From bc8ff20c1fe11125a73fb988ed55e717d59154c8 Mon Sep 17 00:00:00 2001
From: rnentjes <info@nentjes.com>
Date: Fri, 23 Dec 2022 16:20:08 +0100
Subject: [PATCH] Generate sound

---
 .../kotlin/WorkletProcessor.kt                | 135 +++++++++++++-----
 1 file changed, 101 insertions(+), 34 deletions(-)

diff --git a/src/jsAudioWorkletMain/kotlin/WorkletProcessor.kt b/src/jsAudioWorkletMain/kotlin/WorkletProcessor.kt
index 7aef3ce..f07319f 100644
--- a/src/jsAudioWorkletMain/kotlin/WorkletProcessor.kt
+++ b/src/jsAudioWorkletMain/kotlin/WorkletProcessor.kt
@@ -1,6 +1,7 @@
 @file:OptIn(ExperimentalJsExport::class)
 
 import org.khronos.webgl.Float64Array
+import org.khronos.webgl.get
 import org.khronos.webgl.set
 import org.w3c.dom.MessageEvent
 import org.w3c.dom.MessagePort
@@ -11,10 +12,20 @@ import kotlin.math.sin
 @JsExport
 object WorkletProcessor {
   var port: MessagePort? = null
-  var offset: Double = 0.0
+
+  var offsets = Array(5) { 0.0 }
   var counter: Int = 0
-  var note = Note.C0
-  var directionUp = true
+  var baseNote = Note.C2
+  val CARRAY = arrayOf(
+    Note.C1,
+    Note.C2,
+    Note.C3,
+    Note.C4,
+    Note.C5,
+    Note.C6,
+    Note.C7,
+    Note.C8,
+  )
 
   @JsName("setPort")
   fun setPort(port: MessagePort) {
@@ -30,9 +41,11 @@ object WorkletProcessor {
       "start" -> {
         println("Start worklet!")
       }
+
       "stop" -> {
 
       }
+
       else ->
         console.error("Don't kow how to handle message", message)
     }
@@ -40,42 +53,96 @@ object WorkletProcessor {
 
   @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
+    var first = true
+    for (index in offsets.indices) {
+      var offset = offsets[index]
+      var tmpCounter = counter
+      var offsetNote = baseNote.transpose(index * 12)
+      var delta = offsetNote.sampleDelta
+
+      for (sample in 0 until samples) {
+        var value = sin(offset * 2 * PI)
+        offset += delta
+
+        val noteProgress = tmpCounter % 5000
+        if (noteProgress == 0) {
+          offsetNote = offsetNote.transpose(1)
+          if (offsetNote in CARRAY) {
+            offsetNote = offsetNote.transpose(-12)
+          }
+          delta = offsetNote.sampleDelta
         }
-        if (note == Note.C0) {
-          directionUp = true
+        value *= (1.0 - noteProgress / 5000.0)
+
+        if (first) {
+          left[sample] = value
+          right[sample] = value
+        } else {
+          left[sample] = left[sample] + value
+          right[sample] = right[sample] + value
         }
+        tmpCounter++
       }
-      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++
+      offsets[index] = offset
+      first = false
     }
+
+    var tmpCounter = counter
+    for (sample in 0 until samples) {
+      if (tmpCounter % 5000 == 0) {
+        baseNote = baseNote.transpose(1)
+        if (baseNote in CARRAY) {
+          baseNote = baseNote.transpose(-12)
+        }
+      }
+      tmpCounter++
+    }
+    counter += samples
+
+    val nrOffsets = offsets.size
+    for (sample in 0 until samples) {
+      left[sample] = left[sample] / nrOffsets
+      right[sample] = right[sample] / nrOffsets
+    }
+
+    /*    for (sample in 0 until samples) {
+          val noteProgress = counter % 5000
+          if (noteProgress == 0) {
+            baseNote = baseNote.transpose(1)
+            if (baseNote == Note.C3s) {
+              baseNote = Note.C2
+            }
+          }
+          var value = 0.0
+          var volumeAdjust = (Note.C3.ordinal - baseNote.ordinal) / 12.0
+          for (index in 0 until offsets.size) {
+            offsets[index] = (offsets[index] + (baseNote.transpose(index * 12).sampleDelta)) % 1.0
+
+            var partValue = sin(offsets[index] * 2 * PI)
+            if (index == 0) {
+              partValue *= volumeAdjust
+            } else if (index == offsets.size - 1) {
+              partValue *= (1.0 - volumeAdjust)
+            }
+
+            value += partValue
+
+          }
+
+          value /= offsets.size
+          // simple amplitude
+          value *= if (noteProgress < 0.1) {
+            (noteProgress / 500.0)
+          } else {
+            (1.0 - (noteProgress - 0.1) / 4500.0)
+          }
+
+          left[sample] = value
+          right[sample] = value
+
+          counter++
+        }*/
   }
 
 }