CAShapeLayer填充另一个CAShapeLayer作为掩码

Question

我的问题是关于用另一个CAShapeLayer填充动画一个CAShapeLayer。所以，我写了一些几乎达到我目标的代码。

我创建了一个基础层并用另一个填充它。代码如下：

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    _shapeLayer = [CAShapeLayer layer];
    [self drawBackgroundLayer];
}
// my main/backgound layer
- (void)drawBackgroundLayer {
    _shapeLayer.frame = CGRectMake(0, 0, 250, 250);
    _shapeLayer.lineWidth = 3;
    _shapeLayer.strokeColor = [UIColor blackColor].CGColor;
    _shapeLayer.fillColor = UIColor.whiteColor.CGColor;
    _shapeLayer.path = [UIBezierPath bezierPathWithRect:_shapeLayer.bounds].CGPath;

    [self.view.layer addSublayer:_shapeLayer];

    [self createCircleLayer];

}

创建带圆圈的遮罩层以进行填充：

- (void)createCircleLayer {

    _shapeLayer.fillColor = UIColor.greenColor.CGColor;

    CAShapeLayer *layer = [CAShapeLayer layer];

    CGFloat radius = _shapeLayer.bounds.size.width*sqrt(2)/2;

    layer.bounds = CGRectMake(0, 0, 2*radius, 2*radius);

    layer.position = CGPointMake(_shapeLayer.bounds.size.width/2, _shapeLayer.bounds.size.height/2);

    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:layer.bounds cornerRadius:radius];
    layer.path = path.CGPath;

    layer.transform = CATransform3DMakeScale(0.1, 0.1, 1);
    _shapeLayer.mask = layer;

}

//我们的结果是下一个]

所以，让我们动画吧。我只是转换图层来填充整个“_shapeLayer”。

- (void)animateMaskLayer:(CAShapeLayer *)maskLayer {

    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];

    animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeScale(1, 1, 1.0)];
    animation.duration = 1;
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeForwards;
    [newLayer addAnimation:animation forKey:@"transform"];
}

现在，我想对这个绿色层做同样的事情（用红色填充它）。但是当我使用面具时，我有红色圆圈和白色背景显然是什么。我的目标是拥有红色圆圈和绿色背景。像正常填充另一种颜色。通过使用逆掩码也无济于事。所以，我只是不知道如何做到这一点。

如果你建议使用：

[_shapeLayer addSublayer:layer];

它不会起作用，因为不仅有方形而且不同的路径，并且clipToBounds不是一个选项。

感谢您的任何帮助！

Answer 1

所以，解决方案很简单。我只使用两层和一个遮罩层。

第一层：红色层我想填充绿色层;

- (void)drawBackgroundLayer {
    _shapeLayer.frame = CGRectMake(20, 20, 250, 250);
    _shapeLayer.lineWidth = 3;
    _shapeLayer.strokeColor = [UIColor blackColor].CGColor;
    _shapeLayer.lineWidth = 3;
    _shapeLayer.fillColor = UIColor.redColor.CGColor;
    _shapeLayer.path = [UIBezierPath bezierPathWithRect:_shapeLayer.bounds].CGPath;

    [self.view.layer addSublayer:_shapeLayer];
    [self drawUpperLayer];
}

第二层：我用于填充的绿色层。

- (void)drawUpperLayer {

    _upperLayer = [CAShapeLayer layer];
    _upperLayer.frame = _shapeLayer.frame;
    _upperLayer.lineWidth = 3;
    _upperLayer.strokeColor = [UIColor blackColor].CGColor;
    _upperLayer.fillColor = UIColor.greenColor.CGColor;
    _upperLayer.path = [UIBezierPath bezierPathWithRect:_shapeLayer.bounds].CGPath;

    [_shapeLayer.superlayer addSublayer:_upperLayer];

}

掩模层：

- (void)createMaskLayer {

    CAShapeLayer *layer = [CAShapeLayer layer];
    CGFloat radius = _upperLayer.bounds.size.width*sqrt(2)/2;

    layer.bounds = CGRectMake(0, 0, 2*radius, 2*radius);
    layer.fillColor = UIColor.blackColor.CGColor;

    layer.position = CGPointMake(_upperLayer.bounds.size.width/2, _upperLayer.bounds.size.height/2);

    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:layer.bounds cornerRadius:radius];
    layer.path = path.CGPath;

    layer.transform = CATransform3DMakeScale(0.1, 0.1, 1);

    _upperLayer.mask = layer;
}

动画遮罩层：

- (void)animateMaskLayer:(CAShapeLayer *)maskLayer {
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
    animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeScale(1, 1, 1.0)];
    animation.duration = 2;
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeForwards;
    [maskLayer addAnimation:animation forKey:@"transform"];
}

因此，结果动画：