Question

我正在使用CAKeyframeAnimation课程。我有两个图像沿着它们的曲线路径在屏幕上移动，我遇到了以下问题：偶尔当图像彼此接近时，其中一个（从来没有另一个）从一个或两个消失了屏幕。只有当它们接近时它才会发生，但当它们的帧相互作用时却不会发生。你有经历过这样的经历吗？可能是什么原因造成的？如果需要，我会显示我的代码。非常感谢。

这是第一张图片移动的方式：

- (void)lizardJumps
{
   if (isAnimation)
    return;

CGRect frame = [[stageFrames objectAtIndex:isLizardOnLeftRock ? 0 : 2] CGRectValue];
CGPoint start_point = CGPointMake(frame.origin.x, frame.origin.y);

CGRect frame2 = [[stageFrames objectAtIndex:isLizardOnLeftRock ? 2 : 0] CGRectValue];
CGPoint finish_point = CGPointMake(frame2.origin.x + 15, frame2.origin.y + 20);

CAKeyframeAnimation *lizardJumpAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
CGMutablePathRef curvedPath = CGPathCreateMutable();
CGPathMoveToPoint(curvedPath, NULL, start_point.x, start_point.y);
CGPathAddQuadCurveToPoint(curvedPath, NULL, 240, 0, finish_point.x, finish_point.y);
lizardJumpAnimation.path                = curvedPath;
lizardJumpAnimation.duration            = jump_duration;
lizardJumpAnimation.fillMode            = kCAFillModeForwards;
lizardJumpAnimation.removedOnCompletion = NO;
lizardJumpAnimation.timingFunction      = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];  
lizardJumpAnimation.delegate            = self;
[lizard.layer addAnimation:lizardJumpAnimation forKey:@"jumpAnimation"];

CGPathRelease(curvedPath);

[[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:jump_duration]];
lizard.transform = CGAffineTransformIdentity;

if (isLizardOnLeftRock)
    lizard.transform = CGAffineTransformMakeScale(-1.0, 1.0);
else
    lizard.transform = CGAffineTransformMakeScale(1.0, 1.0);

isLizardOnLeftRock = !isLizardOnLeftRock;
 }

`

 - (void)animationTiming:(NSTimer *)t
  {
   CALayer *testLayer    = lizard.layer.presentationLayer;
  CALayer *testBugLayer = bug.layer.presentationLayer;

   BOOL intersects = CGRectIntersectsRect(testBugLayer.frame, testLayer.frame);
   if (intersects)
    NSLog(@"intersects");
 }

  - (void)animationDidStart:(CAAnimation *)anim
 {
  isAnimation = YES;

   timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(animationTiming:) userInfo:nil repeats:YES];
  }

  - (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
 {
isAnimation = NO;
   [timer invalidate];
}

`

这是另一个：

- (void)bugFlies
{
[bug setHidden:NO];

CGPoint start_point = CGPointMake(0, 170);
CGPoint finish_point = CGPointMake(170, 170);

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

for (int i = 0; i < 3; i++)
{
  CGMutablePathRef curvedPath = CGPathCreateMutable();

  CGPathMoveToPoint(curvedPath, NULL, start_point.x, start_point.y);
  CGPathAddCurveToPoint(curvedPath, NULL, start_point.x + 50, finish_point.y + 100, start_point.x + 50 , finish_point.y - 100, finish_point.x, finish_point.y); 
  bugFlightAnimation.path                = curvedPath;
  bugFlightAnimation.duration            = flight_duration;
  bugFlightAnimation.removedOnCompletion = NO;

  [bug.layer addAnimation:bugFlightAnimation forKey:@"bug_flight"];
    start_point = finish_point;
    finish_point.x += 170; 

  [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:flight_duration]];
     CGPathRelease(curvedPath);
}
[bug setHidden:YES];

}

核心动画 - 动画图像的移动使另一个消失

0 个答案: