Expose AudioServer stream playback functions

Expose `AudioServer::start_playback_stream`
Expose `AudioServer::stop_playback_stream`
Move `AudioStreamPlayer::MixTarget` to `AudioServer`

Author: Spartan322

doc/classes/AudioServer.xml

@@ -359,6 +359,25 @@
 				If [param active] is [code]false[/code], stops the input stream if it is running.
 			</description>
 		</method>
+		<method name="start_playback_stream">
+			<return type="void" />
+			<param index="0" name="playback" type="AudioStreamPlayback" />
+			<param index="1" name="bus" type="StringName" />
+			<param index="2" name="volume_db_offset" type="float" default="0" />
+			<param index="3" name="mix_target" type="int" enum="AudioServer.MixTarget" default="0" />
+			<param index="4" name="start_time" type="float" default="0" />
+			<param index="5" name="pitch_scale" type="float" default="1" />
+			<description>
+				Plays [param playback] on the [param bus] audio bus from beginning, or from given [param start_time] in seconds.
+			</description>
+		</method>
+		<method name="stop_playback_stream">
+			<return type="void" />
+			<param index="0" name="playback" type="AudioStreamPlayback" />
+			<description>
+				Stops the [AudioStreamPlayback].
+			</description>
+		</method>
 		<method name="swap_bus_effects">
 			<return type="void" />
 			<param index="0" name="bus_idx" type="int" />
@@ -432,5 +451,14 @@
 		<constant name="PLAYBACK_TYPE_MAX" value="3" enum="PlaybackType" experimental="">
 			Represents the size of the [enum PlaybackType] enum.
 		</constant>
+		<constant name="MIX_TARGET_STEREO" value="0" enum="MixTarget">
+			The audio will be played only on the first channel. This is the default.
+		</constant>
+		<constant name="MIX_TARGET_SURROUND" value="1" enum="MixTarget">
+			The audio will be played on all surround channels.
+		</constant>
+		<constant name="MIX_TARGET_CENTER" value="2" enum="MixTarget">
+			The audio will be played on the second channel, which is usually the center.
+		</constant>
 	</constants>
 </class>

doc/classes/AudioStreamPlayer.xml

@@ -69,7 +69,7 @@
 		<member name="max_polyphony" type="int" setter="set_max_polyphony" getter="get_max_polyphony" default="1">
 			The maximum number of sounds this node can play at the same time. Calling [method play] after this value is reached will cut off the oldest sounds.
 		</member>
-		<member name="mix_target" type="int" setter="set_mix_target" getter="get_mix_target" enum="AudioStreamPlayer.MixTarget" default="0">
+		<member name="mix_target" type="int" setter="set_mix_target" getter="get_mix_target" enum="AudioServer.MixTarget" default="0">
 			The mix target channels. Has no effect when two speakers or less are detected (see [enum AudioServer.SpeakerMode]).
 		</member>
 		<member name="pitch_scale" type="float" setter="set_pitch_scale" getter="get_pitch_scale" default="1.0">
@@ -105,13 +105,13 @@
 		</signal>
 	</signals>
 	<constants>
-		<constant name="MIX_TARGET_STEREO" value="0" enum="MixTarget">
+		<constant name="MIX_TARGET_STEREO" value="0" enum="MixTarget" deprecated="Use [constant AudioServer.MIX_TARGET_STEREO] instead.">
 			The audio will be played only on the first channel. This is the default.
 		</constant>
-		<constant name="MIX_TARGET_SURROUND" value="1" enum="MixTarget">
+		<constant name="MIX_TARGET_SURROUND" value="1" enum="MixTarget" deprecated="Use [constant AudioServer.MIX_TARGET_SURROUND] instead.">
 			The audio will be played on all surround channels.
 		</constant>
-		<constant name="MIX_TARGET_CENTER" value="2" enum="MixTarget">
+		<constant name="MIX_TARGET_CENTER" value="2" enum="MixTarget" deprecated="Use [constant AudioServer.MIX_TARGET_CENTER] instead.">
 			The audio will be played on the second channel, which is usually the center.
 		</constant>
 	</constants>

scene/audio/audio_stream_player.compat.inc

@@ -40,6 +40,13 @@ bool AudioStreamPlayer::_is_autoplay_enabled_bind_compat_86907() {
 
 void AudioStreamPlayer::_bind_compatibility_methods() {
 	ClassDB::bind_compatibility_method(D_METHOD("is_autoplay_enabled"), &AudioStreamPlayer::_is_autoplay_enabled_bind_compat_86907);
+
+	ClassDB::bind_compatibility_method(D_METHOD("set_mix_target", "target"), (void (AudioStreamPlayer::*)(MixTarget))&AudioStreamPlayer::set_mix_target);
+	ClassDB::bind_compatibility_method(D_METHOD("get_mix_target"), (MixTarget (AudioStreamPlayer::*)())&AudioStreamPlayer::get_mix_target);
+
+	BIND_ENUM_CONSTANT(MIX_TARGET_STEREO);
+	BIND_ENUM_CONSTANT(MIX_TARGET_SURROUND);
+	BIND_ENUM_CONSTANT(MIX_TARGET_CENTER);
 }
 
 #endif // DISABLE_DEPRECATED

scene/audio/audio_stream_player.cpp

@@ -160,11 +160,11 @@ bool AudioStreamPlayer::is_autoplay_enabled() const {
 	return internal->autoplay;
 }
 
-void AudioStreamPlayer::set_mix_target(MixTarget p_target) {
+void AudioStreamPlayer::set_mix_target(AudioServer::MixTarget p_target) {
 	mix_target = p_target;
 }
 
-AudioStreamPlayer::MixTarget AudioStreamPlayer::get_mix_target() const {
+AudioServer::MixTarget AudioStreamPlayer::get_mix_target() const {
 	return mix_target;
 }
 
@@ -181,40 +181,7 @@ bool AudioStreamPlayer::get_stream_paused() const {
 }
 
 Vector<AudioFrame> AudioStreamPlayer::_get_volume_vector() {
-	Vector<AudioFrame> volume_vector;
-	// We need at most four stereo pairs (for 7.1 systems).
-	volume_vector.resize(4);
-
-	// Initialize the volume vector to zero.
-	for (AudioFrame &channel_volume_db : volume_vector) {
-		channel_volume_db = AudioFrame(0, 0);
-	}
-
-	float volume_linear = Math::db_to_linear(internal->volume_db);
-
-	// Set the volume vector up according to the speaker mode and mix target.
-	// TODO do we need to scale the volume down when we output to more channels?
-	if (AudioServer::get_singleton()->get_speaker_mode() == AudioServer::SPEAKER_MODE_STEREO) {
-		volume_vector.write[0] = AudioFrame(volume_linear, volume_linear);
-	} else {
-		switch (mix_target) {
-			case MIX_TARGET_STEREO: {
-				volume_vector.write[0] = AudioFrame(volume_linear, volume_linear);
-			} break;
-			case MIX_TARGET_SURROUND: {
-				// TODO Make sure this is right.
-				volume_vector.write[0] = AudioFrame(volume_linear, volume_linear);
-				volume_vector.write[1] = AudioFrame(volume_linear, /* LFE= */ 1.0f);
-				volume_vector.write[2] = AudioFrame(volume_linear, volume_linear);
-				volume_vector.write[3] = AudioFrame(volume_linear, volume_linear);
-			} break;
-			case MIX_TARGET_CENTER: {
-				// TODO Make sure this is right.
-				volume_vector.write[1] = AudioFrame(volume_linear, /* LFE= */ 1.0f);
-			} break;
-		}
-	}
-	return volume_vector;
+	return AudioServer::get_singleton()->create_volume_vector(internal->volume_db, mix_target);
 }
 
 void AudioStreamPlayer::_validate_property(PropertyInfo &p_property) const {
@@ -293,10 +260,6 @@ void AudioStreamPlayer::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "playback_type", PROPERTY_HINT_ENUM, "Default,Stream,Sample"), "set_playback_type", "get_playback_type");
 
 	ADD_SIGNAL(MethodInfo("finished"));
-
-	BIND_ENUM_CONSTANT(MIX_TARGET_STEREO);
-	BIND_ENUM_CONSTANT(MIX_TARGET_SURROUND);
-	BIND_ENUM_CONSTANT(MIX_TARGET_CENTER);
 }
 
 AudioStreamPlayer::AudioStreamPlayer() {

scene/audio/audio_stream_player.h

@@ -42,16 +42,18 @@ class AudioStreamPlayer : public Node {
 	GDCLASS(AudioStreamPlayer, Node);
 
 public:
+#ifndef DISABLE_DEPRECATED
 	enum MixTarget {
 		MIX_TARGET_STEREO,
 		MIX_TARGET_SURROUND,
 		MIX_TARGET_CENTER
 	};
+#endif // DISABLE_DEPRECATED
 
 private:
 	AudioStreamPlayerInternal *internal = nullptr;
 
-	MixTarget mix_target = MIX_TARGET_STEREO;
+	AudioServer::MixTarget mix_target = AudioServer::MIX_TARGET_STEREO;
 
 	void _set_playing(bool p_enable);
 	bool _is_active() const;
@@ -100,8 +102,8 @@ class AudioStreamPlayer : public Node {
 	void set_autoplay(bool p_enable);
 	bool is_autoplay_enabled() const;
 
-	void set_mix_target(MixTarget p_target);
-	MixTarget get_mix_target() const;
+	void set_mix_target(AudioServer::MixTarget p_target);
+	AudioServer::MixTarget get_mix_target() const;
 
 	void set_stream_paused(bool p_pause);
 	bool get_stream_paused() const;
@@ -116,4 +118,6 @@ class AudioStreamPlayer : public Node {
 	~AudioStreamPlayer();
 };
 
+#ifndef DISABLE_DEPRECATED
 VARIANT_ENUM_CAST(AudioStreamPlayer::MixTarget)
+#endif // DISABLE_DEPRECATED

servers/audio/audio_server.cpp

@@ -1319,6 +1319,59 @@ void AudioServer::stop_playback_stream(Ref<AudioStreamPlayback> p_playback) {
 	} while (!playback_node->state.compare_exchange_strong(old_state, new_state));
 }
 
+Vector<AudioFrame> AudioServer::create_volume_vector(float p_volume_db, MixTarget p_mix_target) const {
+	Vector<AudioFrame> volume_vector;
+	// We need at most four stereo pairs (for 7.1 systems).
+	volume_vector.resize(4);
+
+	// Initialize the volume vector to zero.
+	for (AudioFrame &channel_volume_db : volume_vector) {
+		channel_volume_db = AudioFrame(0, 0);
+	}
+
+	float volume_linear = Math::db_to_linear(p_volume_db);
+
+	// Set the volume vector up according to the speaker mode and mix target.
+	// TODO do we need to scale the volume down when we output to more channels?
+	if (get_speaker_mode() == AudioServer::SPEAKER_MODE_STEREO) {
+		volume_vector.write[0] = AudioFrame(volume_linear, volume_linear);
+	} else {
+		switch (p_mix_target) {
+			case MIX_TARGET_STEREO: {
+				volume_vector.write[0] = AudioFrame(volume_linear, volume_linear);
+			} break;
+			case MIX_TARGET_SURROUND: {
+				// TODO Make sure this is right.
+				volume_vector.write[0] = AudioFrame(volume_linear, volume_linear);
+				volume_vector.write[1] = AudioFrame(volume_linear, /* LFE= */ 1.0f);
+				volume_vector.write[2] = AudioFrame(volume_linear, volume_linear);
+				volume_vector.write[3] = AudioFrame(volume_linear, volume_linear);
+			} break;
+			case MIX_TARGET_CENTER: {
+				// TODO Make sure this is right.
+				volume_vector.write[1] = AudioFrame(volume_linear, /* LFE= */ 1.0f);
+			} break;
+		}
+	}
+
+	return volume_vector;
+}
+
+void AudioServer::_start_playback_stream(Ref<AudioStreamPlayback> p_playback, const StringName &p_bus, float p_volume_db_offset, MixTarget p_mix_target, float p_start_time, float p_pitch_scale) {
+	ERR_FAIL_COND(p_playback.is_null());
+
+	Vector<AudioFrame> volume_vector = create_volume_vector(p_volume_db_offset, p_mix_target);
+	start_playback_stream(p_playback, p_bus, volume_vector, p_start_time, p_pitch_scale);
+
+	if (p_playback->get_is_sample() && p_playback->get_sample_playback().is_valid()) {
+		Ref<AudioSamplePlayback> sample_playback = p_playback->get_sample_playback();
+		sample_playback->offset = p_start_time;
+		sample_playback->bus = p_bus;
+		sample_playback->volume_vector = volume_vector;
+		start_sample_playback(sample_playback);
+	}
+}
+
 void AudioServer::set_playback_bus_exclusive(Ref<AudioStreamPlayback> p_playback, const StringName &p_bus, Vector<AudioFrame> p_volumes) {
 	ERR_FAIL_COND(p_volumes.size() != MAX_CHANNELS_PER_BUS);
 
@@ -2113,6 +2166,9 @@ void AudioServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("is_stream_registered_as_sample", "stream"), &AudioServer::is_stream_registered_as_sample);
 	ClassDB::bind_method(D_METHOD("register_stream_as_sample", "stream"), &AudioServer::register_stream_as_sample);
 
+	ClassDB::bind_method(D_METHOD("start_playback_stream", "playback", "bus", "volume_db_offset", "mix_target", "start_time", "pitch_scale"), &AudioServer::_start_playback_stream, DEFVAL(0), DEFVAL(MIX_TARGET_STEREO), DEFVAL(0), DEFVAL(1));
+	ClassDB::bind_method(D_METHOD("stop_playback_stream", "playback"), &AudioServer::stop_playback_stream);
+
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "bus_count"), "set_bus_count", "get_bus_count");
 	ADD_PROPERTY(PropertyInfo(Variant::STRING, "output_device"), "set_output_device", "get_output_device");
 	ADD_PROPERTY(PropertyInfo(Variant::STRING, "input_device"), "set_input_device", "get_input_device");
@@ -2133,6 +2189,10 @@ void AudioServer::_bind_methods() {
 	BIND_ENUM_CONSTANT(PLAYBACK_TYPE_STREAM);
 	BIND_ENUM_CONSTANT(PLAYBACK_TYPE_SAMPLE);
 	BIND_ENUM_CONSTANT(PLAYBACK_TYPE_MAX);
+
+	BIND_ENUM_CONSTANT(MIX_TARGET_STEREO);
+	BIND_ENUM_CONSTANT(MIX_TARGET_SURROUND);
+	BIND_ENUM_CONSTANT(MIX_TARGET_CENTER);
 }
 
 AudioServer::AudioServer() {

servers/audio/audio_server.h

@@ -196,6 +196,12 @@ class AudioServer : public Object {
 		PLAYBACK_TYPE_MAX
 	};
 
+	enum MixTarget {
+		MIX_TARGET_STEREO,
+		MIX_TARGET_SURROUND,
+		MIX_TARGET_CENTER
+	};
+
 	enum {
 		AUDIO_DATA_INVALID_ID = -1,
 		MAX_CHANNELS_PER_BUS = 4,
@@ -436,6 +442,9 @@ class AudioServer : public Object {
 	void start_playback_stream(Ref<AudioStreamPlayback> p_playback, const HashMap<StringName, Vector<AudioFrame>> &p_bus_volumes, float p_start_time = 0, float p_pitch_scale = 1, float p_highshelf_gain = 0, float p_attenuation_cutoff_hz = 0);
 	void stop_playback_stream(Ref<AudioStreamPlayback> p_playback);
 
+	Vector<AudioFrame> create_volume_vector(float p_volume_db, MixTarget p_mix_target) const;
+	void _start_playback_stream(Ref<AudioStreamPlayback> p_playback, const StringName &p_bus, float p_volume_db_offset = 0, MixTarget p_mix_target = MIX_TARGET_STEREO, float p_start_time = 0, float p_pitch_scale = 1);
+
 	void set_playback_bus_exclusive(Ref<AudioStreamPlayback> p_playback, const StringName &p_bus, Vector<AudioFrame> p_volumes);
 	void set_playback_bus_volumes_linear(Ref<AudioStreamPlayback> p_playback, const HashMap<StringName, Vector<AudioFrame>> &p_bus_volumes);
 	void set_playback_all_bus_volumes_linear(Ref<AudioStreamPlayback> p_playback, Vector<AudioFrame> p_volumes);
@@ -526,6 +535,7 @@ class AudioServer : public Object {
 
 VARIANT_ENUM_CAST(AudioServer::SpeakerMode)
 VARIANT_ENUM_CAST(AudioServer::PlaybackType)
+VARIANT_ENUM_CAST(AudioServer::MixTarget)
 
 class AudioBusLayout : public Resource {
 	GDCLASS(AudioBusLayout, Resource);