Make sure prematurely interrupted envelopes get garbage collected

Fixes #29

Author: kevinstadler

src/processing/sound/Engine.java

@@ -396,14 +396,18 @@ protected void disconnectFromOutput(int channel, UnitSource source, int part) {
 	}
 
 	protected void play(UnitSource source) {
-		// TODO check if unit is already connected
-		// source.getOutput().isConnected()
-		for (int i = 0; i < source.getOutput().getNumParts(); i++) {
-			this.connectToOutput((this.outputChannel + i) % this.synth.getAudioDeviceManager().getMaxOutputChannels(this.outputDevice), source, i);
-			// source.getOutput().connect(i, this.volume[(this.outputChannel + i) % this.synth.getAudioDeviceManager().getMaxOutputChannels(this.outputDevice)].inputA, 0);
-			if (this.multiChannelMode) {
-				// only add the first (left) channel
-				break;
+		// check if unit is already connected
+		UnitGenerator generator = source.getUnitGenerator();
+		if (!this.addedUnits.contains(generator)) {
+			this.synth.add(generator);
+			this.addedUnits.add(generator);
+			for (int i = 0; i < source.getOutput().getNumParts(); i++) {
+				this.connectToOutput((this.outputChannel + i) % this.synth.getAudioDeviceManager().getMaxOutputChannels(this.outputDevice), source, i);
+				// source.getOutput().connect(i, this.volume[(this.outputChannel + i) % this.synth.getAudioDeviceManager().getMaxOutputChannels(this.outputDevice)].inputA, 0);
+				if (this.multiChannelMode) {
+					// only add the first (left) channel
+					break;
+				}
 			}
 		}
 	}
@@ -415,6 +419,7 @@ protected void stop(UnitSource source) {
 			for (int i : IntStream.range(0, source.getOutput().getNumParts()).toArray()) {
 				source.getOutput().disconnectAll(i);
 			}
+			// removal happens inside
 			this.remove(source.getUnitGenerator());
 		}
 	}

src/processing/sound/Env.java

@@ -1,8 +1,10 @@
 package processing.sound;
 
 import com.jsyn.data.SegmentedEnvelope;
+import com.jsyn.ports.QueueDataCommand;
+import com.jsyn.ports.QueueDataEvent;
+import com.jsyn.ports.UnitDataQueueCallback;
 import com.jsyn.unitgen.VariableRateMonoReader;
-import com.softsynth.shared.time.TimeStamp;
 
 import processing.core.PApplet;
 
@@ -35,23 +37,43 @@ public void play(SoundObject input, float attackTime, float sustainTime, float s
 				sustainTime, sustainLevel * input.amp, // sustain
 				releaseTime, 0.0 });
 
-		// TODO re-use player from fixed or dynamic pool
+		// fire-and-forget envelope player
 		VariableRateMonoReader player = new VariableRateMonoReader();
-
-		// this would make sense to me but breaks the envelope for some reason
-//		input.amplitude.disconnectAll();
-		player.output.connect(input.amplitude);
 		Engine.getEngine().add(player);
+		// we need to start the player explicitly, otherwise if it gets disconnected 
+		// by another envelope kicking in before it has completed, it would stop 
+		// prematurely and the callback (which removes it from the synth for garbage 
+		// collection) would never get called!
+		player.start();
 
-		player.dataQueue.queue(env);
+		input.amplitude.disconnectAll();
+		player.output.connect(input.amplitude);
 		if (!input.isPlaying()) {
 			input.play();
 		}
 
-		// disconnect player from amplitude port after finished and set amplitude to 0
-		TimeStamp envFinished = Engine.getEngine().synth.createTimeStamp().makeRelative(attackTime + sustainTime + releaseTime);
-		player.output.disconnect(0, input.amplitude, 0, envFinished);
-		// TODO better: trigger unit stop() so that isPlaying() is set to false as well?
-		input.amplitude.set(0, envFinished);
+		QueueDataCommand cmd = player.dataQueue.createQueueDataCommand(env, 0, env.getNumFrames());
+		// need to set auto stop for the remove() inside the callback to work
+		cmd.setAutoStop(true);
+		cmd.setCallback(new UnitDataQueueCallback() {
+			public void finished(QueueDataEvent event) {
+				// check if this output has maybe already been disconnected (by a new 
+				// envelope that has taken over)
+				if (player.output.isConnected()) {
+					player.output.disconnectAll();
+					// TODO what to do with the input soundobject after the envelope is 
+					// finished? just silence it, but then it isn't automatically garbage 
+					// collected? should we trigger the object's stop() as well?
+					input.amplitude.set(0);
+				}
+				Engine.getEngine().remove(player);
+			}
+			public void looped(QueueDataEvent event) {
+			}
+			public void started(QueueDataEvent event) {
+			}
+		});
+
+		player.getSynthesizer().queueCommand(cmd);
 	}
 }

src/processing/sound/SoundObject.java

@@ -98,7 +98,6 @@ public void pan(float pos) {
 	public void play() {
 		// TODO print info message if it's already playing?
 		if (!this.isPlaying) {
-			Engine.getEngine().add(this.circuit);
 			Engine.getEngine().play(this.circuit);
 			this.setAmplitude();
 			this.isPlaying = true;