| 1 | // Headless Strudel: the strudel.cc REPL with the browser taken out from under it. |
| 2 | // |
| 3 | // Strudel is layered more cleanly than it looks. The pattern algebra, the |
| 4 | // mini-notation parser, the transpiler and the scheduler are all pure JS with no |
| 5 | // DOM dependency whatsoever — the only thing that ever needed a browser is the |
| 6 | // output stage, superdough, which speaks Web Audio. `repl()` takes both the |
| 7 | // clock (`getTime`) and the output (`defaultOutput`) as constructor arguments, |
| 8 | // so pointing them at a native AudioContext is enough to run the whole thing in |
| 9 | // Node. See browser-shim.ts and loader-hooks.ts for the glue that gets |
| 10 | // superdough itself to import. |
| 11 | // |
| 12 | // Import order matters and is load-bearing: the shim must be fully evaluated |
| 13 | // before anything reaches for `AudioContext` or `window` at module scope. Static |
| 14 | // imports are hoisted in source order, so keeping the shim first is sufficient — |
| 15 | // do not reorder these. |
| 16 | import './browser-shim.ts'; |
| 17 | |
| 18 | import { repl, evalScope, controls, silence } from '@strudel/core'; |
| 19 | import type { Hap, Repl, ReplState } from '@strudel/core'; |
| 20 | import { transpiler } from '@strudel/transpiler'; |
| 21 | import * as core from '@strudel/core'; |
| 22 | |
| 23 | import { |
| 24 | setAudioContext, |
| 25 | getAudioContext, |
| 26 | loadWorklets, |
| 27 | samples, |
| 28 | aliasBank, |
| 29 | registerSynthSounds, |
| 30 | registerZZFXSounds, |
| 31 | superdough, |
| 32 | } from 'superdough'; |
| 33 | |
| 34 | const DOUGH = 'https://raw.githubusercontent.com/felixroos/dough-samples/main'; |
| 35 | const UZU = 'https://raw.githubusercontent.com/tidalcycles/uzu-drumkit/main'; |
| 36 | const TODEPOND = 'https://raw.githubusercontent.com/todepond/samples/main'; |
| 37 | |
| 38 | // superdough's own webaudioOutput lives in @strudel/webaudio, which pulls in a |
| 39 | // pile of browser-only siblings we don't want. The output contract is small |
| 40 | // enough to just implement: turn a hap into a superdough call at a wall-clock |
| 41 | // deadline. This mirrors @strudel/webaudio's webaudioOutput. |
| 42 | function nodeAudioOutput(hap: Hap, deadline: number, duration: number, cps: number): void { |
| 43 | const { s, note, n } = hap.value; |
| 44 | if (s === undefined && note === undefined && n === undefined) { |
| 45 | // Nothing to sound — a control-only hap (e.g. a bare `.gain()` with no source). |
| 46 | return; |
| 47 | } |
| 48 | const ctx = getAudioContext(); |
| 49 | superdough({ ...hap.value, cps }, ctx.currentTime + deadline, duration, cps); |
| 50 | } |
| 51 | |
| 52 | export interface EngineHandlers { |
| 53 | onEval?: (state: ReplState) => void; |
| 54 | onError?: (err: Error) => void; |
| 55 | onToggle?: (started: boolean) => void; |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * Boot the audio stack: native AudioContext, superdough's worklets, and the |
| 60 | * default strudel.cc sound library. |
| 61 | * |
| 62 | * `onProgress` is called with short status strings so a UI can show what's |
| 63 | * happening — the sample banks are a few MB of JSON and take a moment. |
| 64 | */ |
| 65 | export async function initAudio( |
| 66 | { onProgress = (): void => {} }: { onProgress?: (msg: string) => void } = {}, |
| 67 | ): Promise<AudioContext> { |
| 68 | const ctx = new globalThis.AudioContext(); |
| 69 | setAudioContext(ctx); |
| 70 | |
| 71 | onProgress('loading worklets'); |
| 72 | await loadWorklets(); |
| 73 | |
| 74 | onProgress('loading sounds'); |
| 75 | await Promise.all([ |
| 76 | registerSynthSounds(), |
| 77 | registerZZFXSounds(), |
| 78 | samples(`${DOUGH}/tidal-drum-machines.json`), |
| 79 | samples(`${DOUGH}/piano.json`), |
| 80 | samples(`${DOUGH}/Dirt-Samples.json`), |
| 81 | samples(`${DOUGH}/vcsl.json`), |
| 82 | samples(`${DOUGH}/mridangam.json`), |
| 83 | samples(`${UZU}/strudel.json`), |
| 84 | ]); |
| 85 | await aliasBank(`${TODEPOND}/tidal-drum-machines-alias.json`); |
| 86 | |
| 87 | onProgress('ready'); |
| 88 | return ctx; |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Build the REPL. Returns the same surface StrudelMirror drives in the browser — |
| 93 | * evaluate/start/stop/toggle plus the live scheduler — so a terminal frontend |
| 94 | * and a web frontend are interchangeable consumers. |
| 95 | */ |
| 96 | export async function createEngine(handlers: EngineHandlers = {}): Promise<Repl> { |
| 97 | const ctx = getAudioContext(); |
| 98 | |
| 99 | // Everything the user's code can call by bare name — `s`, `note`, `stack`, |
| 100 | // mini-notation, the tonal helpers. Without this, evaluate() throws |
| 101 | // ReferenceError on the first `s("bd")`. |
| 102 | await evalScope(core, controls, import('@strudel/mini'), import('@strudel/tonal')); |
| 103 | |
| 104 | return repl({ |
| 105 | defaultOutput: nodeAudioOutput, |
| 106 | getTime: () => ctx.currentTime, |
| 107 | transpiler, |
| 108 | afterEval: (state) => handlers.onEval?.(state), |
| 109 | onEvalError: (err) => handlers.onError?.(err), |
| 110 | onToggle: (started) => handlers.onToggle?.(started), |
| 111 | }); |
| 112 | } |
| 113 | |
| 114 | export { silence, getAudioContext }; |
| 115 | export type { Repl, ReplState, Hap }; |