填充从 CGPath 创建的 SKShapeNode

Question

我正在尝试创建一个基于点数组的自定义 SKShapeNode。这些点形成一个封闭的形状，最终需要填充这个形状。

这就是我到目前为止的想法，但由于某种原因笔划画得很好，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 path 出了点问题。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）了解更多详情。

Answer 2

例如你不需要为这个动作使用CGPath，你可以做这样的事情：

let points: [CGPoint] = [CGPointMake(center.x, center.y), ...] // All your points
var context: CGContextRef = UIGraphicsGetCurrentContext()

CGContextAddLines(context, points, UInt(points.count))
CGContextSetFillColorWithColor(context, UIColor.redColor().CGColor)
CGContextFillPath(context)

let shape = SKShapeNode(path: CGContextCopyPath(context))
...

填充从 CGPath 创建的 SKShapeNode

Fill SKShapeNode created from CGPath

fill

cgpath

sprite-kit

skshapenode

swift