spessasynth_core/src/soundfont/read_sf2/modulators.js

MIDI and SoundFont2/DLS library with no compromises

import { readLittleEndian, signedInt16 } from "../../utils/byte_functions/little_endian.js";
import { DecodedModulator, Modulator } from "../basic_soundfont/modulator.js";

/**
 * Reads the modulator read
 * @param modulatorChunk {RiffChunk}
 * @returns {Modulator[]}
 */
export function readModulators(modulatorChunk)
{
    let mods = [];
    while (modulatorChunk.chunkData.length > modulatorChunk.chunkData.currentIndex)
    {
        const dataArray = modulatorChunk.chunkData;
        const sourceEnum = readLittleEndian(dataArray, 2);
        const destination = readLittleEndian(dataArray, 2);
        const amount = signedInt16(dataArray[dataArray.currentIndex++], dataArray[dataArray.currentIndex++]);
        const secondarySourceEnum = readLittleEndian(dataArray, 2);
        const transformType = readLittleEndian(dataArray, 2);
        mods.push(new DecodedModulator(sourceEnum, secondarySourceEnum, destination, amount, transformType));
    }
    // remove terminal
    mods.pop();
    return mods;
}