Generate sound

src/jsAudioWorkletMain/kotlin/WorkletProcessor.kt

@@ -0,0 +1,81 @@
+@file:OptIn(ExperimentalJsExport::class)
+
+import org.khronos.webgl.Float64Array
+import org.khronos.webgl.set
+import org.w3c.dom.MessageEvent
+import org.w3c.dom.MessagePort
+import kotlin.math.PI
+import kotlin.math.sin
+
+@ExperimentalJsExport
+@JsExport
+object WorkletProcessor {
+  var port: MessagePort? = null
+  var offset: Double = 0.0
+  var counter: Int = 0
+  var note = Note.C0
+  var directionUp = true
+
+  @JsName("setPort")
+  fun setPort(port: MessagePort) {
+    WorkletProcessor.port = port
+    WorkletProcessor.port?.onmessage = WorkletProcessor::onMessage
+  }
+
+  @JsName("onMessage")
+  fun onMessage(message: MessageEvent) {
+    console.log("WorkletProcessor: Received message", message)
+
+    when (message.data) {
+      "start" -> {
+        println("Start worklet!")
+      }
+      "stop" -> {
+
+      }
+      else ->
+        console.error("Don't kow how to handle message", message)
+    }
+  }
+
+  @JsName("process")
+  fun process(samples: Int, left: Float64Array, right: Float64Array) {
+    for (sample in 0 until samples) {
+      val noteProgress = counter % 5000
+      if (noteProgress == 0) {
+        note = note.transpose(
+            if (directionUp) {
+              1
+            } else {
+              -1
+            }
+        )
+        if (note == Note.B8) {
+          directionUp = false
+        }
+        if (note == Note.C0) {
+          directionUp = true
+        }
+      }
+      offset = (offset + note.sampleDelta) % 1.0
+
+      var value = sin(offset * 2 * PI) +
+                  sin(offset * 4 * PI) * 0.6 +
+                  sin(offset * 6 * PI) * 0.35 +
+                  sin(offset * 8 * PI) * 0.2
+      // simple amplitude
+      value *= if (noteProgress < 0.1) {
+        (noteProgress / 500.0)
+      } else {
+        (1.0 - (noteProgress - 0.1) / 4500.0)
+      }
+      //val value = if (offset < 0.5) { 1.0 } else { -1.0 }
+
+      left[sample] = value
+      right[sample] = value
+
+      counter++
+    }
+  }
+
+}

src/jsAudioWorkletMain/kotlin/nl/astraeus/processor/WorkletProcessor.kt

@@ -1,46 +0,0 @@
-@file:OptIn(ExperimentalJsExport::class)
-
-package nl.astraeus.processor
-
-import org.khronos.webgl.Float64Array
-import org.w3c.dom.MessageEvent
-import org.w3c.dom.MessagePort
-
-@ExperimentalJsExport
-@JsExport
-object WorkletProcessor {
-  var port: MessagePort? = null
-
-  @JsName("setPort")
-  fun setPort(port: MessagePort) {
-    this.port = port
-    this.port?.onmessage = ::onMessage
-  }
-
-  @JsName("onMessage")
-  fun onMessage(message: MessageEvent) {
-    console.log("WorkletProcessor: Received message", message)
-
-    when (message.data) {
-      "start" -> {
-        println("Start worklet!")
-      }
-      "stop" -> {
-
-      }
-      else ->
-        console.error("Don't kow how to handle message", message)
-    }
-  }
-
-  @JsName("process")
-  fun process(samples: Int, left: Float64Array, right: Float64Array) {
-    //console.log("WorkletProcessor.process", samples)
-//    val buffer = Float64SampleBuffer(samples, left, right)
-//
-//    audioGenerator?.also { generator ->
-//      generator.fillBuffer(buffer, 0, samples, false)
-//    }
-  }
-
-}

src/jsAudioWorkletMain/resources/worklet-processor.js

@@ -15,7 +15,7 @@ class WorkletProcessor extends AudioWorkletProcessor {
 
         console.log("worklet-processor.constructor", this, audioWorklet);
 
-        audioWorklet.nl.astraeus.processor.WorkletProcessor.setPort(this.port);
+        audioWorklet.WorkletProcessor.setPort(this.port);
 
         console.log("STARTED worklet-processor.js");
     }
@@ -39,7 +39,7 @@ class WorkletProcessor extends AudioWorkletProcessor {
             } else {
                 samplesToProcess = outputs[0][0].length;
 
-                audioWorklet.nl.astraeus.processor.WorkletProcessor.process(
+                audioWorklet.WorkletProcessor.process(
                     samplesToProcess,
                     outputs[0][0],
                     outputs[0][1]