遮罩、模糊效果和动画

来源：互联网发布：搜狗上的动态壁纸软件编辑：程序博客网时间：2024/05/16 17:08

Masks，Blurs and Animation

一.遮罩(Mask)
裁剪将绘图限定在路径的区域内，如下面示例：

- (UIImage *)getImage:(CGSize)targetSize{    UIGraphicsBeginImageContextWithOptions(targetSize, NO, 0.0);    CGRect targetRect =[self SizeMakeRect:targetSize];    CGRect inset = [self RectInsetByPercent:targetRect percent:0.15];    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:inset];    UIBezierPath *inner = [UIBezierPath bezierPathWithOvalInRect:[self RectInsetByPercent:inset percent:0.4]];    path.usesEvenOddFillRule = YES;    [path appendPath:inner];    [path addClip];    UIImage *cat = [UIImage imageNamed:@"cat.jpg"];    [cat drawInRect:targetRect];    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    return image;}- (CGRect) RectInsetByPercent :(CGRect)rect percent:(CGFloat)percent{    CGFloat wInset = rect.size.width * percent /2.0f;    CGFloat hInset = rect.size.height * percent / 2.0f;    return CGRectInset(rect, wInset, hInset);}- (CGRect)SizeMakeRect:(CGSize)size{    return (CGRect){.size = size};}

效果如下：

你实现这样的效果可以通过Quartz或者UIKit，例如，你可以调用CGContextClip()来调整上下文来裁剪当前的路径或者向UIBezierPath实例发送addClip消息。

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