獲取區和UIBezierPath IOS

Question

的周長我有一個UIBezierPath：

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

，當它在該方法中感動：

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

我得到一分。當我檢索2分我想要得到我感動的UIBezierPath的片段（區域或周長）時，我該如何實現這一點？

Answer 1

使用CGPathGetBoundingBox獲得路徑的邊界框，即最小矩形路徑封閉所有點：

CGRect pathBounds = CGPathGetBoundingBox(tracePath.CGPath) 

Answer 2

CGPathGetBoundingBox不考慮畫筆的大小和將削減邊界。

-(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]]; 
}