adding octaviation up or down

This commit is contained in:
2023-09-21 21:12:50 +02:00
parent 6076ea226f
commit 512523d74f

View File

@ -347,15 +347,35 @@ export const makeArrayExtensions = (api: UserAPI) => {
Array.prototype.scale = function(scale: string = "major", base_note: number = 0) {
/**
* Returns a note from an array containing a specific scale.
*
* @param scale - the scale name (string)
* @param scale - the scale name
* @param base_note - the base note to start at (MIDI note number)
*
*/
if (SCALES.hasOwnProperty(scale)) {
const selected_scale = SCALES[scale]
return this.map((value) => selected_scale[value % selected_scale.length] + base_note);
const selected_scale = SCALES[scale];
return this.map((value) => {
const octaveShift = Math.floor(value / selected_scale.length) * 12 * Math.sign(value);
return selected_scale[Math.abs(value) % selected_scale.length] + base_note + octaveShift;
});
} else {
return this.map((value) => value + base_note);
}
};
Array.prototype.scale = function(scale: string = "major", base_note: number = 0) {
/**
* @param scale - the scale name
* @param base_note - the base note to start at (MIDI note number)
*/
// This is a helper function to handle up or down octaviation.
const mod = (n: number, m: number) => ((n % m) + m) % m;
if (SCALES.hasOwnProperty(scale)) {
const selected_scale = SCALES[scale];
return this.map((value) => {
const octaveShift = Math.floor(value / selected_scale.length) * 12;
return selected_scale[mod(value, selected_scale.length)] + base_note + octaveShift;
});
} else {
return this.map((value) => value + base_note);
}