automation-events/src/functions/truncate-value-curve.ts

A module which provides an implementation of an automation event list.

import { interpolateValue } from './interpolate-value';

export const truncateValueCurve = <Values extends number[] | Float32Array>(
    values: Values,
    originalDuration: number,
    targetDuration: number
): Values => {
    const length = values.length;
    const truncatedLength = Math.max(1, Math.floor((targetDuration / originalDuration) * length)) + 1;
    const truncatedValues = values instanceof Float32Array ? new Float32Array(truncatedLength) : values.slice(0, truncatedLength);

    for (let i = 0; i < truncatedLength; i += 1) {
        const time = (i / (truncatedLength - 1)) * targetDuration;
        const theoreticIndex = (time / originalDuration) * (length - 1);

        truncatedValues[i] = interpolateValue(values, theoreticIndex);
    }

    return <Values>truncatedValues;
};