YZPolygonHelper 0.0.3
- 由
- Yichi Zhang
一些帮助处理多边形的类方法，例如：找到多边形的中心（质心）；测试一个点是否在多边形内部。
示例
func updateCentroid(){
self.centroidPointView.center =
YZPolygonHelper.findCentroidForNumberOfPoints(
self.controlPointViewsArray.count,
xAtIndexBlock: { (UInt idx) -> CGFloat in
let view:ControlPointView = self.controlPointViewsArray[idx]
return view.center.x
},
yAtIndexBlock:{ (UInt idx) -> CGFloat in
let view:ControlPointView = self.controlPointViewsArray[idx]
return view.center.y
}
)
} var result:Bool =
YZPolygonHelper.isPointContained(
point,
inNumberOfPoints: pointsArray.count,
xAtIndexBlock: { (idx:Int) -> CGFloat in
return pointsArray[idx].x
},
yAtIndexBlock: { (idx:Int) -> CGFloat in
return pointsArray[idx].y
}
)致谢/版权信息
'找到质心'
算法由 Paul Bourke 提供，网址为 http://paulbourke.net/geometry/polygonmesh/
根据 'squeamish ossifrage' 提供的 C 代码修改，网址为 http://stackoverflow.com/users/1679849/squeamish-ossifrage
从页面 http://stackoverflow.com/questions/19766485/how-to-calculate-centroid-of-polygon-in-c 中获取