added Sine node

com/danitheskunk/skunkworks/TestSound.java

@@ -1,6 +1,7 @@
 package com.danitheskunk.skunkworks;
 
 import com.danitheskunk.skunkworks.audio.AudioEngine;
+import com.danitheskunk.skunkworks.audio.nodes.Sine;
 import org.lwjgl.openal.AL;
 import org.lwjgl.openal.ALC;
 
@@ -17,6 +18,7 @@ import static org.lwjgl.openal.ALC10.*;
 public class TestSound {
 	public static void main(String args[]) throws InterruptedException {
 		var engine = new AudioEngine(44100, 256, 8);
+		engine.setNode(new Sine(engine, 440));
 		for(int i = 0; i < 120; ++i) {
 			engine.refill();
 			Thread.sleep(20);

com/danitheskunk/skunkworks/audio/AudioBuffer.java

@@ -0,0 +1,28 @@
+package com.danitheskunk.skunkworks.audio;
+
+public class AudioBuffer {
+	private double[] left;
+	private double[] right;
+
+	public AudioBuffer(int size) {
+		left = new double[size];
+		right = new double[size];
+	}
+
+	public int getSize() {
+		return left.length;
+	}
+
+	public void setSample(int pos, double left, double right) {
+		this.left[pos] = left;
+		this.right[pos] = right;
+	}
+
+	public double getLeft(int pos) {
+		return left[pos];
+	}
+
+	public double getRight(int pos) {
+		return right[pos];
+	}
+}

com/danitheskunk/skunkworks/audio/AudioEngine.java

@@ -1,11 +1,11 @@
 package com.danitheskunk.skunkworks.audio;
 
+import com.danitheskunk.skunkworks.audio.nodes.Node;
 import org.lwjgl.openal.AL;
 import org.lwjgl.openal.ALC;
 
 import java.nio.ByteBuffer;
 import java.nio.IntBuffer;
-import java.util.Random;
 
 import static org.lwjgl.openal.AL10.*;
 import static org.lwjgl.openal.ALC10.*;
@@ -17,8 +17,7 @@ public class AudioEngine {
 	private long device;
 	private long context;
 	private int source;
-	private int tick = 0;
+	private Node node;
-
 	public AudioEngine(int sampleRate, int bufferSize, int bufferCount) {
 		this.sampleRate = sampleRate;
 		this.bufferSize = bufferSize;
@@ -44,26 +43,25 @@ public class AudioEngine {
 		alSourcePlay(source);
 	}
 
+	public int getBufferSize() {
+		return bufferSize;
+	}
+
 	public void close() {
 		alcDestroyContext(context);
 		alcCloseDevice(device);
 	}
 
 	private void fillBuffer(int buffer) {
-		var buf = new double[bufferSize * 2];
-		for(int i = 0; i < bufferSize; ++i) {
-			double time = (double) tick / (double) sampleRate;
-			var s = Math.sin(2 * Math.PI * 440 * time);
-			buf[i * 2] = s;
-			buf[i * 2 + 1] = s;
-			++tick;
-		}
-
 		var shortBuffer = new short[bufferSize * 2];
-		for(int i = 0; i < bufferSize * 2; ++i) {
-			shortBuffer[i] = (short) (buf[i] * 32760);
-		}
 
+		if(node != null) {
+			var buf = node.getBuffer(0);
+			for(int i = 0; i < bufferSize; ++i) {
+				shortBuffer[i * 2 + 1] = (short) (buf.getLeft(i) * 32760);
+				shortBuffer[i * 2 + 1] = (short) (buf.getRight(i) * 32760);
+			}
+		}
 		alBufferData(buffer, AL_FORMAT_STEREO16, shortBuffer, sampleRate);
 	}
 
@@ -91,4 +89,12 @@ public class AudioEngine {
 	public int getSampleRate() {
 		return sampleRate;
 	}
+
+	public Node getNode() {
+		return node;
+	}
+
+	public void setNode(Node node) {
+		this.node = node;
+	}
 }

com/danitheskunk/skunkworks/audio/nodes/Node.java

@@ -0,0 +1,59 @@
+package com.danitheskunk.skunkworks.audio.nodes;
+
+import com.danitheskunk.skunkworks.audio.AudioBuffer;
+import com.danitheskunk.skunkworks.audio.AudioEngine;
+
+public abstract class Node {
+	private int inCount;
+	private int outCount;
+	private boolean[] isOutConnected;
+	private Node[] inConnections;
+	private int[] inConnectionSlots;
+	private AudioEngine engine;
+
+	public Node(AudioEngine engine, int inCount, int outCount) {
+		this.inCount = inCount;
+		this.outCount = outCount;
+		this.isOutConnected = new boolean[outCount];
+		this.inConnections = new Node[inCount];
+		this.inConnectionSlots = new int[inCount];
+		this.engine = engine;
+		if(outCount > 1) {
+			throw new RuntimeException("more than one out connection not yet" +
+				" " +
+				"allowed, needs handling in getBuffer to only process once");
+		}
+	}
+
+	public static void connect(Node src, int srcSlot, Node dst, int dstSlot) {
+		if(srcSlot < 0 || srcSlot >= src.outCount) {
+			throw new RuntimeException("invalid srcSlot");
+		}
+		if(dstSlot < 0 || dstSlot >= dst.inCount) {
+			throw new RuntimeException("invalid dstSlot");
+		}
+		if(src.isOutConnected[srcSlot]) {
+			throw new RuntimeException("src node slot already connected");
+		}
+		if(dst.inConnections[dstSlot] != null) {
+			throw new RuntimeException("dst node slot already connected");
+		}
+		src.isOutConnected[srcSlot] = true;
+		dst.inConnections[dstSlot] = src;
+		dst.inConnectionSlots[dstSlot] = srcSlot;
+	}
+
+	public AudioEngine getEngine() {
+		return engine;
+	}
+
+	public int getInCount() {
+		return inCount;
+	}
+
+	public int getOutCount() {
+		return outCount;
+	}
+
+	public abstract AudioBuffer getBuffer(int slot);
+}

com/danitheskunk/skunkworks/audio/nodes/Sine.java

@@ -0,0 +1,28 @@
+package com.danitheskunk.skunkworks.audio.nodes;
+
+import com.danitheskunk.skunkworks.audio.AudioBuffer;
+import com.danitheskunk.skunkworks.audio.AudioEngine;
+
+public class Sine extends Node {
+	private int tick;
+	private double freq;
+
+	public Sine(AudioEngine engine, double freq) {
+		super(engine, 0, 1);
+		tick = 0;
+		this.freq = freq;
+	}
+
+	@Override
+	public AudioBuffer getBuffer(int slot) {
+		var bufsize = getEngine().getBufferSize();
+		var buf = new AudioBuffer(bufsize);
+		for(int i = 0; i < bufsize; ++i) {
+			var time = (double) tick / (double) getEngine().getSampleRate();
+			var s = Math.sin(Math.PI * 2 * freq * time);
+			buf.setSample(i, s, s);
+			++tick;
+		}
+		return buf;
+	}
+}