YZPolygonHelper 0.0.3

You want to add pod 'YZPolygonHelper', '~> 0.0' similar to the following to your Podfile:

target 'MyApp' do
  pod 'YZPolygonHelper', '~> 0.0'
end

Then run a pod install inside your terminal, or from CocoaPods.app.

Alternatively to give it a test run, run the command:

pod try YZPolygonHelper

YZPolygonHelper 0.0.3

By
Yichi Zhang

A few class methods to help working with polygons; such as: find the center (centroid) of a polygon; test if a point is with inside a polygon or not.

Examples

    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
        }
    )

Acknowledgements/ Copyright information

'Find Centroid'

Algorithm by Paul Bourke http://paulbourke.net/geometry/polygonmesh/

Adapted from the C code provided by 'squeamish ossifrage' http://stackoverflow.com/users/1679849/squeamish-ossifrage

From page http://stackoverflow.com/questions/19766485/how-to-calculate-centroid-of-polygon-in-c