module Pov = Povray
module PovTextures = Pov.Textures
module PovInc = Pov.Inc_file
module PovColor = Pov.Color
module PovDesc = Pov.Desc

let () = Random.self_init ()

let cs1 = [| PovColor.Green; PovColor.Yellow; |]
let cs2 = [| PovColor.Red; PovColor.Blue; |]
let cs3 = [| PovColor.Cyan; PovColor.Magenta; |]

let cs =
  match Random.int 3 with
  | 0 -> cs1 | 1 -> cs2 | _ -> cs3


let get_color1 () = PovColor.Green
let get_color2 () =
  let n = Array.length cs in
  cs.(Random.int n)

let get_color3 () =
  let r = Random.float 1.0 in
  let g = Random.float 1.0 in
  let b = Random.float 1.0 in
  PovColor.RGB(r, g, b)

let get_color =
  match Random.int 3 with
  | 0 -> get_color1
  | 1 -> get_color2
  | _ -> get_color3

let rand_num a b =
  a + (Random.int (b - a + 1))


let () =
  let inc = PovInc.to_string PovInc.Colors in
  let bg_color = PovColor.RGB(0.0, 0.1, 0.2) in
  let cam_loc, look_at = (0, 2, -3), (0, 1, 2) in

  let light_loc = (2, 4, -3) in
  let light_color = PovColor.RGB(0.4, 0.5, 0.6) in

  let new_sphere () =
    let color = get_color () in
    let x = (float (rand_num 0 20)) /. 10.0 in
    let y = (float (rand_num 0 20)) /. 10.0 in
    let z = (float (rand_num 0 20)) /. 10.0 in
    let r = (float (rand_num 2  6)) /. 10.0 in
    let sphere_center = (x, y, z) in
    let sphere_radius = r in
    let sphere_tex = Pov.get_texture ~color () in

    Pov.Sphere (sphere_radius, sphere_center, sphere_tex);
  in

  let desc = [
    Pov.Include inc;
    Pov.Background bg_color;
    Pov.Camera (cam_loc, look_at);
    Pov.Light_source (light_loc, light_color);
    (* ... *)
  ] in

  let add_elems n desc =
    let rec aux i acc =
      if i <= 0 then acc else
      let this = new_sphere () in
      aux (pred i) (this::acc)
    in
    let rs = aux n [] in
    desc @ rs
  in
  let desc = add_elems 22 desc in

  let scene = PovDesc.to_scene desc in

  Pov.print_scene scene;
;;