Exrayを使ってElixirで円を描画してみる

Elixirで手軽に描画する方法があります
それはExrayを使うことです
Exrayはraylibを参照してます

いま時点ではExrayは2Dしか動かないです

検証済み環境

• Ubuntu 22.04(実機)
• Windows 11 + WSL2(Ubuntu 22.04)

※macOSは動かなかった

作成方法

$ mix new hoge
$ cd hoge

を見ながら

exrayを追加

mix.exs

# 省略
  defp deps do
    [
+     {:exray, "~> 0.6.0"}
    ]
  end
# 省略

ライブラリ取得＆コンパイル

$ mix deps.get
$ mix compile.exray

ソースを書く

hexdocsのソースに円を追加しただけです

のソースをコピーして修正

lib/hoge.ex

- defmodule SuperCoolGame do
+ defmodule Hoge do

  # We import Exray.Core.Window, like we did in IEX.
  import Exray.Core.Window
  # But, we also import Exray.Core.Drawing, to have access to begin_draw() and end_draw() calls.
  # This is to poll for window_should_close?() events, as without end_draw() no inputs will be polled at all.
  import Exray.Core.Drawing
  # We also need to import Exray.Core.Timing in order to set our FPS. This is VERY important.
  import Exray.Core.Timing
+ alias Exray.Utils.Colors
+ alias Exray.Shapes.Basic


  def run(width \\ 200, height \\ 200, title \\ "Hello World!") do
    init_window(width, height, title)
    set_target_fps(60) # <-- SUPER important! Call this just after you init_window, or segfaults are gonna happen a lot.
    main_loop()

    # As another layer of safety, if for some reason our window *didn't* close, we can do it here in this check.
    if window_should_close?() do
      close_window()
    end

    :ok # :ok, because we're :ok :)
  end

  defp main_loop() do

    # Stay out of update and draw unless our window is ready to update and draw.
    unless window_is_ready?(), do: main_loop()

    # If at any point we press Raylib's default "Quit Application" key, (ESCAPE), stop looping and exit.
    unless window_should_close?() do
      update()
      draw()
      main_loop()
    end
  end

  defp update() do
    # Nothing yet!
  end

  defp draw() do
    # Before drawing, we'll clear the background with the Exray.Utils.Colors.black function result- Which is %Exray.Structs.Color{r: 0, g: 0, b: 0, a: 255}.
-   clear_background(Exray.Utils.Colors.black())
+   clear_background(Colors.white)
    begin_drawing()

    # Nothing yet!
+   Basic.draw_circle(100, 100, 50.0, Colors.red)

    end_drawing()
  end

end

実行

$ mix run --eval "Hoge.run()"

基本的な描画

を参照してください

今回はdraw_circleを使いました

色はこちらに定義されてます

今回のソース

おわり