Function clip

src/clip.ts:33–216

(params: ClipParams)

 * Applies the pattern to notes, then optionally adds sizzle and accent dynamics.
 */
export const clip = (params: ClipParams): NoteObject[] => {
  params = preprocessClipParams(params);

  const clipNotes: NoteObject[] = [];
  let step = 0;
  /**
   * Recursively apply pattern to notes
   *
   * Pass in a pattern array such as ['x', '-', 'x', 'x'] with a length for each element
   * The length is the HDR speed or tick length (obtained from the hdr object in this script)
   * If the element of this array is also a (pattern) array, then divide the length by
   * the length of the inner array and then call the recursive function on that inner array
   */
  const recursivelyApplyPatternToNotes = (
    patternArr: PatternElement[],
    length: number,
    parentNoteLength: number | boolean
  ) => {
    let totalLength = 0;
    patternArr.forEach((char, idx) => {
      if (typeof char === 'string') {
        let note: string[] | null = null;

        if (char === '-') {
          // note = null;
        } else if (
          char === 'R' &&
          randomInt() && // Use 1/2 probability for R to pick from param.notes
          params.randomNotes &&
          params.randomNotes.length > 0
        ) {
          note = params.randomNotes[
            randomInt(params.randomNotes.length - 1)
          ] as string[];
        } else if (params.notes) {
          note = params.notes[step] as string[];
        }

        if (char === 'x' || char === 'R') {
          step++;
        }

        // Push only note on OR off messages to the clip notes array
        if (char === 'x' || char === '-' || char === 'R') {
          clipNotes.push({
            note,
            length,
            level:
              char === 'R' && !params.randomNotes
                ? (params.accentLow as number)
                : (params.amp as number),
          });
          totalLength += length;
        }

        // In case of an underscore, simply extend the previous note's length
        if (char === '_' && clipNotes.length) {
          clipNotes[clipNotes.length - 1].length += length;