Fix convertAudioBuffer.

Author: microbit-matt-hillsdon

src/board/conversions.ts

@@ -11,12 +11,11 @@ import {
   MICROBIT_HAL_ACCELEROMETER_EVT_TILT_DOWN,
   MICROBIT_HAL_ACCELEROMETER_EVT_TILT_LEFT,
   MICROBIT_HAL_ACCELEROMETER_EVT_TILT_RIGHT,
-  MICROBIT_HAL_ACCELEROMETER_EVT_TILT_UP, MICROBIT_HAL_MICROPHONE_SET_THRESHOLD_HIGH,
-  MICROBIT_HAL_MICROPHONE_SET_THRESHOLD_LOW
+  MICROBIT_HAL_ACCELEROMETER_EVT_TILT_UP,
+  MICROBIT_HAL_MICROPHONE_SET_THRESHOLD_HIGH,
+  MICROBIT_HAL_MICROPHONE_SET_THRESHOLD_LOW,
 } from "./constants";
 
-
-
 export function convertSoundThresholdNumberToString(
   value: number
 ): "low" | "high" {
@@ -95,3 +94,16 @@ export function convertAccelerometerNumberToString(value: number): string {
       throw new Error(`Invalid value ${value}`);
   }
 }
+
+export const convertAudioBuffer = (
+  heap: Uint8Array,
+  source: number,
+  target: AudioBuffer
+) => {
+  const channel = target.getChannelData(0);
+  for (let i = 0; i < channel.length; ++i) {
+    // Convert from uint8 to -1..+1 float.
+    channel[i] = (heap[source + i] / 255) * 2 - 1;
+  }
+  return target;
+};

src/board/wasm.ts

@@ -53,14 +53,4 @@ export class ModuleWrapper {
     this.module!.HEAPU8.set(packet, buf);
     return buf;
   }
-
-  convertAudioBuffer(source: number, target: AudioBuffer) {
-    const channel = target.getChannelData(0);
-    const heap = this.module.HEAPU8;
-    for (let i = 0; i < channel.length; ++i) {
-      // Convert from uint8 to -1..+1 float.
-      channel[i] = (heap[source + i] / 255) * 2 - 1;
-    }
-    return target;
-  }
 }

src/jshal.js

@@ -174,7 +174,8 @@ mergeInto(LibraryManager.library, {
 
   mp_js_hal_audio_write_data: function (buf, num_samples) {
     Module.board.audio.default.writeData(
-      Module.board.module.convertAudioBuffer(
+      Module.conversions.convertAudioBuffer(
+        Module.HEAPU8,
         buf,
         Module.board.audio.default.createBuffer(num_samples)
       )
@@ -187,7 +188,8 @@ mergeInto(LibraryManager.library, {
 
   mp_js_hal_audio_speech_write_data: function (buf, num_samples) {
     Module.board.audio.speech.writeData(
-      Module.board.module.convertAudioBuffer(
+      Module.conversions.convertAudioBuffer(
+        Module.HEAPU8,
         buf,
         Module.board.audio.speech.createBuffer(num_samples)
       )