将CIFilter应用于CALayer [英] Applying a CIFilter to a CALayer

问题描述

因此， CI过滤器现在可在iOS 5中使用，我想将其应用于CALayer，您在Mac上的操作方式。这是我的代码：

So, CI Filters are now available in iOS 5, and I'm trying to apply one to a CALayer, the way you'd do it on Mac. Here's my code:

CALayer *myCircle = [CALayer layer];
myCircle.bounds = CGRectMake(0,0,30,30);
myCircle.position = CGPointMake(100,100);
myCircle.cornerRadius = 15;
myCircle.borderColor = [UIColor whiteColor].CGColor;
myCircle.borderWidth = 2;
myCircle.backgroundColor = [UIColor whiteColor].CGColor;

CIFilter *blurFilter = [CIFilter filterWithName:@"CIDiscBlur"];
[blurFilter setDefaults];
[blurFilter setValue:[NSNumber numberWithFloat:5.0f] forKey:@"inputRadius"];
[myCircle setFilters:[NSArray arrayWithObjects:blurFilter, nil]];

[self.view.layer addSublayer:myCircle];

我的白色圆圈绘制精美，但不应用过滤器。有什么想法吗？

My white circle draws fine, but the filter isn't applied. Any thoughts?

推荐答案

除了 CIDiskBlur iOS SDK 5.1），并且 setFilters：似乎不可用，您可以执行以下操作：

Aside from the fact that CIDiskBlur is not available (as of iOS SDK 5.1) and that setFilters: seems to be not available either you could do the following:

创建从您图层的内容输入CIImage：

Create the input CIImage from the contents of your layer:

CIImage *inputImage = [CIImage imageWithCGImage:(CGImageRef)(myCircle.contents)];`

应用您的过滤器并在CGImageRef中获得结果：

Apply your filters and get the result in an CGImageRef:

CIFilter *filter = [CIFilter filterWith...];// A filter that is available in iOS or a custom one :)
...
CIImage *outputImage = [filter outputImage];
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef cgimg = [context createCGImage:outputImage fromRect:[outputImage extent]];

最后将CGImageRef设置为图层：

Finally set the CGImageRef to the layer:

[myCircle setContents:(id)cgimg];

这应该可以工作：）

这篇关于将CIFilter应用于CALayer的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！