add coarse, crush and shape

packages/webaudio/worklets.mjs

@@ -0,0 +1,94 @@
+// all the credit goes to webdirt: https://github.com/dktr0/WebDirt/blob/5ce3d698362c54d6e1b68acc47eb2955ac62c793/dist/AudioWorklets.js
+
+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);