Implement FlxSound.pan for stereo sounds

Author: Raltyro

source/lime/_internal/backend/html5/HTML5AudioSource.hx

@@ -251,16 +251,6 @@ class HTML5AudioSource
 
 	public function getPosition():Vector4
 	{
-		#if lime_howlerjs
-		// This should work, but it returns null (But checking the inside of the howl, the _pos is actually null... so ¯\_(ツ)_/¯)
-		/*
-			var arr = parent.buffer.__srcHowl.pos())
-			position.x = arr[0];
-			position.y = arr[1];
-			position.z = arr[2];
-		 */
-		#end
-
 		return position;
 	}
 
@@ -278,4 +268,16 @@ class HTML5AudioSource
 
 		return position;
 	}
+
+	public function getPan():Float
+	{
+		return position.x;
+	}
+
+	public function setPan(value:Float):Float
+	{
+		position.setTo(value, 0, -Math.sqrt(1 - value * value));
+		if (parent.buffer != null && parent.buffer.__srcHowl != null && parent.buffer.__srcHowl.stereo != null) parent.buffer.__srcHowl.stereo(value, id);
+		return value;
+	}
 }

source/lime/_internal/backend/native/NativeAudioSource.hx

@@ -13,6 +13,7 @@ import lime.media.vorbis.Vorbis;
 import lime.media.vorbis.VorbisFile;
 #end
 
+import lime.math.Vector2;
 import lime.math.Vector4;
 import lime.media.AudioBuffer;
 import lime.media.AudioSource;
@@ -30,6 +31,11 @@ class NativeAudioSource {
 	private static var STREAM_TIMER_FREQUENCY:Int = 100;
 	private static var STREAM_BUFFER_FREQUENCY:Int = 3;
 
+	private static var moreFormatsSupported:Null<Bool>;
+	private static var stereoAnglesExtensionSupported:Null<Bool>;
+	private static var loopPointsSupported:Null<Bool>; // TODO: implement loop Points for looped static sources
+	private static var latencyExtensionSupported:Null<Bool>;
+
 	private var parent:AudioSource;
 	private var disposed:Bool;
 	private var streamed:Bool;
@@ -54,7 +60,9 @@ class NativeAudioSource {
 	private var streamEnded:Bool;
 	private var dataLength:Float;
 
-	private var position:Vector4 = new Vector4();
+	private var position:Vector4;
+	private var angles:Vector2;
+	private var anglesArray:Array<Float>;
 	private var length:Null<Float>;
 	private var loopTime:Null<Float>;
 	private var loops:Int;
@@ -65,6 +73,10 @@ class NativeAudioSource {
 		disposed = true;
 		stop();
 
+		position = null;
+		angles = null;
+		anglesArray = null;
+
 		if (handle != null) {
 			AL.sourcei(handle, AL.BUFFER, AL.NONE);
 			AL.deleteSource(handle);
@@ -81,16 +93,26 @@ class NativeAudioSource {
 
 	public function init() {
 		if (handle != null) return;
-
 		if (disposed = (handle = AL.createSource()) == null) return;
+
+		if (position == null) position = new Vector4();
+		if (angles == null) angles = new Vector2(Math.PI / 6, -Math.PI / 6); // https://github.com/kcat/openal-soft/issues/1032
+		anglesArray = [0, 0];
+
+		if (moreFormatsSupported == null) moreFormatsSupported = AL.isExtensionPresent("AL_EXT_MCFORMATS");
+		if (stereoAnglesExtensionSupported == null) stereoAnglesExtensionSupported = AL.isExtensionPresent("AL_EXT_STEREO_ANGLES");
+		if (latencyExtensionSupported == null) latencyExtensionSupported = AL.isExtensionPresent("AL_SOFT_source_latency");
+		if (loopPointsSupported == null) loopPointsSupported = AL.isExtensionPresent("AL_SOFT_loop_points");
+
 		AL.sourcef(handle, AL.MAX_GAIN, 10);
+		AL.distanceModel(AL.NONE);
 
 		var buffer = parent.buffer;
 		var channels = buffer.channels, bitsPerSample = buffer.bitsPerSample;
 
 		// Default is just AL.FORMAT_MONO8 if it doesn't match any to avoid yo ears getting blasted
 		var isCreativeXFi = AL.getString(AL.RENDERER) == "X-Fi";
-		if (channels > 2 && (isCreativeXFi || AL.isExtensionPresent("AL_EXT_MCFORMATS"))) { // https://github.com/openalext/openalext/blob/master/AL_EXT_MCFORMATS.txt
+		if (channels > 2 && (isCreativeXFi || moreFormatsSupported)) { // https://github.com/openalext/openalext/blob/master/AL_EXT_MCFORMATS.txt
 			if (channels == 3) format = bitsPerSample == 32 ? 0x1209 : (bitsPerSample == 16 ? 0x1208 : 0x1207);
 			else if (channels == 4) format = bitsPerSample == 32 ? 0x1206 : (bitsPerSample == 16 ? 0x1205 : 0x1204);
 			else if (channels == 6) format = bitsPerSample == 32 ? 0x120C : (bitsPerSample == 16 ? 0x120B : 0x120A);
@@ -466,29 +488,65 @@ class NativeAudioSource {
 
 	public function getLatency():Float {
 		/*#if (lime >= "8.3.0")
-		if (AL.isExtensionPresent("AL_SOFT_source_latency")) {
+		if (latencyExtensionSupported) {
 			final offsets = AL.getSourcedvSOFT(handle, AL.SEC_OFFSET_LATENCY_SOFT, 2);
 			if (offsets != null) return offsets[1] * 1000;
 		}
 		#end*/
 		return 0;
 	}
 
-	public function getPosition():Vector4 return position;
+	public function getAngles():Vector2 {
+		if (angles == null) angles = new Vector2(Math.PI / 6, -Math.PI / 6);
+		return angles;
+	}
+
+	public function setAngles(left:Float, right:Float):Vector2 {
+		if (angles == null) angles = new Vector2(left, right);
+		else angles.setTo(left, right);
+
+		if (!disposed) {
+			anglesArray[0] = angles.x;
+			anglesArray[1] = angles.y;
+			AL.sourcei(handle, 0x1214/*AL.SOURCE_SPATIALIZE_SOFT*/, AL.FALSE);
+			AL.sourcefv(handle, 0x1030/*AL.STEREO_ANGLES*/, anglesArray);
+		}
+		return angles;
+	}
+
+	public function getPosition():Vector4 {
+		if (position == null) position = new Vector4();
+		return position;
+	}
 
 	public function setPosition(value:Vector4):Vector4 {
 		position.x = value.x;
 		position.y = value.y;
 		position.z = value.z;
 		position.w = value.w;
 
+		// OpenAL Soft Positions doesn't seem to do anything but panning?
 		if (!disposed) {
-			AL.distanceModel(AL.NONE);
+			AL.sourcei(handle, 0x1214/*AL.SOURCE_SPATIALIZE_SOFT*/, Math.abs(position.x) > 1e-04 ? AL.TRUE : AL.FALSE);
+			AL.sourcei(handle, AL.MAX_DISTANCE, 1);
 			AL.source3f(handle, AL.POSITION, position.x, position.y, position.z);
 		}
 		return position;
 	}
 
+	public function getPan():Float return getPosition().x;
+
+	public function setPan(value:Float):Float {
+		getPosition().setTo(value, 0, -Math.sqrt(1 - value * value));
+		if (!disposed) {
+			if (parent.buffer.channels > 1 && stereoAnglesExtensionSupported)
+				setAngles(Math.PI * (Math.min(-value * 2 + 1, 1)) / 6, -Math.PI * Math.min(value * 2 + 1, 1) / 6);
+			else
+				setPosition(position);
+		}
+		return value;
+	}
+
 	inline private function getFloat(x:Int64):Float return x.high * 4294967296. + (x.low >> 0);
 	inline private function getSamples(ms:Float):Int64 return Int64.fromFloat(Math.max(0, Math.min(ms / 1000 * parent.buffer.sampleRate, samples)));
 }

source/lime/media/AudioSource.hx

@@ -80,6 +80,11 @@ class AudioSource
 	**/
 	public var position(get, set):Vector4;
 
+	/**
+		The stereo pan of the audio source.
+	**/
+	public var pan(get, set):Float;
+
 	/**
 		The latency of the audio source.
 	**/
@@ -229,6 +234,16 @@ class AudioSource
 		return __backend.setPosition(value);
 	}
 
+	@:noCompletion inline private function get_pan():Float
+	{
+		return __backend.getPan();
+	}
+
+	@:noCompletion inline private function set_pan(value:Float):Float
+	{
+		return __backend.setPan(value);
+	}
+
 	@:noCompletion inline private function get_latency():Float
 	{
 		return __backend.getLatency();

source/openfl/media/SoundChannel.hx

@@ -273,13 +273,9 @@ import lime.media.openal.AL;
 			if (__isValid)
 			{
 				#if lime
+				// TODO: implement SoundTransform.leftToRight, etc. with Native setAngles?
 				__source.gain = volume;
-
-				var position = __source.position;
-				position.x = pan;
-				position.z = -1 * Math.sqrt(1 - Math.pow(pan, 2));
-				__source.position = position;
-
+				__source.pan = pan;
 				return value;
 				#end
 			}