curveditor

#load "LWCs.fsx"

open System.Windows.Forms
open System.Drawing
open LWCs

let f = new Form(Text="Curve editor", TopMost=true)
f.Show()

let scrollTimer = new Timer(Interval=30)

type IumButton() as this =
  inherit LWC()

  let clickevt = new Event<System.EventArgs>()
  let clickevt1 = new Event<System.EventArgs>()

  do this.Size <- SizeF(32.f, 32.f)

  let mutable text = ""

  member this.Click = clickevt.Publish
  member this.Click1 = clickevt1.Publish

  member this.Text
    with get() = text
    and set(v) = text <- v; this.Invalidate()

  override this.OnMouseMove e = ()
  override this.OnMouseDown e = clickevt.Trigger(new System.EventArgs())
  override this.OnMouseUp e = clickevt1.Trigger(new System.EventArgs())

  override this.OnPaint e =
    let g = e.Graphics
    g.FillRectangle(Brushes.Yellow,0,0,300,300)
    g.FillEllipse(Brushes.Red, new Rectangle(0,0,int(this.Size.Width),int(this.Size.Height)))
    let sz = g.MeasureString(text, this.Parent.Font)
    g.DrawString(text, this.Parent.Font, Brushes.White, PointF((this.Size.Width - sz.Width) / 2.f, (this.Size.Height - sz.Height) / 2.f))

type NavBut=
| Up = 0
| Right = 2
| Left = 1
| Down = 3


// Lightweight controls: astrazione programmativa che imita i controlli grafici
type Editor() as this =
  inherit LWContainer()
    do
      this.SetStyle(ControlStyles.DoubleBuffer,true)
      this.SetStyle(ControlStyles.AllPaintingInWmPaint,true)
      this.SetStyle(ControlStyles.UserPaint,true)
  let pts = [| PointF(); PointF(20.f, 20.f); PointF(50.f, 50.f); PointF(50.f, 100.f) |]

  let buttons = [|
    new IumButton(Text="U",Location=PointF(32.f,0.f));
    new IumButton(Text="L",Location=PointF(0.f,32.f));
    new IumButton(Text="R",Location=PointF(64.f,32.f));
    new IumButton(Text="D",Location=PointF(32.f,64.f));
  |]

  let button (k:NavBut)=
    buttons.[int(k)]


  let handleSize = 5.f

  let mutable selected = None
  let mutable offsetDrag = PointF()

  let mutable tension = 1.f

  let mutable w2v = new Drawing2D.Matrix()
  let mutable v2w = new Drawing2D.Matrix()

  let translateW (tx, ty) =
    w2v.Translate(tx, ty)
    v2w.Translate(-tx, -ty, Drawing2D.MatrixOrder.Append)

  let rotateW a =
    w2v.Rotate a
    v2w.Rotate(-a, Drawing2D.MatrixOrder.Append)

  let rotateAtW p a =
    w2v.RotateAt(a, p)
    v2w.RotateAt(-a, p, Drawing2D.MatrixOrder.Append)

  let scaleW (sx, sy) =
    w2v.Scale(sx, sy)
    v2w.Scale(1.f/sx, 1.f/sy, Drawing2D.MatrixOrder.Append)

  let transformP (m:Drawing2D.Matrix) (p:Point) =
    let a = [| PointF(single p.X, single p.Y) |]
    m.TransformPoints(a)
    a.[0]

  let handleHitTest (p:PointF) (h:PointF) =
    let x = p.X - h.X
    let y = p.Y - h.Y
    x * x + y * y < handleSize * handleSize


  do buttons |> Seq.iter (fun b->
    b.Parent <- this
    this.LWControls.Add(b)
    )
  let mutable bUp = false
  do
    (button NavBut.Up).Click.Add(fun _ ->
        this.Cursor <- Cursors.Hand
        SendKeys.Send("{W}")
    )
    (button NavBut.Down).Click.Add(fun _ ->
        SendKeys.Send("{S}")
    )
    (button NavBut.Left).Click.Add(fun _ ->
        SendKeys.Send("{A}")
    )
    (button NavBut.Right).Click.Add(fun _ ->
        SendKeys.Send("{D}")
    )

  let scrollBy dir =
    match dir with
    | NavBut.Up -> (0.f,-10.f)
    | NavBut.Down -> (0.f,10.f)
    | NavBut.Left -> (10.f,0.f)
    | NavBut.Right -> (-10.f,0.f)

  member this.V2W = v2w

  member this.Tension
    with get () = tension
    and set (v) = tension <- v; this.Invalidate()

  override this.OnMouseDown e =
    let l = transformP v2w e.Location
    let ht = handleHitTest l
    selected <- pts |> Array.tryFindIndex ht
    match selected with
    | Some(idx) ->
      let p = pts.[idx]
      offsetDrag <- PointF(p.X - l.X, p.Y - l.Y)
    | None -> ()
    base.OnMouseDown(e)

  override this.OnMouseUp e =
    selected <- None

  override this.OnMouseMove e =
    let l = transformP v2w e.Location
    buttons |> Array.iter (fun b -> b.OnMouseMove e)
    match selected with
    | Some idx ->
      pts.[idx] <- PointF(l.X + offsetDrag.X, l.Y + offsetDrag.Y)
      this.Invalidate()
    | None -> ()

  override this.OnPaint e =
    let g = e.Graphics
    g.SmoothingMode <- Drawing2D.SmoothingMode.HighQuality
    let drawHandle (p:PointF) =
      let w = 5.f
      g.DrawEllipse(Pens.Black, p.X - w, p.Y - w, 2.f * w, 2.f * w)
    let ctx = g.Save()
    g.Transform <- w2v
    g.DrawBezier(Pens.Black, pts.[0], pts.[1], pts.[2], pts.[3])
    g.DrawLine(Pens.Red, pts.[0], pts.[1])
    g.DrawLine(Pens.Red, pts.[2], pts.[3])
    g.DrawCurve(Pens.Blue, pts, tension)
    // let (|>) x f = f x
    pts |> Array.iter drawHandle
    g.Restore(ctx)
    base.OnPaint(e)



  override this.OnKeyDown e =
    let translate (x, y) =
      let t = [| PointF(0.f, 0.f); PointF(x, y) |]
      v2w.TransformPoints(t)
      translateW(t.[1].X - t.[0].X, t.[1].Y - t.[0].Y)

    match e.KeyCode with
    | Keys.W ->
      translate(0.f,-10.f)
      this.Invalidate()
    | Keys.D ->
      translate(10.f,0.f)
      this.Invalidate()
    | Keys.A ->
      translate(-10.f,0.f)
      this.Invalidate()
    | Keys.S ->
      translate(0.f,10.f)
      this.Invalidate()
    | Keys.Q ->
      let p = transformP v2w (Point(this.Width / 2, this.Height / 2))
      rotateAtW p 10.f
      this.Invalidate()
    | Keys.E ->
      let p = transformP v2w (Point(this.Width / 2, this.Height / 2))
      rotateAtW p -10.f
      this.Invalidate()
    | Keys.Z ->
      let p = transformP v2w (Point(this.Width / 2, this.Height / 2))
      scaleW(1.1f, 1.1f)
      let p1 = transformP v2w (Point(this.Width / 2, this.Height / 2))
      translateW(p1.X - p.X, p1.Y - p.Y)
      this.Invalidate()
    | Keys.X ->
      let p = transformP v2w (Point(this.Width / 2, this.Height / 2))
      scaleW(1.f/1.1f, 1.f / 1.1f)
      let p1 = transformP v2w (Point(this.Width / 2, this.Height / 2))
      translateW(p1.X - p.X, p1.Y - p.Y)
      this.Invalidate()
    | _ -> ()




let e = new Editor(Dock=DockStyle.Fill)
f.Controls.Add(e)
e.Focus()

// <NoInMidTerm>
//let b = new Button(Text="OK")
//e.Controls.Add(b)
// </NoInMidTerm>

e.Tension <- 1.f

//e.MouseDown.Add(fun _ -> printfn "Ahi!")