strudel-docker/packages/webaudio/worklets.mjs

// LICENSE GNU General Public License v3.0 see https://github.com/dktr0/WebDirt/blob/main/LICENSE
// all the credit goes to dktr0's webdirt: https://github.com/dktr0/WebDirt/blob/5ce3d698362c54d6e1b68acc47eb2955ac62c793/dist/AudioWorklets.js
// <3

class CoarseProcessor extends AudioWorkletProcessor {
  static get parameterDescriptors() {
    return [{ name: 'coarse', defaultValue: 1 }];
  }

  constructor() {
    super();
    this.notStarted = true;
  }

  process(inputs, outputs, parameters) {
    const input = inputs[0];
    const output = outputs[0];
    const coarse = parameters.coarse;
    const blockSize = 128;
    const hasInput = !(input[0] === undefined);
    if (hasInput) {
      this.notStarted = false;
      output[0][0] = input[0][0];
      for (let n = 1; n < blockSize; n++) {
        if (n % coarse == 0) output[0][n] = input[0][n];
        else output[0][n] = output[0][n - 1];
      }
    }
    return this.notStarted || hasInput;
  }
}

registerProcessor('coarse-processor', CoarseProcessor);

class CrushProcessor extends AudioWorkletProcessor {
  static get parameterDescriptors() {
    return [{ name: 'crush', defaultValue: 0 }];
  }

  constructor() {
    super();
    this.notStarted = true;
  }

  process(inputs, outputs, parameters) {
    const input = inputs[0];
    const output = outputs[0];
    const crush = parameters.crush;
    const blockSize = 128;
    const hasInput = !(input[0] === undefined);
    if (hasInput) {
      this.notStarted = false;
      if (crush.length === 1) {
        const x = Math.pow(2, crush[0] - 1);
        for (let n = 0; n < blockSize; n++) output[0][n] = Math.round(input[0][n] * x) / x;
      } else {
        for (let n = 0; n < blockSize; n++) {
          let x = Math.pow(2, crush[n] - 1);
          output[0][n] = Math.round(input[0][n] * x) / x;
        }
      }
    }
    return this.notStarted || hasInput;
  }
}
registerProcessor('crush-processor', CrushProcessor);

class ShapeProcessor extends AudioWorkletProcessor {
  static get parameterDescriptors() {
    return [{ name: 'shape', defaultValue: 0 }];
  }

  constructor() {
    super();
    this.notStarted = true;
  }

  process(inputs, outputs, parameters) {
    const input = inputs[0];
    const output = outputs[0];
    const shape0 = parameters.shape[0];
    const shape1 = shape0 < 1 ? shape0 : 1.0 - 4e-10;
    const shape = (2.0 * shape1) / (1.0 - shape1);
    const blockSize = 128;
    const hasInput = !(input[0] === undefined);
    if (hasInput) {
      this.notStarted = false;
      for (let n = 0; n < blockSize; n++) {
        output[0][n] = ((1 + shape) * input[0][n]) / (1 + shape * Math.abs(input[0][n]));
      }
    }
    return this.notStarted || hasInput;
  }
}

registerProcessor('shape-processor', ShapeProcessor);