objective-c - 使用 NSBezierPath addClip - 如何反转剪辑

Question

使用 NSBezierPath addClip 仅将绘图限制在用于裁剪的路径内。我想做相反的事情 - 只在外面画画。

- (void)drawRect:(NSRect)dirtyRect {
    NSBezierPath *dontDrawInThis = ...;

    //We want an opposite mask of [dontDrawInThis setClip];

    //Drawing comes here
}

Answer 1

这是我的解决方案:

- (void)drawRect:(NSRect)dirtyRect {
    NSBezierPath *dontDrawInThis = ...;

    // The mask is the whole bounds rect, subtracted dontDrawInThis

    NSBezierPath *clip = [NSBezierPath bezierPathWithRect:self.bounds];
    [clip appendBezierPath:dontDrawInThis.bezierPathByReversingPath];
    [clip setClip];

    //Drawing comes here
}

对于 iOS，将 NSRect 替换为 CGRect。