Add support for pitch bending with MIDI

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>sh.ball</groupId>
     <artifactId>osci-render</artifactId>
-    <version>1.11.4</version>
+    <version>1.11.5</version>
 
     <name>osci-render</name>
 

src/main/java/sh/ball/audio/AudioPlayer.java

@@ -14,10 +14,14 @@ public interface AudioPlayer<S> extends Runnable {
 
   boolean isPlaying();
 
-  void setFrequency(double frequency);
+  void setBaseFrequency(double frequency);
+
+  void setPitchBendFactor(double pitchBend);
 
   double getFrequency();
 
+  double getBaseFrequency();
+
   void addFrame(S frame);
 
   void addEffect(Object identifier, Effect effect);

src/main/java/sh/ball/audio/ShapeAudioPlayer.java

@@ -44,6 +44,7 @@ public class ShapeAudioPlayer implements AudioPlayer<List<Shape>> {
   private double lengthDrawn = 0;
   private int count = 0;
   private double frequency = MIDDLE_C;
+  private double pitchBend = 1.0;
   private double trace = 0.5;
 
   private AudioDevice device;
@@ -133,16 +134,27 @@ public class ShapeAudioPlayer implements AudioPlayer<List<Shape>> {
   }
 
   @Override
-  public void setFrequency(double frequency) {
+  public void setBaseFrequency(double frequency) {
     this.frequency = frequency;
     updateLengthIncrement();
   }
 
   @Override
-  public double getFrequency() {
+  public void setPitchBendFactor(double pitchBend) {
+    this.pitchBend = pitchBend;
+    updateLengthIncrement();
+  }
+
+  @Override
+  public double getBaseFrequency() {
     return frequency;
   }
 
+  @Override
+  public double getFrequency() {
+    return frequency * pitchBend;
+  }
+
   private Shape getCurrentShape() {
     if (frame.size() == 0) {
       return new Vector2();
@@ -154,7 +166,8 @@ public class ShapeAudioPlayer implements AudioPlayer<List<Shape>> {
   private void updateLengthIncrement() {
     double totalLength = Shape.totalLength(frame);
     int sampleRate = device.sampleRate();
-    lengthIncrement = Math.max(totalLength / (sampleRate / frequency), MIN_LENGTH_INCREMENT);
+    double actualFrequency = frequency * pitchBend;
+    lengthIncrement = Math.max(totalLength / (sampleRate / actualFrequency), MIN_LENGTH_INCREMENT);
   }
 
   @Override

src/main/java/sh/ball/gui/Controller.java

@@ -54,6 +54,9 @@ public class Controller implements Initializable, FrequencyListener, MidiListene
 
   private static final InputStream DEFAULT_OBJ = Controller.class.getResourceAsStream("/models/cube.obj");
   private static final double MAX_FREQUENCY = 12000;
+  private static final int PITCH_BEND_DATA_LENGTH = 7;
+  private static final int PITCH_BEND_MAX = 16383;
+  private static final int PITCH_BEND_SEMITONES = 2;
 
   private final FileChooser fileChooser = new FileChooser();
   private final DirectoryChooser folderChooser = new DirectoryChooser();
@@ -213,7 +216,7 @@ public class Controller implements Initializable, FrequencyListener, MidiListene
 
   private Map<Slider, Consumer<Double>> initializeSliderMap() {
     return Map.of(
-      frequencySlider, f -> audioPlayer.setFrequency(Math.pow(MAX_FREQUENCY, f)),
+      frequencySlider, f -> audioPlayer.setBaseFrequency(Math.pow(MAX_FREQUENCY, f)),
       rotateSpeedSlider, rotateEffect::setSpeed,
       translationSpeedSlider, translateEffect::setSpeed,
       scaleSlider, scaleEffect::setScale,
@@ -631,7 +634,7 @@ public class Controller implements Initializable, FrequencyListener, MidiListene
 
   private void playNote(double frequency, double volume) {
     frequencySlider.setValue(Math.log(frequency) / Math.log(MAX_FREQUENCY));
-    audioPlayer.setFrequency(frequency);
+    audioPlayer.setBaseFrequency(frequency);
     scaleSlider.setValue(volume);
   }
 
@@ -688,6 +691,19 @@ public class Controller implements Initializable, FrequencyListener, MidiListene
         }
         playNote(frequency, volume);
       }
+    } else if (command == ShortMessage.PITCH_BEND) {
+      // using these instructions https://sites.uci.edu/camp2014/2014/04/30/managing-midi-pitchbend-messages/
+
+      int pitchBend = (message.getData2() << PITCH_BEND_DATA_LENGTH) | message.getData1();
+      // get pitch bend in range -1 to 1
+      double pitchBendFactor = (double) pitchBend / PITCH_BEND_MAX;
+      pitchBendFactor = 2 * pitchBendFactor - 1;
+      pitchBendFactor *= PITCH_BEND_SEMITONES;
+      // 12 tone equal temperament
+      pitchBendFactor /= 12;
+      pitchBendFactor = Math.pow(2, pitchBendFactor);
+
+      audioPlayer.setPitchBendFactor(pitchBendFactor);
     }
   }