Save patch

audio-worklet/src/jsMain/kotlin/nl/astraeus/vst/chip/ChipProcessor.kt

@@ -2,8 +2,10 @@
 
 package nl.astraeus.vst.chip
 
+import nl.astraeus.vst.ADSR
 import nl.astraeus.vst.AudioWorkletProcessor
 import nl.astraeus.vst.Note
+import nl.astraeus.vst.currentTime
 import nl.astraeus.vst.registerProcessor
 import nl.astraeus.vst.sampleRate
 import org.khronos.webgl.Float32Array
@@ -19,14 +21,6 @@ import kotlin.math.sin
 val POLYPHONICS = 10
 val PI2 = PI * 2
 
-@ExperimentalJsExport
-@JsExport
-enum class NoteState {
-  ON,
-  RELEASED,
-  OFF
-}
-
 @ExperimentalJsExport
 @JsExport
 class PlayingNote(
@@ -35,17 +29,15 @@ class PlayingNote(
 ) {
   fun retrigger(velocity: Int) {
     this.velocity = velocity
-    state = NoteState.ON
     sample = 0
-    attackSamples = 2500
-    releaseSamples = 10000
+    noteStart = currentTime
+    noteRelease = null
   }
 
-  var state = NoteState.OFF
+  var noteStart = currentTime
+  var noteRelease: Double? = null
   var cycleOffset = 0.0
   var sample = 0
-  var attackSamples = 2500
-  var releaseSamples = 10000
   var actualVolume = 0f
 }
 
@@ -68,11 +60,8 @@ enum class RecordingState {
 @JsExport
 class VstChipProcessor : AudioWorkletProcessor() {
   var midiChannel = 0
-  val notes = Array(POLYPHONICS) {
-    PlayingNote(
-      0
-    )
-  }
+  val notes = Array<PlayingNote?>(POLYPHONICS) { null }
+
   var waveform = Waveform.SINE.ordinal
   var volume = 0.75f
   var dutyCycle = 0.5
@@ -80,6 +69,12 @@ class VstChipProcessor : AudioWorkletProcessor() {
   var fmAmp = 0.0
   var amFreq = 0.0
   var amAmp = 0.0
+
+  var attack = 0.1
+  var decay = 0.2
+  var sustain = 0.5
+  var release = 0.2
+
   val sampleLength = 1 / sampleRate.toDouble()
 
   val recordingBuffer = Float32Array(sampleRate / 60)
@@ -198,27 +193,49 @@ class VstChipProcessor : AudioWorkletProcessor() {
             val value = bytes[2]
 
             when (knob) {
-              0x46 -> {
+              7 -> {
                 volume = value / 127f
               }
-              0x4a -> {
-                dutyCycle = value / 127.0
-              }
-
-              0x4b -> {
-                fmFreq = value / 127.0
-              }
-
-              0x4c -> {
-                fmAmp = value / 127.0
-              }
 
               0x47 -> {
+                dutyCycle = value / 127.0
+              }
+
+              0x4a -> {
+                fmFreq = value / 127.0
+              }
+
+              0x4b -> {
+                fmAmp = value / 127.0
+              }
+
+              0x4c -> {
                 amFreq = value / 127.0
               }
+              0x4d -> {
+                amAmp = value / 127.0
+              }
+
+              0x49 -> {
+                attack = value / 127.0
+              }
+
+              0x4b -> {
+                decay = value / 127.0
+              }
+
+              0x46 -> {
+                sustain = value / 127.0
+              }
 
               0x48 -> {
-                amAmp = value / 127.0
+                release = value / 127.0
+              }
+
+              123 -> {
+                for (note in notes) {
+                  note?.noteRelease = currentTime
+                }
               }
             }
           }
@@ -238,21 +255,17 @@ class VstChipProcessor : AudioWorkletProcessor() {
 
   private fun noteOn(note: Int, velocity: Int) {
     for (i in 0 until POLYPHONICS) {
-      if (notes[i].note == note) {
-        notes[i].retrigger(velocity)
+      if (notes[i]?.note == note) {
+        notes[i]?.retrigger(velocity)
         return
       }
     }
     for (i in 0 until POLYPHONICS) {
-      if (notes[i].state == NoteState.OFF) {
+      if (notes[i] == null) {
         notes[i] = PlayingNote(
           note,
           velocity
         )
-        notes[i].state = NoteState.ON
-
-        val n = Note.fromMidi(note)
-        //console.log("Playing note: ${n.sharp} (${n.freq})")
         break
       }
     }
@@ -260,8 +273,8 @@ class VstChipProcessor : AudioWorkletProcessor() {
 
   private fun noteOff(note: Int) {
     for (i in 0 until POLYPHONICS) {
-      if (notes[i].note == note && notes[i].state == NoteState.ON) {
-        notes[i].state = NoteState.RELEASED
+      if (notes[i]?.note == note) {
+        notes[i]?.noteRelease = currentTime
         break
       }
     }
@@ -279,7 +292,7 @@ class VstChipProcessor : AudioWorkletProcessor() {
 
     var lowestNote = 200
     for (note in notes) {
-      if (note.state != NoteState.OFF) {
+      if (note != null) {
         lowestNote = min(lowestNote, note.note)
       }
     }
@@ -289,23 +302,25 @@ class VstChipProcessor : AudioWorkletProcessor() {
       recordingStart = 0
     }
 
-    for (note in notes) {
-      if (note.state != NoteState.OFF) {
+    for ((index, note) in notes.withIndex()) {
+      if (note != null) {
         val sampleDelta = Note.fromMidi(note.note).sampleDelta
 
         for (i in 0 until samples) {
           var targetVolume = note.velocity / 127f
-          if (note.state == NoteState.ON && note.sample < note.attackSamples) {
-            note.attackSamples--
-            targetVolume *= ( 1f - (note.attackSamples / 2500f))
-          } else if (note.state == NoteState.RELEASED) {
-            note.releaseSamples--
-            targetVolume *= (note.releaseSamples / 10000f)
-          }
+          targetVolume *= ADSR.calculate(
+            attack,
+            decay,
+            sustain,
+            release,
+            note.noteStart,
+            currentTime,
+            note.noteRelease
+          ).toFloat()
           note.actualVolume += (targetVolume - note.actualVolume) * 0.0001f
 
-          if (note.state == NoteState.RELEASED && note.actualVolume <= 0) {
-            note.state = NoteState.OFF
+          if (note.noteRelease != null && note.actualVolume <= 0.01) {
+            notes[index] = null
           }
 
           var cycleOffset = note.cycleOffset