mirror/strudel
1
0
Fork 0
mirror of https://codeberg.org/uzu/strudel synced 2026-10-23 14:41:46 -04:00
Code Issues Packages Projects Releases Wiki Activity

Negative steps change euclid into euclidLegato and vice versa

Browse Source 
Also fix that euclidLegato did not support negative pulses for inversion
This commit is contained in:
Tijmen Zwaan
2026-08-13 04:00:41 +02:00
parent 8f81463b9c
commit d7384dfc3d
3 changed files with 135 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files
packages/core/euclid.mjs
+29 -6
View File
@@ -59,6 +59,11 @@ export const bjorklund = function (ons, steps) {
* really useful for computer/algorithmic music because they can
* describe a large number of rhythms with a couple of numbers.
*
* A negative number of pulses inverts the pattern
* so pulses happen in the gaps of the normal euclidean rhythm.
*
* A negative number of steps changes it into `euclidLegato`.
*
* @memberof Pattern
* @name euclid
* @tags temporal
@@ -138,6 +143,9 @@ const _euclidRot = function (pulses, steps, rotation) {
};
export const euclid = register('euclid', function (pulses, steps, pat) {
if (steps < 0) {
return _euclidLegato(pulses, -steps, 0, pat);
}
return pat.struct(_euclidRot(pulses, steps, 0));
});
@@ -150,12 +158,17 @@ export const bjork = register('bjork', function (euc, pat) {
});
export const { euclidrot, euclidRot } = register(['euclidrot', 'euclidRot'], function (pulses, steps, rotation, pat) {
if (steps < 0) {
return _euclidLegato(pulses, -steps, rotation, pat);
}
return pat.struct(_euclidRot(pulses, steps, rotation));
});
/**
* Similar to `euclid`, but each pulse is held until the next pulse,
* so there will be no gaps.
*
* A negative number of steps changes it into `euclid`.
* @name euclidLegato
* @memberof Pattern
* @tags temporal
@@ -168,26 +181,33 @@ export const { euclidrot, euclidRot } = register(['euclidrot', 'euclidRot'], fun
*/
const _euclidLegato = function (pulses, steps, rotation, pat) {
if (pulses < 1) {
return silence;
}
const bin_pat = _euclidRot(pulses, steps, 0);
var bin_pat = _euclidRot(pulses, steps, 0);
// Because the `gapless` algorithm logic assumes the first entry in bin_pat is a 1,
// we rotate the pattern so the first onset is at the start.
const firstOnset = bin_pat.indexOf(1);
bin_pat = rotate(bin_pat, firstOnset);
steps = Math.abs(steps);
const gapless = bin_pat
.join('')
.split('1')
.slice(1)
.map((s) => [s.length + 1, true]);
return pat.struct(timeCat(...gapless)).late(Fraction(rotation).div(steps));
return pat.struct(timeCat(...gapless)).late(Fraction(rotation + firstOnset).div(steps));
};
export const euclidLegato = register(['euclidLegato'], function (pulses, steps, pat) {
if (steps < 0) {
return pat.struct(_euclidRot(pulses, -steps, 0));
}
return _euclidLegato(pulses, steps, 0, pat);
});
/**
* Similar to `euclid`, but each pulse is held until the next pulse,
* so there will be no gaps, and has an additional parameter for 'rotating'
* the resulting sequence
* the resulting sequence.
*
* A negative number of steps changes it into `euclidRot`.
* @name euclidLegatoRot
* @memberof Pattern
* @tags temporal
@@ -198,6 +218,9 @@ export const euclidLegato = register(['euclidLegato'], function (pulses, steps,
* note("c3").euclidLegatoRot(3,5,2)
*/
export const euclidLegatoRot = register(['euclidLegatoRot'], function (pulses, steps, rotation, pat) {
if (steps < 0) {
return pat.struct(_euclidRot(pulses, -steps, rotation));
}
return _euclidLegato(pulses, steps, rotation, pat);
});
packages/core/test/euclid.test.js
+56
View File
@@ -29,6 +29,34 @@ describe('euclid', () => {
.map((a) => a.showWhole(true)),
).toStrictEqual(['0/1 → 1/8: a', '1/4 → 3/8: a', '3/8 → 1/2: a', '5/8 → 3/4: a', '3/4 → 7/8: a']);
});
it('Can create euclidLegato using negative steps', () => {
expect(
fastcat('a')
.euclid(3, -8)
.firstCycle()
.sort((a, b) => a.part.begin.sub(b.part.begin))
.map((a) => a.showWhole(true)),
).toStrictEqual(
fastcat('a')
.euclidLegato(3, 8)
.firstCycle()
.sort((a, b) => a.part.begin.sub(b.part.begin))
.map((a) => a.showWhole(true)),
);
expect(
fastcat('a')
.euclid(5, -8)
.firstCycle()
.sort((a, b) => a.part.begin.sub(b.part.begin))
.map((a) => a.showWhole(true)),
).toStrictEqual(
fastcat('a')
.euclidLegato(5, 8)
.firstCycle()
.sort((a, b) => a.part.begin.sub(b.part.begin))
.map((a) => a.showWhole(true)),
);
});
});
describe('euclidRot', () => {
@@ -67,6 +95,34 @@ describe('euclidLegato', () => {
.map((a) => a.showWhole(true)),
).toStrictEqual(['0/1 → 1/4: a', '1/4 → 3/8: a', '3/8 → 5/8: a', '5/8 → 3/4: a', '3/4 → 1/1: a']);
});
it('Can create euclid using negative steps', () => {
expect(
fastcat('a')
.euclidLegato(3, -8)
.firstCycle()
.sort((a, b) => a.part.begin.sub(b.part.begin))
.map((a) => a.showWhole(true)),
).toStrictEqual(
fastcat('a')
.euclid(3, 8)
.firstCycle()
.sort((a, b) => a.part.begin.sub(b.part.begin))
.map((a) => a.showWhole(true)),
);
expect(
fastcat('a')
.euclidLegato(5, -8)
.firstCycle()
.sort((a, b) => a.part.begin.sub(b.part.begin))
.map((a) => a.showWhole(true)),
).toStrictEqual(
fastcat('a')
.euclid(5, 8)
.firstCycle()
.sort((a, b) => a.part.begin.sub(b.part.begin))
.map((a) => a.showWhole(true)),
);
});
});
describe('euclidLegatoRot', () => {
packages/mini/test/mini.test.mjs
+50
View File
@@ -84,6 +84,22 @@ describe('mini', () => {
it('supports patterning euclidean rhythms', () => {
expect(minS('[a(<3 5>, <8 16>)]*2')).toEqual(minS('a(3,8) a(5,16)'));
});
it('supports inverted euclidean rhythms', () => {
expect(minS('a(-3, 8)')).toEqual(['a: 1/8 - 1/4', 'a: 1/4 - 3/8', 'a: 1/2 - 5/8', 'a: 5/8 - 3/4', 'a: 7/8 - 1']);
});
it('supports euclidean legato rhythms', () => {
expect(minS('a(3, -8)')).toEqual(['a: 0 - 3/8', 'a: 3/8 - 3/4', 'a: 3/4 - 1']);
});
it('supports inverted euclidean legato rhythms', () => {
expect(minS('a(-3, -8)')).toEqual([
'a: -1/8 - 1/8',
'a: 1/8 - 1/4',
'a: 1/4 - 1/2',
'a: 1/2 - 5/8',
'a: 5/8 - 7/8',
'a: 7/8 - 9/8',
]);
});
it("reproduces Toussaint's example euclidean algorithms", () => {
const checkEuclid = function (spec, target) {
expect(minS(`x(${spec[0]},${spec[1]})`)).toEqual(minS(target));
@@ -118,6 +134,40 @@ describe('mini', () => {
checkEuclid([11, 24], 'x ~ ~ x ~ x ~ x ~ x ~ x ~ ~ x ~ x ~ x ~ x ~ x ~');
checkEuclid([13, 24], 'x ~ x x ~ x ~ x ~ x ~ x ~ x x ~ x ~ x ~ x ~ x ~');
});
it("reproduces Toussaint's example euclidean legato algorithms", () => {
const checkEuclid = function (spec, target) {
expect(minS(`x(${spec[0]},${spec[1]})`)).toEqual(minS(target));
};
checkEuclid([1, -2], 'x _');
checkEuclid([1, -3], 'x _ _');
checkEuclid([1, -4], 'x _ _ _');
checkEuclid([4, -12], 'x _ _ x _ _ x _ _ x _ _');
checkEuclid([2, -5], 'x _ x _ _');
// checkEuclid([3, 4], "x _ x x"); // Toussaint is wrong..
checkEuclid([3, -4], 'x x x _'); // correction
checkEuclid([3, -5], 'x _ x _ x');
checkEuclid([3, -7], 'x _ x _ x _ _');
checkEuclid([3, -8], 'x _ _ x _ _ x _');
checkEuclid([4, -7], 'x _ x _ x _ x');
checkEuclid([4, -9], 'x _ x _ x _ x _ _');
checkEuclid([4, -11], 'x _ _ x _ _ x _ _ x _');
// checkEuclid([5, 6], "x _ x x x x"); // Toussaint is wrong..
checkEuclid([5, -6], 'x x x x x _'); // correction
checkEuclid([5, -7], 'x _ x x _ x x');
checkEuclid([5, -8], 'x _ x x _ x x _');
checkEuclid([5, -9], 'x _ x _ x _ x _ x');
checkEuclid([5, -11], 'x _ x _ x _ x _ x _ _');
checkEuclid([5, -12], 'x _ _ x _ x _ _ x _ x _');
// checkEuclid([5, 16], "x _ _ x _ _ x _ _ x _ _ x _ _ _ _"); // Toussaint is wrong..
checkEuclid([5, -16], 'x _ _ x _ _ x _ _ x _ _ x _ _ _'); // correction
// checkEuclid([7, 8], "x _ x x x x x x"); // Toussaint is wrong..
checkEuclid([7, -8], 'x x x x x x x _'); // Correction
checkEuclid([7, -12], 'x _ x x _ x _ x x _ x _');
checkEuclid([7, -16], 'x _ _ x _ x _ x _ _ x _ x _ x _');
checkEuclid([9, -16], 'x _ x x _ x _ x _ x x _ x _ x _');
checkEuclid([11, -24], 'x _ _ x _ x _ x _ x _ x _ _ x _ x _ x _ x _ x _');
checkEuclid([13, -24], 'x _ x x _ x _ x _ x _ x _ x x _ x _ x _ x _ x _');
});
it('supports the - alias for ~', () => {
expect(minS('a - b [- c]')).toEqual(minS('a ~ b [~ c]'));
});