Programming with a DJ Controller — not vibe coding

RubyKaigi 2026

Transcript

1. Programming with a DJ Controller — not vibe coding m_seki@ninja-testing.com
2. About me Masatoshi Seki Ruby Core Committer (dRuby, Rinda, ERB) Tochigi Ruby Meetup (a.k.a toRuby) Pokémon TCG, WCS 2010 Tochigi Pref. winner Founder of ninja-testing.com （ド）忍者式 2
3. ʢυʣ೜ऀࣜ ߹ಉձࣾ೜ऀࣜ ～ ࣾ಺޲͚ߨԋͱ͔૬ஊͱ͔ ～
4. 5FYU
5. DJ Controller DJ , CDJ, PCDJ Controller - USB MIDI - Mac - DJ Software DJ2GO2 Touch I bought it, but I got bored with it after a few weeks. 買ってみたけどすぐ飽きた 5 2024 https://www.amazon.co.jp/dp/B082L3XQGR
6. 6 How to make the Groovebox How to make the Groovebox 2025 asonas's talk
7. UniMIDI I missed the talk, so I checked out his repository UniMIDI looks easy to use 7 2025
8. Agenda Programming with the DJ2GO2 Touch Using a DJ controller as a human interface device Controlling two text editors Left-hand controller Debugging Ractor applications 8 https://www.amazon.co.jp/dp/B082L3XQGR
9. MIDI Musical Instrument Digital Interface, 1981 5pin DIN → USB, Bluetooth message note on/off 9 note on ch1 C#2 80 note off ch1 C#2 control pitch...
10. DJ Controller Channel and note numbers are used to identify the button note番号と名前の対応表を見つけたが、その名前がどのボタンかわからなかった.. 10 note on ch1 C#-2 127 note off ch1 C#-2 control ... Demo
11. note number ノート番号とデバイスのコントローラーの名称の対応表を見つけたが、その名称とデ バイス上のコントローラーの関係がわからない→結局全部操作して確かめた　 11 Note On message [148, 1, 127]
12. note number ノート番号とデバイスのコントローラーの名称の対応表を見つけたが、その名称とデ バイス上のコントローラーの関係がわからない→結局全部操作して確かめた　 12 Control message value: 1 or 127 CW / CCW [176, 6, 1]
13. note number ノート番号とデバイスのコントローラーの名称の対応表を見つけたが、その名称とデ バイス上のコントローラーの関係がわからない→結局全部操作して確かめた　 13 Control message value: 0,,127 [191, 8, 60]
14. LED blinking Send a note-on message to the DJ controller, and the LED will blink Lチカ 14 note on ch1 #C-2 1 Demo
15. note number ノート番号とデバイスのコントローラーの名称の対応表を見つけたが、その名称とデ バイス上のコントローラーの関係がわからない→結局全部操作して確かめた　 15 LED Blinking!! [148, 1, 2]
16. How to get the current value Not included in standard MIDI But DJ software can query this information 初期状態（現在の状態）を知るプロトコルがない！？でもDJソフトはできてるぞ？？ どうやってるんだ 16
17. Sniffing MIDI communications DJ software startup sequence SysEx F0 00 20 7F F7 SysExを送ると、操作された時と同じメッセージを一度に送ってくる 17 LED light off
18. UniMIDI is a bit difficult to use フロー制御がどこか弱い。一度にたくさんメッセージが届いたとき、メッセージの区 切りがおかしくなったりする。それをトリートメントするライブラリを間にいれた。 18
19. MidiM::Treatment Message normalization iterator Get the messages one by one メッセージを一つずつ取り出す。Fiber使ってる 19 e = MidiM::Treatment.reader(UniMIDI::Input.first) loop do it = e.gets pp it end
20. Controlling two text editors フォーカスの移動なしに同時にスクロール 20 Demo
21. Implementation: Controlling two text editors Control two text editors 急いでqueueに積む係と、ひまになったら処理する係。全てのイベントを処理する 21 # .textbringer.rb require 'drb' DRb.start_service ro = DRbObject.new_with_uri('druby://localhost:8085') queue = Queue.new ro.connect(queue) module Textbringer class Controller def self.execute_keyboard_macro(ary) c = current c.next_tick { c.execute_keyboard_macro(ary) } end end end Thread.new do while true Textbringer::Controller.execute_keyboard_macro([queue.pop]) end end 😟
22. Implementation: Controlling two text editors このデモでは:up, :downだけ 22 class DJ2GO2Server def initialize @chan = [nil, nil] end def connect(queue) if @chan[0].nil? @chan[0] = queue elsif @chan[1].nil? @chan[1] = queue else false end end def push(data) case data when [176, 6, 1] @chan[0]&.push(:up) rescue @chan[0] = nil when [176, 6, 127] @chan[0]&.push(:down) rescue @chan[0] = nil when [177, 6, 1] @chan[1]&.push(:up) rescue @chan[1] = nil when [177, 6, 127] @chan[1]&.push(:down) rescue @chan[1] = nil end end end
23. Controlling two text editors Textbringer is highly customizable The application only accepts user input at a safe stage Because it processes all messages, it isn't very smooth 23
24. Left-hand controller Photo-editing software 滑らかに動く！と思う！ 24 Demo
25. Left-hand controller impl. Pixelmetor Pro + AppleEvent + MIDI Compress events to make them feel smoother. Two approaches to event compression 25
26. note number C ノート番号とデバイスのコントローラーの名称の対応表を見つけたが、その名称とデ バイス上のコントローラーの関係がわからない→結局全部操作して確かめた　 26 Use the latest value Use the cumulative value Two approaches to event compression
27. Implementation: Left-hand controller Driq#readpartial 主に二つのスレッドでできている 27 Driq ♪ ♪ ♪♪ ♪ ♪ ♪♪ ♪♪♪♪♪♪♪ ♪ ♪ ♪ readparital write
28. Implementation: Left-hand controller Driq#readpartial 余裕がある時に全部読む 28 Driq ♪ ♪ ♪♪ ♪ ♪ ♪♪ ♪♪♪♪♪♪♪ ♪ ♪ ♪ readparital write def update event = @queue.readpartial(@cursor, 100) @cursor = event.last.first value = {} delta = {} event.each do |k, v| case v[1] in Integer value[v[0]] = v[1] in Float delta[v[0]] ||= 0 delta[v[0]] += v[1] else end end value.each do |k, v| @app.documents.first.layers.first.color_adjustments.send(k).set(normalize(k, v)) end delta.each do |k, d| org = @app.documents.first.layers.first.color_adjustments.send(k).get v = (org + d).clamp(ColorAdjustment[k]) @app.documents.first.layers.first.color_adjustments.send(k).set(v) end end def run_updater Thread.new do while true update end end end Block until data is available, then read up to 100 items.
29. Implementation: Left-hand controller Driq#readpartial イベントを圧縮してPixelmetorを制御する 29 Driq ♪ ♪ ♪♪ ♪ ♪ ♪♪ ♪♪♪♪♪♪♪ ♪ ♪ ♪ readparital write def update event = @queue.readpartial(@cursor, 100) @cursor = event.last.first value = {} delta = {} event.each do |k, v| case v[1] in Integer value[v[0]] = v[1] in Float delta[v[0]] ||= 0 delta[v[0]] += v[1] else end end value.each do |k, v| @app.documents.first.layers.first.color_adjustments.send(k).set(normalize(k, v)) end delta.each do |k, d| org = @app.documents.first.layers.first.color_adjustments.send(k).get v = (org + d).clamp(ColorAdjustment[k]) @app.documents.first.layers.first.color_adjustments.send(k).set(v) end end def run_updater Thread.new do while true update end end end event compression controlling Pixelmetor Pro
30. Debugging Ractor applications Logging with sound Suspend and resume a Ractor with a DJ controller Listen to N-Queens music 複数ワーカーのログを読むのはごちゃごちゃしてたいへん！音にしてみればいいのでは？？ ワーカーの停止や再開をDJコントローラーで操作するよ。NQueensの音楽聴いて！ 30 Demo
31. Debugging Ractor applications 31 Demo NQueens Logger Debugger MIDI MIDI dRuby Ractor Ractor.new(rinda) do |ts| while true ts.break('nq_loop') sym, size, r1, r2 = ts.take([:nq, Integ ts.log([:nq_begin, r1, r2]) ts.write([:nq_ans, size, r1, r2, NQueen ts.log([:nq_end, r1, r2]) end end def take_a(rinda, size) found = 0 size.times.reverse_each do |r1| size.times.reverse_each do |r2| tuple = rinda.take( [:nq_ans, size, r1, r2, nil]) rinda.log(tuple) found += tuple[4] end end found end
32. Debugging Ractor applications ワーカーは音程でRactorを、マスターはドラムで結果の違いを表現してるよ！ 32 Demo NQueens Logger Debugger MIDI MIDI dRuby Ractor Ractor.new(rinda) do |ts| while true ts.break('nq_loop') sym, size, r1, r2 = ts.take([:nq, Integer, Integer, Integer]) ts.log([:nq_begin, r1, r2]) ts.write([:nq_ans, size, r1, r2, NQueen.nq2(size, r1, r2)]) ts.log([:nq_end, r1, r2]) end end def take_a(rinda, size) found = 0 size.times.reverse_each do |r1| size.times.reverse_each do |r2| tuple = rinda.take( [:nq_ans, size, r1, r2, nil]) rinda.log(tuple) found += tuple[4] end end found end
33. Agenda Programming with the DJ2GO2 Touch Using a DJ controller as a human interface device Controlling two text editors Left-hand controller Debugging Ractor applications 33 https://www.amazon.co.jp/dp/B082L3XQGR
34. TupleSpace for Ractors using Ractor::Port seki@ruby-lang.org One more thing..
35. Rinda::TupleSpace, dRuby 35 TupleSpace tuple Thread / Process
36. TupleSpace for Ractor using Ractor::Port 36 Port Port Port Ractor
37. TupleSpace4Ractor メソッド呼び出しのように書ける！べんり！ 37 Port Port Port Ractor class TupleSpace4Ractor def initialize @ractor = Ractor.new { Impl.new.main_loop } log_init end Aether = self.new end Aether.write(['hello', 'world']) Aether.take(['hello', nil])
38. TupleSpace4Ractor is DRb-aware dRubyで別プロセスからも使える！Ractorなのに！ 38 Port Port Port Ractor another process dRuby
39. Add logging and debugging support 39 Port Port Port Ractor logger / debugger dRuby
40. Debugging Ractor applications Logging with sound Suspend and resume a Ractor with a DJ controller Listen to N-Queens music 複数ワーカーのログを読むのはごちゃごちゃでたいへん！音にしてみればいいので は？？ ワーカーの停止や再開をDJコントローラーで操作するよ。NQueensの音楽聴いて！ 40 Demo
41. Debugging Ractor applications 41 Demo NQueens Logger Debugger MIDI MIDI dRuby Ractor Ractor.new(rinda) do |ts| while true ts.break('nq_loop') sym, size, r1, r2 = ts.take([:nq, Integ ts.log([:nq_begin, r1, r2]) ts.write([:nq_ans, size, r1, r2, NQueen ts.log([:nq_end, r1, r2]) end end def take_a(rinda, size) found = 0 size.times.reverse_each do |r1| size.times.reverse_each do |r2| tuple = rinda.take( [:nq_ans, size, r1, r2, nil]) rinda.log(tuple) found += tuple[4] end end found end
42. Debugging Ractor applications ワーカーは音程でRactorを、マスターはドラムで結果の違いを表現してるよ！ 42 Demo NQueens Logger Debugger MIDI MIDI dRuby Ractor Ractor.new(rinda) do |ts| while true ts.break('nq_loop') sym, size, r1, r2 = ts.take([:nq, Integer, Integer, Integer]) ts.log([:nq_begin, r1, r2]) ts.write([:nq_ans, size, r1, r2, NQueen.nq2(size, r1, r2)]) ts.log([:nq_end, r1, r2]) end end def take_a(rinda, size) found = 0 size.times.reverse_each do |r1| size.times.reverse_each do |r2| tuple = rinda.take( [:nq_ans, size, r1, r2, nil]) rinda.log(tuple) found += tuple[4] end end found end