Implement blending audio feature to AnimationTree

doc/classes/Animation.xml

@@ -104,6 +104,13 @@
 				[param stream] is the [AudioStream] resource to play. [param start_offset] is the number of seconds cut off at the beginning of the audio stream, while [param end_offset] is at the ending.
 			</description>
 		</method>
+		<method name="audio_track_is_use_blend" qualifiers="const">
+			<return type="bool" />
+			<param index="0" name="track_idx" type="int" />
+			<description>
+				Returns [code]true[/code] if the track at [code]idx[/code] will be blended with other animations.
+			</description>
+		</method>
 		<method name="audio_track_set_key_end_offset">
 			<return type="void" />
 			<param index="0" name="track_idx" type="int" />
@@ -131,6 +138,14 @@
 				Sets the stream of the key identified by [param key_idx] to value [param stream]. The [param track_idx] must be the index of an Audio Track.
 			</description>
 		</method>
+		<method name="audio_track_set_use_blend">
+			<return type="void" />
+			<param index="0" name="track_idx" type="int" />
+			<param index="1" name="enable" type="bool" />
+			<description>
+				Sets whether the track will be blended with other animations. If [code]true[/code], the audio playback volume changes depending on the blend value.
+			</description>
+		</method>
 		<method name="bezier_track_get_key_in_handle" qualifiers="const">
 			<return type="Vector2" />
 			<param index="0" name="track_idx" type="int" />

doc/classes/AnimationPlayer.xml

@@ -232,6 +232,10 @@
 		<member name="assigned_animation" type="String" setter="set_assigned_animation" getter="get_assigned_animation">
 			If playing, the the current animation's key, otherwise, the animation last played. When set, this changes the animation, but will not play it unless already playing. See also [member current_animation].
 		</member>
+		<member name="audio_max_polyphony" type="int" setter="set_audio_max_polyphony" getter="get_audio_max_polyphony" default="32">
+			The number of possible simultaneous sounds for each of the assigned AudioStreamPlayers.
+			For example, if this value is [code]32[/code] and the animation has two audio tracks, the two [AudioStreamPlayer]s assigned can play simultaneously up to [code]32[/code] voices each.
+		</member>
 		<member name="autoplay" type="String" setter="set_autoplay" getter="get_autoplay" default="&quot;&quot;">
 			The key of the animation to play when the scene loads.
 		</member>

doc/classes/AnimationTree.xml

@@ -110,6 +110,10 @@
 		<member name="anim_player" type="NodePath" setter="set_animation_player" getter="get_animation_player" default="NodePath(&quot;&quot;)">
 			The path to the [AnimationPlayer] used for animating.
 		</member>
+		<member name="audio_max_polyphony" type="int" setter="set_audio_max_polyphony" getter="get_audio_max_polyphony" default="32">
+			The number of possible simultaneous sounds for each of the assigned AudioStreamPlayers.
+			For example, if this value is [code]32[/code] and the animation has two audio tracks, the two [AudioStreamPlayer]s assigned can play simultaneously up to [code]32[/code] voices each.
+		</member>
 		<member name="process_callback" type="int" setter="set_process_callback" getter="get_process_callback" enum="AnimationTree.AnimationProcessCallback" default="1">
 			The process mode of this [AnimationTree]. See [enum AnimationProcessCallback] for available modes.
 		</member>

doc/classes/AudioStreamPlayer.xml

@@ -28,6 +28,12 @@
 				Returns the [AudioStreamPlayback] object associated with this [AudioStreamPlayer].
 			</description>
 		</method>
+		<method name="has_stream_playback">
+			<return type="bool" />
+			<description>
+				Returns whether the [AudioStreamPlayer] can return the [AudioStreamPlayback] object or not.
+			</description>
+		</method>
 		<method name="play">
 			<return type="void" />
 			<param index="0" name="from_position" type="float" default="0.0" />

doc/classes/AudioStreamPlayer2D.xml

@@ -25,6 +25,12 @@
 				Returns the [AudioStreamPlayback] object associated with this [AudioStreamPlayer2D].
 			</description>
 		</method>
+		<method name="has_stream_playback">
+			<return type="bool" />
+			<description>
+				Returns whether the [AudioStreamPlayer] can return the [AudioStreamPlayback] object or not.
+			</description>
+		</method>
 		<method name="play">
 			<return type="void" />
 			<param index="0" name="from_position" type="float" default="0.0" />

doc/classes/AudioStreamPlayer3D.xml

@@ -25,6 +25,12 @@
 				Returns the [AudioStreamPlayback] object associated with this [AudioStreamPlayer3D].
 			</description>
 		</method>
+		<method name="has_stream_playback">
+			<return type="bool" />
+			<description>
+				Returns whether the [AudioStreamPlayer] can return the [AudioStreamPlayback] object or not.
+			</description>
+		</method>
 		<method name="play">
 			<return type="void" />
 			<param index="0" name="from_position" type="float" default="0.0" />

editor/animation_track_editor.cpp

@@ -1954,6 +1954,10 @@ void AnimationTrackEdit::_notification(int p_what) {
 					get_theme_icon(SNAME("TrackDiscrete"), SNAME("EditorIcons")),
 					get_theme_icon(SNAME("TrackCapture"), SNAME("EditorIcons"))
 				};
+				Ref<Texture2D> blend_icon[2] = {
+					get_theme_icon(SNAME("UseBlendEnable"), SNAME("EditorIcons")),
+					get_theme_icon(SNAME("UseBlendDisable"), SNAME("EditorIcons")),
+				};
 
 				int ofs = get_size().width - timeline->get_buttons_width();
 
@@ -1982,6 +1986,11 @@ void AnimationTrackEdit::_notification(int p_what) {
 					if (!animation->track_is_compressed(track) && animation->track_get_type(track) == Animation::TYPE_VALUE) {
 						draw_texture(update_icon, update_mode_rect.position);
 					}
+					if (animation->track_get_type(track) == Animation::TYPE_AUDIO) {
+						Ref<Texture2D> use_blend_icon = blend_icon[animation->audio_track_is_use_blend(track) ? 0 : 1];
+						Vector2 use_blend_icon_pos = update_mode_rect.position + (update_mode_rect.size - use_blend_icon->get_size()) / 2;
+						draw_texture(use_blend_icon, use_blend_icon_pos);
+					}
 					// Make it easier to click.
 					update_mode_rect.position.y = 0;
 					update_mode_rect.size.y = get_size().height;
@@ -1990,13 +1999,12 @@ void AnimationTrackEdit::_notification(int p_what) {
 					update_mode_rect.size.x += hsep / 2;
 
 					if (!read_only) {
-						if (animation->track_get_type(track) == Animation::TYPE_VALUE) {
+						if (animation->track_get_type(track) == Animation::TYPE_VALUE || animation->track_get_type(track) == Animation::TYPE_AUDIO) {
 							draw_texture(down_icon, Vector2(ofs, int(get_size().height - down_icon->get_height()) / 2));
 							update_mode_rect.size.x += down_icon->get_width();
 						} else if (animation->track_get_type(track) == Animation::TYPE_BEZIER) {
 							Ref<Texture2D> bezier_icon = get_theme_icon(SNAME("EditBezier"), SNAME("EditorIcons"));
 							update_mode_rect.size.x += down_icon->get_width();
-
 							update_mode_rect = Rect2();
 						} else {
 							update_mode_rect = Rect2();
@@ -2439,7 +2447,11 @@ String AnimationTrackEdit::get_tooltip(const Point2 &p_pos) const {
 	}
 
 	if (update_mode_rect.has_point(p_pos)) {
-		return TTR("Update Mode (How this property is set)");
+		if (animation->track_get_type(track) == Animation::TYPE_AUDIO) {
+			return TTR("Use Blend");
+		} else {
+			return TTR("Update Mode (How this property is set)");
+		}
 	}
 
 	if (interp_mode_rect.has_point(p_pos)) {
@@ -2641,9 +2653,14 @@ void AnimationTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 					menu->connect("id_pressed", callable_mp(this, &AnimationTrackEdit::_menu_selected));
 				}
 				menu->clear();
-				menu->add_icon_item(get_theme_icon(SNAME("TrackContinuous"), SNAME("EditorIcons")), TTR("Continuous"), MENU_CALL_MODE_CONTINUOUS);
-				menu->add_icon_item(get_theme_icon(SNAME("TrackDiscrete"), SNAME("EditorIcons")), TTR("Discrete"), MENU_CALL_MODE_DISCRETE);
-				menu->add_icon_item(get_theme_icon(SNAME("TrackCapture"), SNAME("EditorIcons")), TTR("Capture"), MENU_CALL_MODE_CAPTURE);
+				if (animation->track_get_type(track) == Animation::TYPE_AUDIO) {
+					menu->add_icon_item(get_theme_icon(SNAME("UseBlendEnable"), SNAME("EditorIcons")), TTR("Use Blend"), MENU_USE_BLEND_ENABLED);
+					menu->add_icon_item(get_theme_icon(SNAME("UseBlendDisable"), SNAME("EditorIcons")), TTR("Don't Use Blend"), MENU_USE_BLEND_DISABLED);
+				} else {
+					menu->add_icon_item(get_theme_icon(SNAME("TrackContinuous"), SNAME("EditorIcons")), TTR("Continuous"), MENU_CALL_MODE_CONTINUOUS);
+					menu->add_icon_item(get_theme_icon(SNAME("TrackDiscrete"), SNAME("EditorIcons")), TTR("Discrete"), MENU_CALL_MODE_DISCRETE);
+					menu->add_icon_item(get_theme_icon(SNAME("TrackCapture"), SNAME("EditorIcons")), TTR("Capture"), MENU_CALL_MODE_CAPTURE);
+				}
 				menu->reset_size();
 
 				Vector2 popup_pos = get_screen_position() + update_mode_rect.position + Vector2(0, update_mode_rect.size.height);
@@ -2662,7 +2679,7 @@ void AnimationTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 				menu->add_icon_item(get_theme_icon(SNAME("InterpRaw"), SNAME("EditorIcons")), TTR("Nearest"), MENU_INTERPOLATION_NEAREST);
 				menu->add_icon_item(get_theme_icon(SNAME("InterpLinear"), SNAME("EditorIcons")), TTR("Linear"), MENU_INTERPOLATION_LINEAR);
 				menu->add_icon_item(get_theme_icon(SNAME("InterpCubic"), SNAME("EditorIcons")), TTR("Cubic"), MENU_INTERPOLATION_CUBIC);
-				// Check is angle property.
+				// Check whether it is angle property.
 				AnimationPlayerEditor *ape = AnimationPlayerEditor::get_singleton();
 				if (ape) {
 					AnimationPlayer *ap = ape->get_player();
@@ -3055,6 +3072,16 @@ void AnimationTrackEdit::_menu_selected(int p_index) {
 			emit_signal(SNAME("delete_request"));
 
 		} break;
+		case MENU_USE_BLEND_ENABLED:
+		case MENU_USE_BLEND_DISABLED: {
+			bool use_blend = p_index == MENU_USE_BLEND_ENABLED;
+			EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
+			undo_redo->create_action(TTR("Change Animation Use Blend"));
+			undo_redo->add_do_method(animation.ptr(), "audio_track_set_use_blend", track, use_blend);
+			undo_redo->add_undo_method(animation.ptr(), "audio_track_set_use_blend", track, animation->audio_track_is_use_blend(track));
+			undo_redo->commit_action();
+			queue_redraw();
+		} break;
 	}
 }
 
@@ -3488,6 +3515,9 @@ void AnimationTrackEditor::_animation_track_remove_request(int p_track, Ref<Anim
 		if (p_from_animation->track_get_type(idx) == Animation::TYPE_VALUE) {
 			undo_redo->add_undo_method(p_from_animation.ptr(), "value_track_set_update_mode", idx, p_from_animation->value_track_get_update_mode(idx));
 		}
+		if (animation->track_get_type(idx) == Animation::TYPE_AUDIO) {
+			undo_redo->add_undo_method(animation.ptr(), "audio_track_set_use_blend", idx, animation->audio_track_is_use_blend(idx));
+		}
 
 		undo_redo->commit_action();
 	}
@@ -5618,6 +5648,9 @@ void AnimationTrackEditor::_edit_menu_pressed(int p_option) {
 						if (tc.track_type == Animation::TYPE_VALUE) {
 							tc.update_mode = animation->value_track_get_update_mode(idx);
 						}
+						if (tc.track_type == Animation::TYPE_AUDIO) {
+							tc.use_blend = animation->audio_track_is_use_blend(idx);
+						}
 						tc.loop_wrap = animation->track_get_interpolation_loop_wrap(idx);
 						tc.enabled = animation->track_is_enabled(idx);
 						for (int i = 0; i < animation->track_get_key_count(idx); i++) {
@@ -5662,6 +5695,9 @@ void AnimationTrackEditor::_edit_menu_pressed(int p_option) {
 				if (track_clipboard[i].track_type == Animation::TYPE_VALUE) {
 					undo_redo->add_do_method(animation.ptr(), "value_track_set_update_mode", base_track, track_clipboard[i].update_mode);
 				}
+				if (track_clipboard[i].track_type == Animation::TYPE_AUDIO) {
+					undo_redo->add_do_method(animation.ptr(), "audio_track_set_use_blend", base_track, track_clipboard[i].use_blend);
+				}
 
 				for (int j = 0; j < track_clipboard[i].keys.size(); j++) {
 					undo_redo->add_do_method(animation.ptr(), "track_insert_key", base_track, track_clipboard[i].keys[j].time, track_clipboard[i].keys[j].value, track_clipboard[i].keys[j].transition);

editor/animation_track_editor.h

@@ -220,7 +220,9 @@ class AnimationTrackEdit : public Control {
 		MENU_KEY_INSERT,
 		MENU_KEY_DUPLICATE,
 		MENU_KEY_ADD_RESET,
-		MENU_KEY_DELETE
+		MENU_KEY_DELETE,
+		MENU_USE_BLEND_ENABLED,
+		MENU_USE_BLEND_DISABLED,
 	};
 
 	AnimationTimelineEdit *timeline = nullptr;
@@ -566,6 +568,7 @@ class AnimationTrackEditor : public VBoxContainer {
 		Animation::LoopMode loop_mode = Animation::LOOP_PINGPONG;
 		bool loop_wrap = false;
 		bool enabled = false;
+		bool use_blend = false;
 
 		struct Key {
 			float time = 0;

scene/2d/audio_stream_player_2d.cpp

@@ -72,12 +72,10 @@ void AudioStreamPlayer2D::_notification(int p_what) {
 				_update_panning();
 			}
 
-			if (setplay.get() >= 0 && stream.is_valid()) {
+			if (setplayback.is_valid() && setplay.get() >= 0) {
 				active.set();
-				Ref<AudioStreamPlayback> new_playback = stream->instantiate_playback();
-				ERR_FAIL_COND_MSG(new_playback.is_null(), "Failed to instantiate playback.");
-				AudioServer::get_singleton()->start_playback_stream(new_playback, _get_actual_bus(), volume_vector, setplay.get(), pitch_scale);
-				stream_playbacks.push_back(new_playback);
+				AudioServer::get_singleton()->start_playback_stream(setplayback, _get_actual_bus(), volume_vector, setplay.get(), pitch_scale);
+				setplayback.unref();
 				setplay.set(-1);
 			}
 
@@ -255,7 +253,11 @@ void AudioStreamPlayer2D::play(float p_from_pos) {
 	if (stream->is_monophonic() && is_playing()) {
 		stop();
 	}
+	Ref<AudioStreamPlayback> stream_playback = stream->instantiate_playback();
+	ERR_FAIL_COND_MSG(stream_playback.is_null(), "Failed to instantiate playback.");
 
+	stream_playbacks.push_back(stream_playback);
+	setplayback = stream_playback;
 	setplay.set(p_from_pos);
 	active.set();
 	set_physics_process_internal(true);
@@ -390,6 +392,10 @@ bool AudioStreamPlayer2D::get_stream_paused() const {
 	return false;
 }
 
+bool AudioStreamPlayer2D::has_stream_playback() {
+	return !stream_playbacks.is_empty();
+}
+
 Ref<AudioStreamPlayback> AudioStreamPlayer2D::get_stream_playback() {
 	ERR_FAIL_COND_V_MSG(stream_playbacks.is_empty(), Ref<AudioStreamPlayback>(), "Player is inactive. Call play() before requesting get_stream_playback().");
 	return stream_playbacks[stream_playbacks.size() - 1];
@@ -458,6 +464,7 @@ void AudioStreamPlayer2D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_panning_strength", "panning_strength"), &AudioStreamPlayer2D::set_panning_strength);
 	ClassDB::bind_method(D_METHOD("get_panning_strength"), &AudioStreamPlayer2D::get_panning_strength);
 
+	ClassDB::bind_method(D_METHOD("has_stream_playback"), &AudioStreamPlayer2D::has_stream_playback);
 	ClassDB::bind_method(D_METHOD("get_stream_playback"), &AudioStreamPlayer2D::get_stream_playback);
 
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "stream", PROPERTY_HINT_RESOURCE_TYPE, "AudioStream"), "set_stream", "get_stream");

scene/2d/audio_stream_player_2d.h

@@ -56,6 +56,7 @@ class AudioStreamPlayer2D : public Node2D {
 
 	SafeFlag active{ false };
 	SafeNumeric<float> setplay{ -1.0 };
+	Ref<AudioStreamPlayback> setplayback;
 
 	Vector<AudioFrame> volume_vector;
 
@@ -129,6 +130,7 @@ class AudioStreamPlayer2D : public Node2D {
 	void set_panning_strength(float p_panning_strength);
 	float get_panning_strength() const;
 
+	bool has_stream_playback();
 	Ref<AudioStreamPlayback> get_stream_playback();
 
 	AudioStreamPlayer2D();

scene/3d/audio_stream_player_3d.cpp

@@ -284,14 +284,12 @@ void AudioStreamPlayer3D::_notification(int p_what) {
 				volume_vector = _update_panning();
 			}
 
-			if (setplay.get() >= 0 && stream.is_valid()) {
+			if (setplayback.is_valid() && setplay.get() >= 0) {
 				active.set();
-				Ref<AudioStreamPlayback> new_playback = stream->instantiate_playback();
-				ERR_FAIL_COND_MSG(new_playback.is_null(), "Failed to instantiate playback.");
 				HashMap<StringName, Vector<AudioFrame>> bus_map;
 				bus_map[_get_actual_bus()] = volume_vector;
-				AudioServer::get_singleton()->start_playback_stream(new_playback, bus_map, setplay.get(), actual_pitch_scale, linear_attenuation, attenuation_filter_cutoff_hz);
-				stream_playbacks.push_back(new_playback);
+				AudioServer::get_singleton()->start_playback_stream(setplayback, bus_map, setplay.get(), actual_pitch_scale, linear_attenuation, attenuation_filter_cutoff_hz);
+				setplayback.unref();
 				setplay.set(-1);
 			}
 
@@ -580,14 +578,21 @@ void AudioStreamPlayer3D::play(float p_from_pos) {
 	if (stream->is_monophonic() && is_playing()) {
 		stop();
 	}
+	Ref<AudioStreamPlayback> stream_playback = stream->instantiate_playback();
+	ERR_FAIL_COND_MSG(stream_playback.is_null(), "Failed to instantiate playback.");
+
+	stream_playbacks.push_back(stream_playback);
+	setplayback = stream_playback;
 	setplay.set(p_from_pos);
 	active.set();
 	set_physics_process_internal(true);
 }
 
 void AudioStreamPlayer3D::seek(float p_seconds) {
-	stop();
-	play(p_seconds);
+	if (is_playing()) {
+		stop();
+		play(p_seconds);
+	}
 }
 
 void AudioStreamPlayer3D::stop() {
@@ -783,6 +788,10 @@ bool AudioStreamPlayer3D::get_stream_paused() const {
 	return false;
 }
 
+bool AudioStreamPlayer3D::has_stream_playback() {
+	return !stream_playbacks.is_empty();
+}
+
 Ref<AudioStreamPlayback> AudioStreamPlayer3D::get_stream_playback() {
 	ERR_FAIL_COND_V_MSG(stream_playbacks.is_empty(), Ref<AudioStreamPlayback>(), "Player is inactive. Call play() before requesting get_stream_playback().");
 	return stream_playbacks[stream_playbacks.size() - 1];
@@ -875,6 +884,7 @@ void AudioStreamPlayer3D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_panning_strength", "panning_strength"), &AudioStreamPlayer3D::set_panning_strength);
 	ClassDB::bind_method(D_METHOD("get_panning_strength"), &AudioStreamPlayer3D::get_panning_strength);
 
+	ClassDB::bind_method(D_METHOD("has_stream_playback"), &AudioStreamPlayer3D::has_stream_playback);
 	ClassDB::bind_method(D_METHOD("get_stream_playback"), &AudioStreamPlayer3D::get_stream_playback);
 
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "stream", PROPERTY_HINT_RESOURCE_TYPE, "AudioStream"), "set_stream", "get_stream");

scene/3d/audio_stream_player_3d.h

@@ -69,6 +69,7 @@ class AudioStreamPlayer3D : public Node3D {
 
 	SafeFlag active{ false };
 	SafeNumeric<float> setplay{ -1.0 };
+	Ref<AudioStreamPlayback> setplayback;
 
 	AttenuationModel attenuation_model = ATTENUATION_INVERSE_DISTANCE;
 	float volume_db = 0.0;
@@ -188,6 +189,7 @@ class AudioStreamPlayer3D : public Node3D {
 	void set_panning_strength(float p_panning_strength);
 	float get_panning_strength() const;
 
+	bool has_stream_playback();
 	Ref<AudioStreamPlayback> get_stream_playback();
 
 	AudioStreamPlayer3D();