Fully implement JavaAudioEngine

src/main/java/sh/ball/audio/engine/JavaAudioEngine.java

@@ -2,33 +2,91 @@ package sh.ball.audio.engine;
 
 import sh.ball.shapes.Vector2;
 
+import javax.sound.sampled.AudioFormat;
+import javax.sound.sampled.AudioSystem;
+import javax.sound.sampled.SourceDataLine;
 import java.util.List;
 import java.util.concurrent.Callable;
 
 public class JavaAudioEngine implements AudioEngine {
 
+  private static final int DEFAULT_SAMPLE_RATE = 192000;
+  private static final int NUM_CHANNELS = 2;
+  private static final int LATENCY_MS = 10;
+  private static final int MAX_FRAME_LATENCY = 512;
+  private static final int BIT_DEPTH = 16;
+  private static final int FRAME_SIZE = NUM_CHANNELS * BIT_DEPTH / 8;
+  private static final boolean BIG_ENDIAN = false;
+  private static final boolean SIGNED_SAMPLE = true;
+  public static final double EPSILON = 0.1;
+
+  private volatile boolean stopped = false;
+
+  private Callable<Vector2> channelGenerator;
+  private SourceDataLine source;
+
   @Override
   public boolean isPlaying() {
-    return false;
+    return source.isRunning();
   }
 
   @Override
   public void play(Callable<Vector2> channelGenerator, AudioDevice device) throws Exception {
+    this.channelGenerator = channelGenerator;
 
+    AudioFormat format = new AudioFormat((float) device.sampleRate(), BIT_DEPTH, NUM_CHANNELS, SIGNED_SAMPLE, BIG_ENDIAN);
+
+    this.source = AudioSystem.getSourceDataLine(format);
+    source.open(format);
+
+    int frameLatency = Math.max((int) (device.sampleRate() * LATENCY_MS * 0.0005), MAX_FRAME_LATENCY);
+    int bufferSize = frameLatency * FRAME_SIZE;
+    int remainingBufferSpace = source.getBufferSize() - bufferSize;
+
+    byte[] buffer = new byte[bufferSize * 2];
+
+    source.start();
+    while (!stopped) {
+      int delta = source.available() - remainingBufferSpace;
+      if (delta > 0) {
+        int requiredSamples = (delta + bufferSize) / FRAME_SIZE;
+
+        if (requiredSamples * NUM_CHANNELS > buffer.length / 2) {
+          buffer = new byte[requiredSamples * NUM_CHANNELS * 2];
+        }
+
+        for (int i = 0; i < requiredSamples; i++) {
+          try {
+            Vector2 channels = channelGenerator.call();
+            short left = (short) (channels.getX() * Short.MAX_VALUE);
+            short right = (short) (channels.getY() * Short.MAX_VALUE);
+            buffer[i * 4] = (byte) left;
+            buffer[i * 4 + 1] = (byte) (left >> 8);
+            buffer[i * 4 + 2] = (byte) right;
+            buffer[i * 4 + 3] = (byte) (right >> 8);
+          } catch (Exception e) {
+            e.printStackTrace();
+          }
+        }
+
+        source.write(buffer, 0, requiredSamples * FRAME_SIZE);
+      }
+    }
+    source.stop();
   }
 
   @Override
   public void stop() {
-
+    stopped = true;
   }
 
   @Override
   public List<AudioDevice> devices() {
-    return null;
+    return List.of(getDefaultDevice());
   }
 
   @Override
   public AudioDevice getDefaultDevice() {
-    return null;
+    return new DefaultAudioDevice("default", "default", DEFAULT_SAMPLE_RATE, AudioSample.INT16);
   }
 }

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

@@ -11,7 +11,7 @@ import javafx.scene.input.KeyEvent;
 import javafx.scene.input.MouseEvent;
 import javafx.stage.Stage;
 import sh.ball.audio.ShapeAudioPlayer;
-import sh.ball.audio.engine.XtAudioEngine;
+import sh.ball.audio.engine.JavaAudioEngine;
 import sh.ball.engine.Vector3;
 
 import java.util.Objects;
@@ -24,7 +24,7 @@ public class Gui extends Application {
     System.setProperty("prism.lcdtext", "false");
 
     FXMLLoader loader = new FXMLLoader(getClass().getResource("/fxml/osci-render.fxml"));
-    Controller controller = new Controller(new ShapeAudioPlayer(XtAudioEngine::new));
+    Controller controller = new Controller(new ShapeAudioPlayer(JavaAudioEngine::new));
     loader.setController(controller);
     Parent root = loader.load();