Add chorus effect implementation to ChipProcessor

Introduced chorus effect parameters (`rate`, `depth`, `mix`) and integrated real-time processing. Updated `PatchDTO` and `MainView` to support chorus controls and visualization. Enhanced MIDI handling for dynamic chorus adjustments.

.idea/misc.xml

@@ -1,4 +1,3 @@
-<?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
   <component name="FrameworkDetectionExcludesConfiguration">

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

@@ -5,8 +5,12 @@ package nl.astraeus.vst.chip
 import nl.astraeus.midi.message.SortedTimedMidiMessageList
 import nl.astraeus.midi.message.TimedMidiMessage
 import nl.astraeus.tba.SlicedByteArray
-import nl.astraeus.vst.*
+import nl.astraeus.vst.ADSR
+import nl.astraeus.vst.AudioWorkletProcessor
+import nl.astraeus.vst.currentTime
 import nl.astraeus.vst.midi.MidiMessageHandler
+import nl.astraeus.vst.registerProcessor
+import nl.astraeus.vst.sampleRate
 import org.khronos.webgl.Float32Array
 import org.khronos.webgl.get
 import org.khronos.webgl.set
@@ -17,7 +21,13 @@ import kotlin.math.sin
 
 val POLYPHONICS = 20
 val PI2 = PI * 2
-
+var chorusRate = 0.25
+var chorusDepth = 0.0
+var chorusMix = 0.0
+var chorusPhase = 0.0
+val leftChorusBuffer = Float32Array(sampleRate)
+val rightChorusBuffer = Float32Array(sampleRate)
+var chorusIndex = 0
 @ExperimentalJsExport
 @JsExport
 class PlayingNote(
@@ -74,6 +84,14 @@ class VstChipProcessor : AudioWorkletProcessor() {
   var amFreq = 0.0
   var amAmp = 0.0
 
+  var chorusRate = 0.25
+  var chorusDepth = 0.0
+  var chorusMix = 0.0
+  var chorusPhase = 0.0
+  val leftChorusBuffer = Float32Array(sampleRate)
+  val rightChorusBuffer = Float32Array(sampleRate)
+  var chorusIndex = 0
+
   var attack = 0.1
   var decay = 0.2
   var sustain = 0.5
@@ -159,6 +177,20 @@ class VstChipProcessor : AudioWorkletProcessor() {
       addHandler(0xb0, 0x50) { b1, b2, b3 ->
         feedback = b3 / 127.0
       }
+      addHandler(0xb0, 0x51) { b1, b2, b3 ->
+        chorusRate = 0.01 + (b3 / 127.0) * 99.99
+      }
+      addHandler(0xb0, 0x52) { b1, b2, b3 ->
+        chorusDepth = b3 / 127.0
+      }
+      addHandler(0xb0, 0x53) { b1, b2, b3 ->
+        chorusMix = b3 / 127.0
+      }
+      addHandler(0xb0, 123) { b1, b2, b3 ->
+        for (note in notes) {
+          note?.noteRelease = currentTime
+        }
+      }
       addHandler(0xb0, 123) { b1, b2, b3 ->
         for (note in notes) {
           note?.noteRelease = currentTime
@@ -418,6 +450,52 @@ class VstChipProcessor : AudioWorkletProcessor() {
     }
     */
 
+    if (chorusMix > 0.0 && chorusDepth > 0.0) {
+      val baseDelaySamples = (sampleRate * 0.018).toInt()
+      val maxModulationSamples = sampleRate * 0.012 * chorusDepth
+
+      for (i in 0 until samples) {
+        val dryLeft = left[i]
+        val dryRight = right[i]
+
+        val leftLfo = sin(chorusPhase)
+        val rightLfo = sin(chorusPhase + PI)
+
+        val leftDelaySamples = baseDelaySamples + (leftLfo * maxModulationSamples).toInt()
+        val rightDelaySamples = baseDelaySamples + (rightLfo * maxModulationSamples).toInt()
+
+        val leftReadIndex =
+          (chorusIndex + leftChorusBuffer.length - leftDelaySamples) % leftChorusBuffer.length
+        val rightReadIndex =
+          (chorusIndex + rightChorusBuffer.length - rightDelaySamples) % rightChorusBuffer.length
+
+        val wetLeft = leftChorusBuffer[leftReadIndex]
+        val wetRight = rightChorusBuffer[rightReadIndex]
+
+        left[i] = dryLeft * (1f - chorusMix.toFloat()) + wetLeft * chorusMix.toFloat()
+        right[i] = dryRight * (1f - chorusMix.toFloat()) + wetRight * chorusMix.toFloat()
+
+        leftChorusBuffer[chorusIndex] = dryLeft
+        rightChorusBuffer[chorusIndex] = dryRight
+
+        chorusIndex++
+        chorusIndex %= leftChorusBuffer.length
+
+        chorusPhase += PI2 * chorusRate / sampleRate
+        if (chorusPhase > PI2) {
+          chorusPhase -= PI2
+        }
+      }
+    } else {
+      for (i in 0 until samples) {
+        leftChorusBuffer[chorusIndex] = left[i]
+        rightChorusBuffer[chorusIndex] = right[i]
+
+        chorusIndex++
+        chorusIndex %= leftChorusBuffer.length
+      }
+    }
+
     val delaySamples = (delay * leftDelayBuffer.length).toInt()
     for (i in 0 until samples) {
       if (delaySamples > 0) {

src/commonMain/kotlin/nl/astraeus/vst/chip/PatchDTO.kt

@@ -41,4 +41,10 @@ data class PatchDTO(
   var delayDepth: Double = 0.0,
   @JsName("feedback")
   var feedback: Double = 0.0,
+  @JsName("chorusRate")
+  var chorusRate: Double = 0.0,
+  @JsName("chorusDepth")
+  var chorusDepth: Double = 0.0,
+  @JsName("chorusMix")
+  var chorusMix: Double = 0.0,
 )

src/jsMain/kotlin/nl/astraeus/vst/chip/audio/VstChipWorklet.kt

@@ -119,6 +119,30 @@ object VstChipWorklet : AudioNode(
       )
     }
 
+
+  var chorusRate = 0.0
+    set(value) {
+      field = value
+      super.postMessage(
+        0xb0 + midiChannel, 0x51, (value * 127).toInt()
+      )
+    }
+  var chorusDepth = 0.0
+    set(value) {
+      field = value
+      super.postMessage(
+        0xb0 + midiChannel, 0x52, (value * 127).toInt()
+      )
+    }
+  var chorusMix = 0.0
+    set(value) {
+      field = value
+      super.postMessage(
+        0xb0 + midiChannel, 0x53, (value * 127).toInt()
+      )
+    }
+
+
   var recording: Float32Array? = null
 
   override fun onMessage(message: MessageEvent) {
@@ -214,6 +238,9 @@ object VstChipWorklet : AudioNode(
     delay = patch.delay
     delayDepth = patch.delayDepth
     feedback = patch.feedback
+    chorusRate = patch.chorusRate
+    chorusDepth = patch.chorusDepth
+    chorusMix = patch.chorusMix
   }
 
   fun save(): PatchDTO {
@@ -232,8 +259,12 @@ object VstChipWorklet : AudioNode(
       release = release,
       delay = delay,
       delayDepth = delayDepth,
-      feedback = feedback
+      feedback = feedback,
+      chorusRate = chorusRate,
+      chorusDepth = chorusDepth,
+      chorusMix = chorusMix,
     )
   }
 
 }
+

src/jsMain/kotlin/nl/astraeus/vst/chip/view/MainView.kt

@@ -4,11 +4,34 @@ package nl.astraeus.vst.chip.view
 
 import kotlinx.browser.document
 import kotlinx.browser.window
-import kotlinx.html.*
+import kotlinx.html.InputType
+import kotlinx.html.canvas
+import kotlinx.html.classes
+import kotlinx.html.div
+import kotlinx.html.h1
+import kotlinx.html.id
+import kotlinx.html.input
 import kotlinx.html.js.onChangeFunction
 import kotlinx.html.js.onClickFunction
 import kotlinx.html.js.onInputFunction
-import nl.astraeus.css.properties.*
+import kotlinx.html.option
+import kotlinx.html.select
+import kotlinx.html.span
+import kotlinx.html.style
+import nl.astraeus.css.properties.AlignItems
+import nl.astraeus.css.properties.BoxSizing
+import nl.astraeus.css.properties.Display
+import nl.astraeus.css.properties.FlexDirection
+import nl.astraeus.css.properties.FontWeight
+import nl.astraeus.css.properties.JustifyContent
+import nl.astraeus.css.properties.Overflow
+import nl.astraeus.css.properties.Position
+import nl.astraeus.css.properties.Transform
+import nl.astraeus.css.properties.em
+import nl.astraeus.css.properties.hsla
+import nl.astraeus.css.properties.prc
+import nl.astraeus.css.properties.px
+import nl.astraeus.css.properties.rem
 import nl.astraeus.css.style.Style
 import nl.astraeus.css.style.cls
 import nl.astraeus.komp.HtmlBuilder
@@ -29,7 +52,11 @@ import nl.astraeus.vst.ui.css.Css.noTextSelect
 import nl.astraeus.vst.ui.css.CssName
 import nl.astraeus.vst.ui.css.hover
 import org.khronos.webgl.get
-import org.w3c.dom.*
+import org.w3c.dom.CanvasRenderingContext2D
+import org.w3c.dom.Element
+import org.w3c.dom.HTMLCanvasElement
+import org.w3c.dom.HTMLInputElement
+import org.w3c.dom.HTMLSelectElement
 
 object WaveformView : Komponent() {
 
@@ -347,6 +374,47 @@ class MainView : Komponent() {
             }
           )
         }
+        div(ControlsCss.name) {
+          include(
+            KnobComponent(
+              value = VstChipWorklet.chorusRate,
+              label = "Rate",
+              minValue = 0.0,
+              maxValue = 1.0,
+              step = 2.0 / 127.0,
+              width = 100,
+              height = 120,
+            ) { value ->
+              VstChipWorklet.chorusRate = value
+            }
+          )
+          include(
+            KnobComponent(
+              value = VstChipWorklet.chorusDepth,
+              label = "Depth",
+              minValue = 0.0,
+              maxValue = 1.0,
+              step = 2.0 / 127.0,
+              width = 100,
+              height = 120,
+            ) { value ->
+              VstChipWorklet.chorusDepth = value
+            }
+          )
+          include(
+            KnobComponent(
+              value = VstChipWorklet.chorusMix,
+              label = "Mix",
+              minValue = 0.0,
+              maxValue = 1.0,
+              step = 2.0 / 127.0,
+              width = 100,
+              height = 120,
+            ) { value ->
+              VstChipWorklet.chorusMix = value
+            }
+          )
+        }
         div(ControlsCss.name) {
           include(
             ExpKnobComponent(