CALayer 的抗锯齿对角边缘

发布于 2024-11-13 02:05:38 字数 1131 浏览 5 评论 0原文

当我使用 CATransform3DRotate 设置 CALayer 的变换属性时，图层会正确旋转。然而，图层的边缘是锯齿状的并且没有抗锯齿。我读过关于这个主题的几篇文章：

我尝试通过在对角线图层上设置以下属性来采纳他们的建议，

CALayer* layer = myView.layer;
layer.shadowOpacity = 0.01;
layer.edgeAntialiasingMask = kCALayerTopEdge | kCALayerBottomEdge | kCALayerRightEdge | kCALayerLeftEdge;
layer.borderWidth = 1.0;
layer.borderColor = [UIColor clearColor].CGColor;
layer.backgroundColor = [UIColor greenColor].CGColor;

我还重写了对角线图层的 drawLayer:inContext: 方法以确保抗锯齿：

-(void)drawLayer:(CALayer*)layer inContext:(CGContextRef)context
{
    CGContextSetAllowsAntialiasing(context, true);
    CGContextSetShouldAntialias(context, true);
    CGContextSetFillColorWithColor(context, [UIColor greenColor].CGColor);
    CGContextFillRect(context, self.bounds);
}

我缺少什么？

原文

When I set the transform property of my CALayer with a CATransform3DRotate, the layer is properly rotated. However, the edges of the layer are jagged and not anti-aliased. I've read a couple posts on the subject:

iPhone: CALayer + rotate in 3D + antialias?

iPhone - Jagged Edges when applying perspective to CALayer

I've tried to incorporate their advice by setting the following properties on my diagonal layer

CALayer* layer = myView.layer;
layer.shadowOpacity = 0.01;
layer.edgeAntialiasingMask = kCALayerTopEdge | kCALayerBottomEdge | kCALayerRightEdge | kCALayerLeftEdge;
layer.borderWidth = 1.0;
layer.borderColor = [UIColor clearColor].CGColor;
layer.backgroundColor = [UIColor greenColor].CGColor;

I've also overridden the drawLayer:inContext: method of my diagonal layer to ensure anti-aliasing:

-(void)drawLayer:(CALayer*)layer inContext:(CGContextRef)context
{
    CGContextSetAllowsAntialiasing(context, true);
    CGContextSetShouldAntialias(context, true);
    CGContextSetFillColorWithColor(context, [UIColor greenColor].CGColor);
    CGContextFillRect(context, self.bounds);
}

What am I missing?

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清风疏影 2024-11-20 02:05:38

从 iOS7 开始，现在终于可以在每层基础上实现这一点，并且没有任何丑陋的黑客（例如透明像素）或解决方法（例如光栅化）：

layer.allowsEdgeAntialiasing = YES;

有趣的是，官方并未涵盖这一点CALayer有文档说明，但绝对是一个公共API。请参阅 iOS7 API 差异和 Peter Steinberger 关于 iOS7 中的隐藏宝石和解决方法。

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温柔戏命师 2024-11-20 02:05:38

我刚刚为此发表了一篇关于图像的文章。也许会有帮助。

我发现了一些有用的技巧，但仅设置边框并没有达到我的预期。您可以做的是设置一些设置来帮助插值、光栅化和光栅化比例。

看看这段代码中的内容是否有帮助：

    UIImage * img =[UIImage imageWithData:[NSData dataWithContentsOfFile:[[[NSBundle mainBundle ] resourcePath ] stringByAppendingPathComponent:@"AliasImage.png" ] ] ];
CGRect imageRect = CGRectMake( 0 , 0 , img.size.width + 4 , img.size.height + 4 );
UIGraphicsBeginImageContext( imageRect.size );
[img drawInRect:CGRectMake( imageRect.origin.x + 2 , imageRect.origin.y + 2 , imageRect.size.width - 4 , imageRect.size.height - 4 ) ];
CGContextSetInterpolationQuality( UIGraphicsGetCurrentContext() , kCGInterpolationHigh );
img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[aliasImage setImage:img ];

aliasImage.transform = CGAffineTransformScale(aliasImage.transform , 0.45 , 0.45 );
aliasImage.layer.shouldRasterize = YES;
aliasImage.layer.rasterizationScale = 0.45;
aliasImage.layer.edgeAntialiasingMask = kCALayerLeftEdge | kCALayerRightEdge | kCALayerBottomEdge | kCALayerTopEdge;
aliasImage.clipsToBounds = NO;
aliasImage.layer.masksToBounds = NO;

我在此处发布了一些示例

I just did a post on this for images. Maybe it will help.

I found a few tricks that help and setting just a border did not do what I thought it would. What you can do is set a few settings to help with interpolation, rasterizing, and the rasterisationScale.

See if something from this code helps:

    UIImage * img =[UIImage imageWithData:[NSData dataWithContentsOfFile:[[[NSBundle mainBundle ] resourcePath ] stringByAppendingPathComponent:@"AliasImage.png" ] ] ];
CGRect imageRect = CGRectMake( 0 , 0 , img.size.width + 4 , img.size.height + 4 );
UIGraphicsBeginImageContext( imageRect.size );
[img drawInRect:CGRectMake( imageRect.origin.x + 2 , imageRect.origin.y + 2 , imageRect.size.width - 4 , imageRect.size.height - 4 ) ];
CGContextSetInterpolationQuality( UIGraphicsGetCurrentContext() , kCGInterpolationHigh );
img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[aliasImage setImage:img ];

aliasImage.transform = CGAffineTransformScale(aliasImage.transform , 0.45 , 0.45 );
aliasImage.layer.shouldRasterize = YES;
aliasImage.layer.rasterizationScale = 0.45;
aliasImage.layer.edgeAntialiasingMask = kCALayerLeftEdge | kCALayerRightEdge | kCALayerBottomEdge | kCALayerTopEdge;
aliasImage.clipsToBounds = NO;
aliasImage.layer.masksToBounds = NO;

I have some examples posted here

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