I have some code that uses CALayers to have bubbles flowing bottom to top. If the user touches the screen I have some code that replaces the currently running animation with one that has a toPoint where the finger touched down. When the animation switches it causes a flicker on the device (not on the simulator). Any tips on eliminating the flicker would be appreciated! Thanks.
Code for the bubbles flowing up inside the layer itself:
CABasicAnimation *animation = [CABasicAnimationanimationWithKeyPath:@"position"];
[animation setDelegate:self];
CGPoint position = [self position];
NSValue *prevVal = [NSValue valueWithCGPoint:position];
[animation setFromValue:prevVal];
CGPoint toPoint = CGPointMake(position.x,-100);
[animation setToValue:[NSValue valueWithCGPoint:toPoint]];
[animation setDuration:animationDuration];
[self addAnimation:animation forKey:@"flow"];
The code for attracting nearby bubbles to the touch point written in the super layer:
int count = [self.layer.sublayers count];
for(int i = 0; i < count ; i++) {
CALayer *layer= [self.layer.sublayers objectAtIndex:i];
CALayer *p = (CALayer*)[layer presentationLayer];
CGPoint position = [p position];
if(abs(position.x - touchPoint.x) < 100 && abs(position.y - touchPoint.y) < 100) {
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
[animation setDelegate:self];
NSValue *prevVal = [NSValue valueWithCGPoint:position];
[animation setFromValue:prevVal];
[animation setToValue:[NSValue valueWithCGPoint:touchPoint]];
[animation setDuration:2.0];
[animation setTimingFunction:[CAMediaTimingFunction
functionWithName:kCAMediaTimingFunctionEaseOut]];
[layer addAnimation:animation forKey:@"flow"];
}
}