Points Lines (Planes)

This implements data structures for points lines and planes(not yet) in (for now) 2D space and a few functions to play around with them. This was originally written to improve on the Convex Hull algorithm but I thought it might be a nice addition in itself. Im planning to add 3D implementations as well.

implementation

Two structs are implemented the Point2D and Line2D.

struct Point2D: {
  var x: Double
  var y: double
}

struct Line2D {
  var slope: Slope
  var offset: Double
  var direction: Direction
}

Here Slope is an enum to account for vertical lines. slope is infinite for vertical lines, offset is the x coordinate where the line crosses the line y=0. slope is finite for any other line and contains a double with the actual value of the slope.

enum Slope {
  case finite(slope: Double)
  case infinite(offset: Double)
}

Line2D also contains a Direction enum. This is introduced in order to make lines directional in order to be able to determine what is left and right of a certain line. It is .increasing if the line points in positive y direction and .decreasing if it points in the negative y direction.

Line2D's offset is the the y-coordinate where the line crosses the vertical x=0 line.

Written for the Swift Algorithm Club by Jaap Wijnen.