// This snippet has been shared from Fun3D web site.
// You can run it in your web browser at: www.fun3d.net!
let countOfDisks = 10
 
let initialState = [for x in 1..countOfDisks do yield x], List.empty, List.empty 
 
let bottDiskSize = 4.
let cylHeight = 4.0
let diskSize size = size * bottDiskSize / float(countOfDisks)
let diskHeight = cylHeight / float(countOfDisks)
let diskPosition pos = pos * diskHeight
let cyl = 
    Fun.cylinder
    |> Fun.scale (0.2, cylHeight, 0.2)
    |> Fun.move (0.0, cylHeight / 2., 0.0 ) 
    |> Fun.color 0xffff00
 
let bottDisk = 
//    Fun.empty
    Fun.cylinder
    |> Fun.scale (bottDiskSize, 0.1, bottDiskSize)
    |> Fun.move (0.0, -0.05, 0.0) 
    |> Fun.color 0xff00ff
 
let disk pos size = 
    let size = float(size)
    Fun.cylinder
    |> Fun.scale (diskSize size, diskHeight, diskSize size)
    |> Fun.move (0.0, diskPosition pos + (diskHeight/2.), 0.0) 
 
let tower towerState position =  
    towerState
    |> List.rev
    |> List.mapi (fun i v -> float(i),v)
    |> List.fold (fun s (pos,size) -> s $ disk pos size ) (bottDisk $ cyl) 
    |> Fun.move (position, 0.0, 0.0)
 
let  renderState state =
     let tower1,tower2, tower3 = state
     let towers = tower tower1 (-bottDiskSize - 0.1) $
                  tower tower2 0. $
                  tower tower3 (bottDiskSize + 0.1)
     towers |> Fun.move (0.0, -cylHeight/2., 0.0)
 
renderState initialState