dreamstack/examples/step-sequencer.ds

-- DreamStack Step Sequencer
-- Collaborative beat grid: two tabs, same pads, real-time sync
--
-- Run:
--   Tab 1: cargo run -p ds-stream                           (relay)
--   Tab 2: dreamstack dev examples/step-sequencer.ds        (player 1)
--   Tab 3: dreamstack dev examples/step-sequencer.ds --port 3001 (player 2)

let bpm = 120
let step = 0
let playing = 1

-- 4 instruments × 16 steps = 64 pads
let kick  = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
let snare = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
let hihat = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
let bass  = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

-- Playhead advances every beat (8th note = 60000 / bpm / 2)
every (60000 / bpm / 2) -> step = if playing then (step + 1) % 16 else step

-- ── Audio triggers ──
-- On each step, play the sound if the pad is active
every (60000 / bpm / 2) -> play_tone(if playing then (if kick[step] then 60 else 0) else 0, 100, "sine")
every (60000 / bpm / 2) -> play_noise(if playing then (if snare[step] then 100 else 0) else 0, 0.4)
every (60000 / bpm / 2) -> play_noise(if playing then (if hihat[step] then 40 else 0) else 0, 0.15)
every (60000 / bpm / 2) -> play_tone(if playing then (if bass[step] then 110 else 0) else 0, 120, "triangle")

-- Stream for multiplayer collaboration
stream beats on "ws://localhost:9100/peer/beats" {
  mode: signal,
  output: bpm, step, playing, kick, snare, hihat, bass
}

view beats =
  column [
    text "🎹 DreamStack Beats" { variant: "title" }
    text "Collaborative step sequencer — synced via bitstream relay" { variant: "subtitle" }

    -- Transport controls
    row [
      button (if playing then "⏸ Pause" else "▶ Play") {
        click: playing = if playing then 0 else 1,
        variant: "primary"
      }
      button "⏮ Reset" {
        click: step = 0,
        variant: "ghost"
      }
      text "BPM: {bpm}" { variant: "caption" }
      button "−" { click: bpm = if bpm > 40 then bpm - 10 else bpm, variant: "secondary" }
      button "+" { click: bpm = if bpm < 300 then bpm + 10 else bpm, variant: "secondary" }
    ]

    -- Playhead indicator
    row [
      text "     " { variant: "muted" }
      for i in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15] ->
        text (if i == step then "▼" else "·") { variant: "muted" }
    ]

    -- Kick row
    row [
      text "KICK " { variant: "caption" }
      for i in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15] ->
        button (if kick[i] then "●" else "○") {
          click: kick[i] = if kick[i] then 0 else 1,
          variant: (if kick[i] then "primary" else "secondary")
        }
    ]

    -- Snare row
    row [
      text "SNRE " { variant: "caption" }
      for i in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15] ->
        button (if snare[i] then "●" else "○") {
          click: snare[i] = if snare[i] then 0 else 1,
          variant: (if snare[i] then "primary" else "secondary")
        }
    ]

    -- HiHat row
    row [
      text "HHAT " { variant: "caption" }
      for i in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15] ->
        button (if hihat[i] then "●" else "○") {
          click: hihat[i] = if hihat[i] then 0 else 1,
          variant: (if hihat[i] then "primary" else "secondary")
        }
    ]

    -- Bass row
    row [
      text "BASS " { variant: "caption" }
      for i in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15] ->
        button (if bass[i] then "●" else "○") {
          click: bass[i] = if bass[i] then 0 else 1,
          variant: (if bass[i] then "primary" else "secondary")
        }
    ]

    -- Presets
    text "Presets" { variant: "caption" }
    row [
      button "Four on the Floor" {
        click: kick[0] = 1; kick[4] = 1; kick[8] = 1; kick[12] = 1; snare[4] = 1; snare[12] = 1; hihat[0] = 1; hihat[2] = 1; hihat[4] = 1; hihat[6] = 1; hihat[8] = 1; hihat[10] = 1; hihat[12] = 1; hihat[14] = 1,
        variant: "ghost"
      }
      button "Clear All" {
        click: kick[0] = 0; kick[1] = 0; kick[2] = 0; kick[3] = 0; kick[4] = 0; kick[5] = 0; kick[6] = 0; kick[7] = 0; kick[8] = 0; kick[9] = 0; kick[10] = 0; kick[11] = 0; kick[12] = 0; kick[13] = 0; kick[14] = 0; kick[15] = 0; snare[0] = 0; snare[1] = 0; snare[2] = 0; snare[3] = 0; snare[4] = 0; snare[5] = 0; snare[6] = 0; snare[7] = 0; snare[8] = 0; snare[9] = 0; snare[10] = 0; snare[11] = 0; snare[12] = 0; snare[13] = 0; snare[14] = 0; snare[15] = 0; hihat[0] = 0; hihat[1] = 0; hihat[2] = 0; hihat[3] = 0; hihat[4] = 0; hihat[5] = 0; hihat[6] = 0; hihat[7] = 0; hihat[8] = 0; hihat[9] = 0; hihat[10] = 0; hihat[11] = 0; hihat[12] = 0; hihat[13] = 0; hihat[14] = 0; hihat[15] = 0; bass[0] = 0; bass[1] = 0; bass[2] = 0; bass[3] = 0; bass[4] = 0; bass[5] = 0; bass[6] = 0; bass[7] = 0; bass[8] = 0; bass[9] = 0; bass[10] = 0; bass[11] = 0; bass[12] = 0; bass[13] = 0; bass[14] = 0; bass[15] = 0,
        variant: "destructive"
      }
    ]

    text "🔴 Streaming via ws://localhost:9100 — open another tab to collab!" { variant: "muted" }
  ]