Add option to use old random and a benchmark

packages/core/bench/signal.bench.mjs

@@ -0,0 +1,46 @@
+import { describe, bench } from 'vitest';
+
+import { calculateSteps, rand, useOldRandom } from '../index.mjs';
+
+const testingResolution = 1024;
+
+const _generateRandomPattern = () => rand.iter(testingResolution).fast(testingResolution).firstCycle();
+
+describe('random', () => {
+  calculateSteps(true);
+  bench(
+    '+tactus',
+    _generateRandomPattern,
+    { time: 1000 },
+  );
+
+  calculateSteps(false);
+  bench(
+    '-tactus',
+    _generateRandomPattern,
+    { time: 1000 },
+  );
+});
+
+describe('old random', () => {
+  calculateSteps(true);
+  bench(
+    '+tactus',
+    () => {
+        useOldRandom();
+        _generateRandomPattern();
+    },
+    { time: 1000 },
+  );
+
+  calculateSteps(false);
+  bench(
+    '-tactus',
+    () => {
+        useOldRandom();
+        _generateRandomPattern();
+    },
+    { time: 1000 },
+  );
+});
+calculateSteps(true);

packages/core/signal.mjs

@@ -186,7 +186,7 @@ export const mouseY = signal(() => _mouseY);
 export const mousex = signal(() => _mouseX);
 export const mouseX = signal(() => _mouseX);
 
-// random signals
+// Random number generators
 
 // Produce "Avalanche effect" where flipping a single bit of x
 // results in all output bits flipping with probability 0.5
@@ -215,8 +215,38 @@ function randAt(t, i = 0) {
   return _murmurHashFinalizer(_decorrelate(t, i)) / 4294967296; // 2^32
 }
 
+// Deprecated: Old random signals. Configuration `useOldRandom` may be used for legacy songs
+
+// stretch 300 cycles over the range of [0,2**29 == 536870912) then apply the xorshift algorithm
+const __xorwise = (x) => {
+  const a = (x << 13) ^ x;
+  const b = (a >> 17) ^ a;
+  return (b << 5) ^ b;
+};
+const __frac = (x) => x - Math.trunc(x);
+const __timeToIntSeed = (x) => __xorwise(Math.trunc(__frac(x / 300) * 536870912));
+const __intSeedToRand = (x) => (x % 536870912) / 536870912;
+const __timeToRand = (x) => Math.abs(__intSeedToRand(__timeToIntSeed(x)));
+const __timeToRandsPrime = (seed, n) => {
+  const result = [];
+  for (let i = 0; i < n; i++) {
+    result.push(__intSeedToRand(seed));
+    seed = __xorwise(seed);
+  }
+  return result;
+};
+const __timeToRands = (t, n) => __timeToRandsPrime(__timeToIntSeed(t), n);
+
+// End old random
+
+let useOldRandomBool = false;
+export const useOldRandom = (b = true) => useOldRandomBool = b;
+
 // N samples at time t
 function timeToRands(t, n) {
+  if (useOldRandomBool) {
+    return __timeToRands(t, n);
+  }
   const out = new Array(n);
   for (let i = 0; i < n; i++) out[i] = randAt(t, i);
   return out;
@@ -224,6 +254,9 @@ function timeToRands(t, n) {
 
 // Single sample at time t
 function timeToRand(t) {
+  if (useOldRandomBool) {
+    return __timeToRand(t);
+  }
   return randAt(t, 0);
 }
 

website/src/repl/tunes.mjs

@@ -393,6 +393,8 @@ samples({
   bass: { d2: 'https://cdn.freesound.org/previews/608/608286_13074022-lq.mp3' }
 })
 
+useOldRandom(true)
+
 stack(
   // bells
   n("0").euclidLegato(3,8)
@@ -430,6 +432,7 @@ export const festivalOfFingers3 = `// "Festival of fingers 3"
 // @by Felix Roos
 
 setcps(1)
+useOldRandom(true)
 
 n("[-7*3],0,2,6,[8 7]")
   .echoWith(
@@ -454,6 +457,8 @@ export const meltingsubmarine = `// "Melting submarine"
 // @by Felix Roos
 
 samples('github:tidalcycles/dirt-samples')
+useOldRandom(true)
+
 stack(
   s("bd:5,[~ <sd:1!3 sd:1(3,4,3)>],hh27(3,4,1)") // drums
   .speed(perlin.range(.7,.9)) // random sample speed variation
@@ -602,6 +607,9 @@ export const belldub = `// "Belldub"
 
 samples({ bell: {b4:'https://cdn.freesound.org/previews/339/339809_5121236-lq.mp3'}})
 // "Hand Bells, B, Single.wav" by InspectorJ (www.jshaw.co.uk) of Freesound.org
+
+useOldRandom(true)
+
 stack(
   // bass
   note("[0 ~] [2 [0 2]] [4 4*2] [[4 ~] [2 ~] 0@2]".scale('g1 dorian').superimpose(x=>x.add(.02)))
@@ -638,6 +646,7 @@ export const dinofunk = `// "Dinofunk"
 // @by Felix Roos
 
 setcps(1)
+useOldRandom(true)
 
 samples({bass:'https://cdn.freesound.org/previews/614/614637_2434927-hq.mp3',
 dino:{b4:'https://cdn.freesound.org/previews/316/316403_5123851-hq.mp3'}})
@@ -666,6 +675,8 @@ export const sampleDemo = `// "Sample demo"
 // @license CC BY-NC-SA 4.0 https://creativecommons.org/licenses/by-nc-sa/4.0/
 // @by Felix Roos
 
+useOldRandom(true)
+
 stack(
   // percussion
   s("[woodblock:1 woodblock:2*2] snare_rim:0,gong/8,brakedrum:1(3,8),~@3 cowbell:3")
@@ -684,6 +695,8 @@ export const holyflute = `// "Holy flute"
 // @license CC BY-NC-SA 4.0 https://creativecommons.org/licenses/by-nc-sa/4.0/
 // @by Felix Roos
 
+useOldRandom(true)
+
 "c3 eb3(3,8) c4/2 g3*2"
 .superimpose(
   x=>x.slow(2).add(12),
@@ -699,6 +712,8 @@ export const flatrave = `// "Flatrave"
 // @license CC BY-NC-SA 4.0 https://creativecommons.org/licenses/by-nc-sa/4.0/
 // @by Felix Roos
 
+useOldRandom(true)
+
 stack(
   s("bd*2,~ [cp,sd]").bank('RolandTR909'),
   
@@ -727,6 +742,8 @@ export const amensister = `// "Amensister"
 
 samples('github:tidalcycles/dirt-samples')
 
+useOldRandom(true)
+
 stack(
   // amen
   n("0 1 2 3 4 5 6 7")
@@ -834,6 +851,8 @@ export const arpoon = `// "Arpoon"
 // @license CC BY-NC-SA 4.0 https://creativecommons.org/licenses/by-nc-sa/4.0/
 // @by Felix Roos
 
+useOldRandom(true)
+
 samples('github:tidalcycles/dirt-samples')
 
 n("[0,3] 2 [1,3] 2".fast(3).lastOf(4, fast(2))).clip(2)