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ftrans draft

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tyow 2026-02-01 00:39:22 -05:00
parent c2e45eb36c
commit 99295275ec
1 changed files with 65 additions and 10 deletions
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75
packages/xen/xen.mjs
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@ -28,12 +28,14 @@ function withBase(freq, scale) {
const defaultBase = 220;
const isEdo = (scale) => /^[1-9]+[0-9]*edo$/.test(scale);
// Assumes a base of 220. Returns a filtered scale based on 'indices'
// NOTE: indices functionality is unused
function getXenScale(scale, indices) {
let tune = new Tune();
if (typeof scale === 'string') {
if (/^[1-9]+[0-9]*edo$/.test(scale)) {
if (isEdo(scale)) {
scale = edo(scale);
} else if (presets[scale]) {
scale = presets[scale];
@ -72,7 +74,7 @@ function xenOffset(xenScale, offset, index = 0) {
* @param {(string | number[] )} scaleNameOrRatios
* @tags tonal
* @example
* // A major triad in 31edo:
* // A minor triad in 31edo:
* "0 8 18".xen("31edo").freq().piano()
* @example
* // You can also use xen with frequency ratios.
@ -95,23 +97,76 @@ function xenOffset(xenScale, offset, index = 0) {
// TODO (maybe): should this return freq ratios like tune does, for parity's sake?
export const xen = register('xen', function (scaleNameOrRatios, pat) {
return pat.withHaps((haps) => {
haps = haps.map(hap=>{
let hVal = hap.value
haps = haps.map((hap) => {
let hVal = hap.value;
const isObject = typeof hVal === 'object';
// If hVal is a pure value, place it on `n` so that we interpret it as an edoStep
hVal = isObject ? hVal : { n: hVal };
const { n, value, ...otherValues } = hVal;
const scale = getXenScale(scaleNameOrRatios);
let frequency = xenOffset(scale, parseNumeral(hVal.n));
// 10 is somewhat arbitrary
frequency = parseFloat(frequency.toPrecision(10));
hap.value = isObject ? {...otherValues, freq: frequency } : frequency
return hap;
// 10 is somewhat arbitrary
frequency = parseFloat(frequency.toPrecision(10));
hap.value = isObject ? { ...otherValues, freq: frequency } : frequency;
return isEdo(scaleNameOrRatios)
? hap.setContext({ ...hap.context, edoSize: scaleNameOrRatios.match(/^([1-9]+[0-9]*)edo$/)[1] })
: hap;
});
return removeUndefineds(haps)
})
return removeUndefineds(haps);
});
});
/**
* Frequency transpose. Assumes pattern either has `freq` set, or has values that can be interpreted as frequencies
* amt has optional `edoSize` param, defaults to 12.
* If haps have edoSize param set, such as from the output of `xen("edo31")`,
* `ftrans` will fallback to that instead of 12 as the default.
*
* Transposes the frequency by `amt` edoSteps
* @name ftranspose
* @synonyms ftrans, fTrans ftranspose, fTranspose
* @param {number} amt
* @param {number} edoSize (optional)
* @returns {Pattern}
*/
/* f = frequency (Hz)
n = edo (steps per octave)
x = number of steps
if 0\n = f, then x\n = f * 2^(x/n)
example: 5edo, 0\5 = 220 Hz, then 2\5 = 220*2^(2/5) = 290.29 Hz */
export const { ftrans, fTrans, ftranspose, fTranspose } = register(
['ftrans', 'fTrans', 'ftranspose', 'fTranspose'],
(amt, pat) => {
let edoSize;
let numSteps;
if (Array.isArray(amt)) {
edoSize = amt[1];
numSteps = amt[0];
} else {
numSteps = amt;
}
return pat.withHaps((haps) => {
haps = haps.map((hap) => {
let hVal = hap.value;
const isObject = typeof hVal === 'object';
hVal = isObject ? hVal : { freq: hVal };
let { freq, value, ...otherValues } = hVal;
if (edoSize == undefined && hap.context.edoSize != undefined) {
edoSize = hap.context.edoSize;
} else if (edoSize == undefined) {
edoSize = 12;
}
freq = freq * Math.pow(2, numSteps / edoSize);
hap.value = isObject ? { ...otherValues, freq } : freq;
return hap.setContext({ ...hap.context, edoSize });
});
return removeUndefineds(haps);
});
},
);
// not sure there's a point to having this and the above, seems like a proto version of the above.
export const tuning = register('tuning', function (ratios, pat) {
return pat.withHap((hap) => {