CODEWITHSUNDEEP
iphoneobjective-ccalayercgpathcakeyframeanimation
Lakshmi
Lakshmi

Reputation: 585

How to get position during animation which uses CALayer and CGPath in iPhone

 hI,

 I am workng on animation using CALayer and CAPath.

 Here I am animating an Image from top to bottom of screen.I gave starting and ending position for
 the animation.Now, I want to get position  during the animation.

Sample Code:

   - (void)onTimer
    {

    CGImageRef imageRef = [[UIImage imageNamed:@"apple.png"] CGImage];
int startX                      = round(random() % 460);
double speed     = 1 / round(random() %100) + 1.0;

layer          = [CALayer layer];
layer.name              = @"layer";
layer.contents          = (id)imageRef; // cached image
layer.frame             = CGRectMake(startX, self.view.frame.size.height+10,    CGImageGetWidth(imageRef), CGImageGetHeight(imageRef));

[mView.layer addSublayer:layer];


 path = CGPathCreateMutable(); 
CGPathMoveToPoint(path, NULL, startX, -100);
CGPathAddLineToPoint(path, NULL, startX, self.view.frame.size.height+10);



CAKeyframeAnimation *animation= [CAKeyframeAnimation animationWithKeyPath:@"position"];

animation.delegate=self;

animation.duration= 10*speed;
animation.autoreverses=NO;
animation.path=path;
animation.repeatCount = 0;
animation.removedOnCompletion=YES;
animation.calculationMode = kCAAnimationLinear;

[layer addAnimation:animation forKey:@"position"];


CGPoint point= CGPathGetCurrentPoint(path);


   }

    In this I used "CGPathGetCurrentPoint" method but it did not work. Also used 
     presentationLayer method of CALayer but uit also did not work in this case.

     Can anyone suggest the code to get the position during animation
    thanks in advance

Upvotes: 1

Views: 1116

Answers (2)

devinkb
devinkb

Reputation: 191

You can get the value of what you see on the screen during an animation by looking at the properties on the layer's presentationLayer.

Upvotes: 2

pe8ter
pe8ter

Reputation: 1263

Core Animation was not designed for this. Its job is to handle property animation for you, not expose you to it.

If you want to know its position during animation, then you'll need to do all the animation yourself without Core Animation.

CGPathGetCurrentPoint() is a function that accesses control points of CGPath instances, not Core Animation keyframe animation paths.

Upvotes: 1

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