swift - 填充从 CGPath 创建的 SKShapeNode

Question

我正在尝试基于点数组创建自定义 SKShapeNode。这些点形成一个封闭的形状，最终需要填充该形状。

这是我到目前为止所想到的，但由于某种原因，笔画画得很好，但形状仍然是空的。我错过了什么？

override func didMoveToView(view: SKView)
{
    let center = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
    let path = CGPathCreateMutable()


    CGPathMoveToPoint(path, nil, center.x, center.y)
    CGPathAddLineToPoint(path, nil, center.x + 50, center.y + 50)

    CGPathMoveToPoint(path, nil, center.x + 50, center.y + 50)
    CGPathAddLineToPoint(path, nil, center.x - 50, center.y + 50)

    CGPathMoveToPoint(path, nil, center.x - 50, center.y + 50)
    CGPathAddLineToPoint(path, nil, center.x - 50, center.y - 50)

    CGPathMoveToPoint(path, nil, center.x - 50, center.y - 50)
    CGPathAddLineToPoint(path, nil, center.x, center.y)

    CGPathCloseSubpath(path)

    let shape = SKShapeNode(path: path)
    shape.strokeColor = SKColor.blueColor()
    shape.fillColor = SKColor.redColor()
    self.addChild(shape)
}

Answer 1

您的路径有问题。您通常会调用 CGPathMoveToPoint 来设置路径的起点，然后调用一系列 CGPathAdd* 来将线段添加到路径中。尝试像这样创建它:

let path = CGPathCreateMutable()         
CGPathMoveToPoint(path, nil, center.x, center.y)
CGPathAddLineToPoint(path, nil, center.x + 50, center.y + 50)
CGPathAddLineToPoint(path, nil, center.x - 50, center.y + 50)
CGPathAddLineToPoint(path, nil, center.x - 50, center.y - 50)
CGPathCloseSubpath(path)

阅读CGPath Reference (搜索CGPathMoveToPoint)了解更多详细信息。