Merge pull request #1363 from tidalcycles/berlinnoise

feat: berlin noise

packages/core/signal.mjs

@@ -486,13 +486,34 @@ export const wchooseCycles = (...pairs) => _wchooseWith(rand.segment(1), ...pair
 
 export const wrandcat = wchooseCycles;
 
-// this function expects pat to be a pattern of floats...
-export const perlinWith = (pat) => {
-  const pata = pat.fmap(Math.floor);
-  const patb = pat.fmap((t) => Math.floor(t) + 1);
+function _perlin(t) {
+  let ta = Math.floor(t);
+  let tb = ta + 1;
   const smootherStep = (x) => 6.0 * x ** 5 - 15.0 * x ** 4 + 10.0 * x ** 3;
   const interp = (x) => (a) => (b) => a + smootherStep(x) * (b - a);
-  return pat.sub(pata).fmap(interp).appBoth(pata.fmap(timeToRand)).appBoth(patb.fmap(timeToRand));
+  const v = interp(t - ta)(timeToRand(ta))(timeToRand(tb));
+  return v;
+}
+export const perlinWith = (tpat) => {
+  return tpat.fmap(_perlin);
+};
+
+function _berlin(t) {
+  const prevRidgeStartIndex = Math.floor(t);
+  const nextRidgeStartIndex = prevRidgeStartIndex + 1;
+
+  const prevRidgeBottomPoint = timeToRand(prevRidgeStartIndex);
+  const nextRidgeTopPoint = timeToRand(nextRidgeStartIndex) + prevRidgeBottomPoint;
+
+  const currentPercent = (t - prevRidgeStartIndex) / (nextRidgeStartIndex - prevRidgeStartIndex);
+  const interp = (a, b, t) => {
+    return a + (b - a) * t;
+  };
+  return interp(prevRidgeBottomPoint, nextRidgeTopPoint, currentPercent) / 2;
+}
+
+export const berlinWith = (tpat) => {
+  return tpat.fmap(_berlin);
 };
 
 /**
@@ -506,6 +527,18 @@ export const perlinWith = (pat) => {
  */
 export const perlin = perlinWith(time.fmap((v) => Number(v)));
 
+/**
+ * Generates a continuous pattern of [berlin noise](conceived by Jame Coyne and Jade Rowland as a joke but turned out to be surprisingly cool and useful,
+ * like perlin noise but with sawtooth waves), in the range 0..1.
+ *
+ * @name berlin
+ * @example
+ * // ascending arpeggios
+ * n("0!16".add(berlin.fast(4).mul(14))).scale("d:minor")
+ *
+ */
+export const berlin = berlinWith(time.fmap((v) => Number(v)));
+
 export const degradeByWith = register(
   'degradeByWith',
   (withPat, x, pat) => pat.fmap((a) => (_) => a).appLeft(withPat.filterValues((v) => v > x)),

packages/superdough/worklets.mjs

@@ -882,7 +882,6 @@ class ByteBeatProcessor extends AudioWorkletProcessor {
       const funcValue = this.func(local_t);
       let signal = (funcValue & 255) / 127.5 - 1;
       const out = signal * 0.2;
-
       for (let c = 0; c < output.length; c++) {
         //prevent speaker blowout via clipping if threshold exceeds
         output[c][i] = clamp(out, -0.4, 0.4);

test/__snapshots__/examples.test.mjs.snap

@@ -1051,6 +1051,75 @@ exports[`runs examples > example "begin" example index 0 1`] = `
 ]
 `;
 
+exports[`runs examples > example "berlin" example index 0 1`] = `
+[
+  "[ 0/1 → 1/16 | note:D3 ]",
+  "[ 1/16 → 1/8 | note:E3 ]",
+  "[ 1/8 → 3/16 | note:F3 ]",
+  "[ 3/16 → 1/4 | note:G3 ]",
+  "[ 1/4 → 5/16 | note:A3 ]",
+  "[ 5/16 → 3/8 | note:C4 ]",
+  "[ 3/8 → 7/16 | note:D4 ]",
+  "[ 7/16 → 1/2 | note:F4 ]",
+  "[ 1/2 → 9/16 | note:D4 ]",
+  "[ 9/16 → 5/8 | note:E4 ]",
+  "[ 5/8 → 11/16 | note:E4 ]",
+  "[ 11/16 → 3/4 | note:E4 ]",
+  "[ 3/4 → 13/16 | note:F3 ]",
+  "[ 13/16 → 7/8 | note:F3 ]",
+  "[ 7/8 → 15/16 | note:F3 ]",
+  "[ 15/16 → 1/1 | note:F3 ]",
+  "[ 1/1 → 17/16 | note:E3 ]",
+  "[ 17/16 → 9/8 | note:E3 ]",
+  "[ 9/8 → 19/16 | note:E3 ]",
+  "[ 19/16 → 5/4 | note:F3 ]",
+  "[ 5/4 → 21/16 | note:E3 ]",
+  "[ 21/16 → 11/8 | note:F3 ]",
+  "[ 11/8 → 23/16 | note:G3 ]",
+  "[ 23/16 → 3/2 | note:A3 ]",
+  "[ 3/2 → 25/16 | note:A3 ]",
+  "[ 25/16 → 13/8 | note:Bb3 ]",
+  "[ 13/8 → 27/16 | note:Bb3 ]",
+  "[ 27/16 → 7/4 | note:Bb3 ]",
+  "[ 7/4 → 29/16 | note:F3 ]",
+  "[ 29/16 → 15/8 | note:G3 ]",
+  "[ 15/8 → 31/16 | note:Bb3 ]",
+  "[ 31/16 → 2/1 | note:C4 ]",
+  "[ 2/1 → 33/16 | note:C4 ]",
+  "[ 33/16 → 17/8 | note:D4 ]",
+  "[ 17/8 → 35/16 | note:F4 ]",
+  "[ 35/16 → 9/4 | note:G4 ]",
+  "[ 9/4 → 37/16 | note:Bb3 ]",
+  "[ 37/16 → 19/8 | note:Bb3 ]",
+  "[ 19/8 → 39/16 | note:Bb3 ]",
+  "[ 39/16 → 5/2 | note:C4 ]",
+  "[ 5/2 → 41/16 | note:F3 ]",
+  "[ 41/16 → 21/8 | note:F3 ]",
+  "[ 21/8 → 43/16 | note:G3 ]",
+  "[ 43/16 → 11/4 | note:A3 ]",
+  "[ 11/4 → 45/16 | note:A3 ]",
+  "[ 45/16 → 23/8 | note:A3 ]",
+  "[ 23/8 → 47/16 | note:A3 ]",
+  "[ 47/16 → 3/1 | note:A3 ]",
+  "[ 3/1 → 49/16 | note:E3 ]",
+  "[ 49/16 → 25/8 | note:G3 ]",
+  "[ 25/8 → 51/16 | note:Bb3 ]",
+  "[ 51/16 → 13/4 | note:C4 ]",
+  "[ 13/4 → 53/16 | note:D4 ]",
+  "[ 53/16 → 27/8 | note:E4 ]",
+  "[ 27/8 → 55/16 | note:G4 ]",
+  "[ 55/16 → 7/2 | note:A4 ]",
+  "[ 7/2 → 57/16 | note:Bb3 ]",
+  "[ 57/16 → 29/8 | note:Bb3 ]",
+  "[ 29/8 → 59/16 | note:C4 ]",
+  "[ 59/16 → 15/4 | note:C4 ]",
+  "[ 15/4 → 61/16 | note:F3 ]",
+  "[ 61/16 → 31/8 | note:G3 ]",
+  "[ 31/8 → 63/16 | note:G3 ]",
+  "[ 63/16 → 4/1 | note:A3 ]",
+]
+`;
+
 exports[`runs examples > example "binary" example index 0 1`] = `
 [
   "[ 0/1 → 1/3 | s:hh ]",