Question

我正在使用UIBezierPath绘制弧线。我怎样才能计算出这个弧的中点。

let center = CGPoint(x: bounds.width / 2, y: bounds.height / 2)
var startValue: CGFloat = 0
var startAngle: CGFloat = 0
var endValue: CGFloat = 0
var endAngle: CGFloat = 0

startAngle = (startValue * 2 * CGFloat(M_PI)) - CGFloat(M_PI_2)
endValue = startValue + 0.20
endAngle = (endValue * 2 * CGFloat(M_PI)) -CGFloat(M_PI_2)

let path = UIBezierPath()
path.moveToPoint(center)
path.addArcWithCenter(center, radius: radius.outer, startAngle: startAngle, endAngle: endAngle, clockwise: true)

path.fill()
path.stroke()

Answer 1

midPoint角度将是startAngle和endAngle的平均值。这会根据center点和radius.outer：

计算点数

let midPointAngle = (startAngle + endAngle) / 2.0
let midPoint = CGPoint(x: center.x + radius.outer * cos(midPointAngle), y: center.y - radius.outer * sin(midPointAngle))

如何使用UIBezierPath路径ios或swift计算圆弧绘制的中间点

1 个答案: