I doubt this is the cause of the problem.
Update
Removing wantsLayer and madly enabling Core Animation Layers in Interface Builder did not fix the problem.
Neither did attempts to animate it (I wasn't sure what I was hoping for)
// Sometimes works.. doesn't animate
[NSAnimationContext runAnimationGroup:^(NSAnimationContext *context) {
context.duration = 1;
self.imageView.animator.layer.transform = CATransform3DMakeRotation(1,1,1,1);
} completionHandler:^{
NSLog(#"Done");
}];
or
// Animates but only sometimes
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform"];
animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(1,1,1,1)];
animation.duration = 1;
[self.imageView.layer addAnimation:animation forKey:nil];
After experimenting with allowsImplicitAnimation I realised I might be trying to animate too early.
Moving the transform code into viewDidAppear made it work every time.
- (void)viewDidAppear {
[super viewDidAppear];
self.imageView.animator.layer.transform = CATransform3DMakeRotation(1,1,1,1);
}
i have some problem. So i have code which update song name and picture from php. Song name work and also updated but picture not work, in php file all work but in my project - no. How make update picture from url after 10 sec for example. Thanks.
-(void)viewWillDraw {
NSURL *artistImageURL = [NSURL URLWithString:#"http://site.ru/ParseDataField/kiss.php?image"];
NSImage *artistImage = [[NSImage alloc] initWithContentsOfURL:artistImageURL];
[dj setImage:artistImage];
dispatch_queue_t queue = dispatch_get_global_queue(0,0);
dispatch_async(queue, ^{
NSError* error = nil;
NSString* text = [NSString stringWithContentsOfURL:[NSURL URLWithString:#"http://site.ru/ParseDataField/kiss.php?artist"]
encoding:NSASCIIStringEncoding
error:&error];
dispatch_async(dispatch_get_main_queue(), ^{
[labelName setStringValue:text];
});
});
}
You should really consider placing this code someplace other than -viewWillDraw. This routine can be called multiple times for the same NSView under some circumstances and, more importantly, you need to call [super viewWillDraw] to make sure that things will actually draw correctly (if anything is drawn in the view itself).
For periodic updates (such as every 10 seconds), you should consider using NSTimer to trigger the retrieval of the next object.
As for the general question of why your image isn't being drawn correctly, you should probably consider putting the image retrieval and drawing code into the same structure as your label retrieval and drawing code. This will get the [dj setImage: artistImage] method call outside of the viewWillDraw chain which is likely causing some difficulty here.
I'm trying to create a test app in which the user can pause an animation by clicking in the SceneView. The SceneView loads the animation from a .dae file created in a 3d app (Cinema 4D). The app successfully plays and loops the animation upon launch.
To pause the animation, I used Technical Q&A QA1673 as a reference. In the case of this .dae file, the animation actually comes in as a hierarchy of animations, so I have tried reaching down to each underlying CAKeyframeAnimation and setting its speed to zero. My code currently looks like this:
- (void)mouseDown:(NSEvent *)event {
SCNNode *cubeNode = [self.scene.rootNode childNodeWithName:#"C4D_Cube" recursively:YES];
CAAnimation *cubeAnimation = [cubeNode animationForKey:#"Cube_Anim_01-02-1"];
CAAnimationGroup *cubeAnimationGroup = (CAAnimationGroup *)cubeAnimation;
// cubeAnimationGroup contains 3 CAAnimationGroups, each of which contains a CAKeyframeAnimation.
// So I directly access each CAKeyframeAnimation and set its speed to zero.
for (CAAnimationGroup *subGroup in [cubeAnimationGroup animations]) {
CFTimeInterval pausedTime = CACurrentMediaTime();
[[subGroup animations] setValue:#0.0 forKey:#"speed"];
[[subGroup animations] setValue:[NSNumber numberWithFloat:pausedTime] forKey:#"timeOffset"];
}
}
When I set a breakpoint, I can see that the speed of the keyframe animations does change from 1 to 0, but the animation continues to play at its normal speed in the scene view. I originally tried just setting the speed on the top level CAAnimationGroup to zero, but this also had no effect. What's the correct way to pause an animation in progress?
The animations returned by "animationForKey:" are copies of the running animations.
The documentation says "Attempting to modify any properties of the returned object will result in undefined behavior."
So you could do something like this instead:
for(NSString *key in [myNode animationKeys]){
CAAnimation *animation = [myNode animationForKey:key];
[animation setSpeed:0]; //freeze
[animation setTimeOffset:CACurrentMediaTime() - [animation beginTime]]; //move back in time
[cube addAnimation:animation forKey:key]; //re-add the animation with the same key to replace
}
Note that if you just want to pause all the animations coming from a .DAE you might want to do:
[mySCNView setPlaying:NO]; //pause scene-time based animations
Or you could set paused to true.
In Swift:
mySCNView.scene?.paused = true
SCNScene has [isPaused][1] property which you can set. BTW, so does SKScene cause it is a SKNode.
Re-asking the question:
When you add an animation for the contents key, a CATransitionAnimation is apparently being triggered that fades the original contents property to the first value in the animation's values array, resulting in a .25 second fade. And it looks bad! I have suppressed every animatable property using all the methods discussed here (returning null animations through a delegate, into the actions dictionary, using CATransaction), but none of these seem to be targeting this particular transition animation.
I have been looking into what property could possibly be responsible for this, but cannot figure it out.
I need to suppress the transition animation that is occurring when you add an animation to the contents key.
As I'm at such a loss, I will put the keyframe animation that is being added for you to see. I figure maybe I am doing something wrong here? Just a note, that array is just an array of 6 CGImageRefs (the frames of the animation).
+ (CAKeyframeAnimation *)moveLeftAnimation {
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:#"contents"];
animation.values = [NSArray arrayWithArray:[Setzer walkingLeftSprite]];
animation.duration = 0.5f;
animation.keyTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0],
[NSNumber numberWithFloat:0.2],
[NSNumber numberWithFloat:0.4],
[NSNumber numberWithFloat:0.6],
[NSNumber numberWithFloat:0.8],
[NSNumber numberWithFloat:1.0],
nil];
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
return animation;
}
Also, I have an animation that handles the position key, in the sprite's action dictionary:
+ (CABasicAnimation *)moveAnimation {
CABasicAnimation *moveAnimation = [CABasicAnimation animation];
moveAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
moveAnimation.duration = 0.5f;
return moveAnimation;
}
I am thinking maybe this transition is occurring when you change the layer's position? I don't know...
Please help! This is driving me NUTS!
You can do something along the lines of what I describe in this answer, where I disable the implicit animations for various layer properties by setting the appropriate values in the actions dictionary on that layer.
In your case, I believe something like
NSMutableDictionary *newActions = [[NSMutableDictionary alloc] initWithObjectsAndKeys:
[NSNull null], #"contents",
nil];
layer.actions = newActions;
[newActions release];
should prevent the implicit animation of a layer's contents property until you explicitly animate it.
To prevent any animation, you could set an object as the delegate of your CALayer and then implement the ‑actionForLayer:forKey: delegate method and return a null object:
- (id<CAAction>)actionForLayer:(CALayer*)layer forKey:(NSString*)key
{
if(layer == yourLayer)
{
if([key isEqualToString:#"contents"])
{
return (id<CAAction>)[NSNull null];
}
}
return nil;
}
Here are a few notes on how this puzzle was solved, and how everyone's answers provided a piece of the puzzle.
To restate the problem: when I added a keyframe animation to the #contents key of a CALayer, there appeared to be a .25 second fade transition between the original contents property and the first frame of the keyframe animation. This looked bad, and I wanted to get rid of it.
At first, I thought surely that by using a CATransaction I could suppress this implicit transition animation, as that is what Apple's docs lead you to believe. Using a transaction, I suppressed in every possible way you could imagine, and yet it was still happening. Then I tried returning NULL animations for every animatable property via a dictionary. No luck. Then I did the same thing, but with a delegate. Still no luck.
What I didn't mention is that at the same time the animation was being added and the layer was being moved, two sublayers beneath it were being removed from the their superlayers. I tried adding custom animations for the onOrderOut key, but to no avail. Then I stumbled upon another question here on StackOverflow, about adding a custom animation for the onOrderOut key. It turns out, quite simply, that you can't, and that if you wan to implement some other animation for when a sublayer is removed, you have to use the delagate method animationDidStop. How can I use custom animations for onOrderOut in Core Animation?
So at this point I was convinced that this ghost image had nothing to do with the actual layer in question, the sprite itself. To test this, I just didn't add the sublayers that went beneath it. Sure enough, there was no lingering ghost when I moved the sprite around. It looked perfect. Then I added the layers beneath there was the ghost. It was almost like the sprite's contents were drawn into the layers beneath it, so that when they were removed, there was a sort of imprint.
Instead of removing the sublayers, I just tried hiding them. Bingo. It was perfect. The same fade transition occurred, but there was no imprint of the sprite left. I still don't understand why this is so.
Then, because I still needed to remove those layers, I implemented the animationDidStop delegate method for the sprite's various movement animations to remove them.
This is the original:
This is the new version:
So while I don't understand, technically, why there appears to be an imprint, I am all but certain that it concerns what goes on behind the scenes when you remove a sublayer. Also, for interest sake, I still wanted that sublayer to be hidden on animation start, so I just set it to hidden and provided my own transition animation.
So thanks to everyone for their help. This is a strange use case, I know, but if you are ever thinking of making a 2d sprites-based Final Fantasy Tactics ripoff, then hopefully my pain will be to your benefit!
class AnimationLayer: CALayer {
override class func defaultAction(forKey event: String) -> CAAction? {
let transition = CATransition()
transition.duration = 0
return transition
}
}