Feat: drum8 kick and snare

package.json

@@ -6,13 +6,13 @@
   ],
   "devDependencies": {
     "@changesets/cli": "^2.27.7",
-    "@types/audioworklet": "^0.0.57",
+    "@types/audioworklet": "^0.0.60",
     "@types/jest": "^29.5.12",
     "esbuild": "^0.23.0",
     "jest": "^29.7.0",
     "ts-jest": "^29.1.5",
     "tsup": "^8.0.1",
-    "turbo": "^2.0.6",
+    "turbo": "^2.1.1",
     "typescript": "^5.5.3"
   },
   "jest": {

packages/drum8/README.md

@@ -0,0 +1,77 @@
+# @synthlet/drum8
+
+> Drum8 generator module for [synthlet](https://github.com/danigb/synthlet)
+
+```ts
+import { registerDrum8WorkletOnce, createDrum8 } from "@synthlet/drum8";
+
+const audioContext = new AudioContext();
+
+await registerDrum8WorkletOnce(audioContext);
+
+const kick = createDrum8(audioContext, "kick", {
+  decay: 0.2, // time in seconds
+  tone: 0.8, // number between [0-1]
+  snap: 0.2, // number between [0-1]
+});
+
+kick.connect(audioContext.destination);
+```
+
+Available instruments (wip): `kick`, `snare`
+
+## Install
+
+Full package:
+
+```bash
+npm i synthlet
+```
+
+Just this module:
+
+```bash
+npm i @synthlet/drum8
+```
+
+## Usage
+
+You need to register the audio worklet before creating any instrument. See [/README.md#register] for details.
+
+#### Create an instrument
+
+Use the `createDrum8` function:
+
+```ts
+import { createDrum8 } from "synthlet"; // or "@synthlet/drum8"
+
+const kick = createDrum8(audioContext, "kick", {
+  decay: 0.2, // time in seconds
+  tone: 0.8, // number between [0-1]
+  snap: 0.2, // number between [0-1]
+});
+
+kick.connect(audioContext.destination);
+```
+
+The second parameter is the instrument type. Available instruments (wip) are: `kick`, `snare`.
+
+The third is optional parameters:
+
+- `attack`: attack time in seconds
+- `decay`: decay time in seconds
+- `level`: volume of the synth (log scale in [0,1] interval where 0 is silence and 1 is 0dB)
+- `tone`: tone of the synth ([0,1] interval)
+- `snap`: snap sound of the synth ([0,1] interval)
+
+## References
+
+Some parts of this package are based on:
+
+- https://github.com/vincentriemer/io-808
+- https://paulbatchelor.github.io/sndkit/env
+- https://github.com/nick-thompson/drumsynth
+
+Thanks! :heart:
+
+## Licenses

packages/drum8/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "@synthlet/drum8",
+  "version": "0.1.0",
+  "description": "Drum synth module for Synthlet",
+  "keywords": [
+    "noise"
+  ],
+  "main": "dist/index.js",
+  "module": "dist/index.mjs",
+  "types": "dist/index.d.ts",
+  "files": [
+    "dist"
+  ],
+  "author": "[email protected]",
+  "license": "MIT",
+  "publishConfig": {
+    "access": "public"
+  },
+  "devDependencies": {
+    "@types/jest": "^29.5.11",
+    "jest": "^29.7.0",
+    "ts-jest": "^29.1.1"
+  },
+  "jest": {
+    "preset": "ts-jest"
+  },
+  "scripts": {
+    "worklet": "esbuild src/worklet.ts --bundle --minify | sed -e 's/^/export const PROCESSOR = \\`/' -e 's/$/\\`;/'  > src/processor.ts",
+    "lib": "tsup src/index.ts --sourcemap --dts --format esm,cjs",
+    "build": "npm run worklet && npm run lib"
+  }
+}

packages/drum8/src/drums.ts

@@ -0,0 +1,55 @@
+import {
+  createClick,
+  createEnvelope,
+  createFilter,
+  createFixedSin2,
+  createNoise,
+  decaySine,
+} from "./dsp";
+
+type Params = {
+  gate: number[];
+  attack: number[];
+  decay: number[];
+  tone: number[];
+  snap: number[];
+};
+
+export type Generator = (output: Float32Array, params: Params) => void;
+type Instrument = (sampleRate: number) => Generator;
+
+export const Kick: Instrument = (sampleRate) => {
+  const sin = decaySine(sampleRate, 90, 48);
+  const click = createClick(sampleRate, 1);
+  const env = createEnvelope(sampleRate, 0.1, 0.1);
+  const lpf = createFilter(sampleRate, 0, 1.0);
+  const softClip = Math.tanh;
+
+  return (output, params) => {
+    sin.update(params.gate[0], params.decay[0] * 0.5);
+    env.update(params.gate[0], params.attack[0], params.decay[0]);
+    lpf.update(200 + 200 * params.tone[0]);
+    for (let i = 0; i < output.length; i++) {
+      output[i] = softClip(lpf.process(sin.next() * env.next() + click.next()));
+    }
+  };
+};
+
+export const Snare: Instrument = (sampleRate) => {
+  const noise = createNoise(sampleRate);
+  const envNoise = createEnvelope(sampleRate, 0.1, 0.1);
+  const snap = createFixedSin2(sampleRate, 238, 1, 476, 1);
+  const snapEnv = createEnvelope(sampleRate, 0.01, 0.1);
+  const lpf = createFilter(sampleRate, 0, 1.0);
+
+  return (output, params) => {
+    envNoise.update(params.gate[0], params.attack[0], params.decay[0]);
+    snapEnv.update(params.gate[0], 0.01, params.snap[0]);
+    lpf.update(500 + 500 * params.tone[0]);
+    for (let i = 0; i < output.length; i++) {
+      output[i] = lpf.process(
+        noise.next() * envNoise.next() + snap.next() * snapEnv.next()
+      );
+    }
+  };
+};