获取UIBezierPath IOS的​​区域和周长

Question

我有一个UIBezierPath：

    CGPathRef tapTargetPath = CGPathCreateCopyByStrokingPath(tracePath.CGPath, NULL, marginError, tracePath.lineCapStyle, tracePath.lineJoinStyle, tracePath.miterLimit);
    UIBezierPath *tracePath = [UIBezierPath bezierPathWithCGPath:tapTargetPath];

在方法中触及时：

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event

我明白了。当我获取2个点时，我想获得我正在触摸的UIBezierPath的片段（区域或周长），我该如何实现？

Answer 1

CGPathGetBoundingBox没有考虑画笔大小，会切割边框。

-(CGRect) getBiggerFrameFromPath:(CGPathRef) path{
    CGRect tmpFrame = CGPathGetBoundingBox(path);
    CGRect biggerFrame = CGRectMake(tmpFrame.origin.x-self.brushSize/2,
                                    tmpFrame.origin.y-self.brushSize/2,
                                    tmpFrame.size.width+self.brushSize,
                                    tmpFrame.size.height+self.brushSize);
    return biggerFrame;
}

-(void) refreshDisplayWithPath:(CGPathRef) path{
    [self setNeedsDisplayInRect:[self getBiggerFrameFromPath:path]];
}

Answer 2

使用CGPathGetBoundingBox获取路径的边界框，即包围路径中所有点的最小矩形：

CGRect pathBounds = CGPathGetBoundingBox(tracePath.CGPath)