Orologio analogico

AnalogClock.fsx

open System.Windows.Forms
open System.Drawing

let f = new Form(TopMost=true, Text="Clock", Size=Size(400, 400))
f.Show()

let pi = System.Math.PI

type AnalogClock() =
  inherit UserControl()
  
  do base.SetStyle(ControlStyles.OptimizedDoubleBuffer ||| ControlStyles.AllPaintingInWmPaint, true)
  
  let mutable current = System.DateTime.Now
  let mutable scala = 100

  member this.DateTime 
    with get() = current
    and set(v) = current <- v; this.Invalidate()

  member this.CambiaScala
    with get() = scala
    and set(v) = scala <- v

  override this.OnPaint e =
      let g = e.Graphics
      g.SmoothingMode <- Drawing2D.SmoothingMode.HighQuality
      let m = min this.Width this.Height 
      let w, h = m, m
      let c = Point(50, 50)
      let cf = PointF(50.f, 50.f)

      let newscala = single scala / 100.f
      g.ScaleTransform(newscala, newscala)

      let da = pi / 6.

      let transform = g.Transform

      g.DrawEllipse(Pens.Black, 1, 1, 98, 98)

      for i = 1 to 12 do
        g.DrawLine(Pens.Black, c.X + 50 - 5, c.Y, c.X + 49, c.Y)
        let t = g.Transform
        t.RotateAt(30.f, cf)
        g.Transform <- t

      g.Transform <- transform

      let drawRotatedLine(p, a, x1:int, y1:int, x2:int, y2:int) =
        let t = g.Transform
        t.RotateAt(a, cf)
        g.Transform <- t
        g.DrawLine(p, x1, y1, x2, y2)
        g.Transform <- transform
    
      let sa = single((float current.Second) * (180. / 30.) - 180. / 2.)
      let msa = single((float current.Millisecond) * ( 180. / 30. ) / 1000. )
      drawRotatedLine(Pens.Black, sa + msa, c.X - 5, c.Y, c.X + 49, c.Y)

      use mp = new Pen(Brushes.Black, Width=2.f)
      let sm = single((float current.Minute) * (180. / 30.) - 180. / 2.)
      drawRotatedLine(mp, sm, c.X - 5, c.Y, c.X + 40 , c.Y)

      use hp = new Pen(Brushes.Black, Width=3.f)
      let sp = single((float current.Hour) * (180. / 6.) - 180. / 2.)
      drawRotatedLine(hp, sp, c.X - 5, c.Y, c.X + 30, c.Y)

let init (c:AnalogClock) =
    c.Size <- f.ClientSize
    c.CambiaScala <- min f.ClientSize.Height f.ClientSize.Width

let c = new AnalogClock(Location=Point(0, 0))
init(c)
f.Controls.Add(c)

f.ResizeEnd.Add(fun e ->
  init(c)
)

let t = new Timer(Interval=25)
t.Tick.Add(fun _ -> 
  f.Invalidate()
  c.DateTime <- System.DateTime.Now
)
t.Start()