Add Listener2D

doc/classes/Listener.xml

@@ -5,7 +5,6 @@
 	</brief_description>
 	<description>
 		Once added to the scene tree and enabled using [method make_current], this node will override the location sounds are heard from. This can be used to listen from a location different from the [Camera].
-		[b]Note:[/b] There is no 2D equivalent for this node yet.
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/Listener2D.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="Listener2D" inherits="Node2D" version="3.4">
+	<brief_description>
+		Overrides the location sounds are heard from.
+	</brief_description>
+	<description>
+		Once added to the scene tree and enabled using [method make_current], this node will override the location sounds are heard from. Only one [Listener2D] can be current. Using [method make_current] will disable the previous [Listener2D].
+		If there is no active [Listener2D] in the current [Viewport], center of the screen will be used as a hearing point for the audio. [Listener2D] needs to be inside [SceneTree] to function.
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="clear_current">
+			<return type="void" />
+			<description>
+				Disables the [Listener2D]. If it's not set as current, this method will have no effect.
+			</description>
+		</method>
+		<method name="is_current" qualifiers="const">
+			<return type="bool" />
+			<description>
+				Returns [code]true[/code] if this [Listener2D] is currently active.
+			</description>
+		</method>
+		<method name="make_current">
+			<return type="void" />
+			<description>
+				Makes the [Listener2D] active, setting it as the hearing point for the sounds. If there is already another active [Listener2D], it will be disabled.
+				This method will have no effect if the [Listener2D] is not added to [SceneTree].
+			</description>
+		</method>
+	</methods>
+	<constants>
+	</constants>
+</class>

scene/2d/audio_stream_player_2d.cpp

@@ -32,6 +32,7 @@
 
 #include "core/engine.h"
 #include "scene/2d/area_2d.h"
+#include "scene/2d/listener_2d.h"
 #include "scene/main/viewport.h"
 
 void AudioStreamPlayer2D::_mix_audio() {
@@ -208,13 +209,21 @@ void AudioStreamPlayer2D::_notification(int p_what) {
 				Viewport *vp = E->get();
 				if (vp->is_audio_listener_2d()) {
 					//compute matrix to convert to screen
-					Transform2D to_screen = vp->get_global_canvas_transform() * vp->get_canvas_transform();
 					Vector2 screen_size = vp->get_visible_rect().size;
+					Vector2 listener_in_global;
+					Vector2 relative_to_listener;
+
+					Listener2D *listener = vp->get_listener_2d();
+					if (listener) {
+						listener_in_global = listener->get_global_position();
+						relative_to_listener = global_pos - listener_in_global;
+					} else {
+						Transform2D to_listener = vp->get_global_canvas_transform() * vp->get_canvas_transform();
+						listener_in_global = to_listener.affine_inverse().xform(screen_size * 0.5);
+						relative_to_listener = to_listener.xform(global_pos) - screen_size * 0.5;
+					}
 
-					//screen in global is used for attenuation
-					Vector2 screen_in_global = to_screen.affine_inverse().xform(screen_size * 0.5);
-
-					float dist = global_pos.distance_to(screen_in_global); //distance to screen center
+					float dist = global_pos.distance_to(listener_in_global); // Distance to listener, or screen if none.
 
 					if (dist > max_distance) {
 						continue; //can't hear this sound in this viewport
@@ -223,10 +232,7 @@ void AudioStreamPlayer2D::_notification(int p_what) {
 					float multiplier = Math::pow(1.0f - dist / max_distance, attenuation);
 					multiplier *= Math::db2linear(volume_db); //also apply player volume!
 
-					//point in screen is used for panning
-					Vector2 point_in_screen = to_screen.xform(global_pos);
-
-					float pan = CLAMP(point_in_screen.x / screen_size.width, 0.0, 1.0);
+					float pan = CLAMP((relative_to_listener.x + screen_size.x * 0.5) / screen_size.x, 0.0, 1.0);
 
 					float l = 1.0 - pan;
 					float r = pan;

scene/2d/listener_2d.cpp

@@ -0,0 +1,112 @@
+/*************************************************************************/
+/*  listener_2d.cpp                                                      */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "listener_2d.h"
+
+bool Listener2D::_set(const StringName &p_name, const Variant &p_value) {
+	if (p_name == "current") {
+		if (p_value.operator bool()) {
+			make_current();
+		} else {
+			clear_current();
+		}
+	} else {
+		return false;
+	}
+	return true;
+}
+
+bool Listener2D::_get(const StringName &p_name, Variant &r_ret) const {
+	if (p_name == "current") {
+		if (is_inside_tree() && get_tree()->is_node_being_edited(this)) {
+			r_ret = current;
+		} else {
+			r_ret = is_current();
+		}
+	} else {
+		return false;
+	}
+	return true;
+}
+
+void Listener2D::_get_property_list(List<PropertyInfo> *p_list) const {
+	p_list->push_back(PropertyInfo(Variant::BOOL, "current"));
+}
+
+void Listener2D::_notification(int p_what) {
+	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE: {
+			if (!get_tree()->is_node_being_edited(this) && current) {
+				make_current();
+			}
+		} break;
+		case NOTIFICATION_EXIT_TREE: {
+			if (!get_tree()->is_node_being_edited(this)) {
+				if (is_current()) {
+					clear_current();
+					current = true; // Keep it true.
+				} else {
+					current = false;
+				}
+			}
+		} break;
+	}
+}
+
+void Listener2D::make_current() {
+	current = true;
+	if (!is_inside_tree()) {
+		return;
+	}
+	get_viewport()->_listener_2d_set(this);
+}
+
+void Listener2D::clear_current() {
+	current = false;
+	if (!is_inside_tree()) {
+		return;
+	}
+	get_viewport()->_listener_2d_remove(this);
+}
+
+bool Listener2D::is_current() const {
+	if (is_inside_tree() && !get_tree()->is_node_being_edited(this)) {
+		return get_viewport()->get_listener_2d() == this;
+	} else {
+		return current;
+	}
+	return false;
+}
+
+void Listener2D::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("make_current"), &Listener2D::make_current);
+	ClassDB::bind_method(D_METHOD("clear_current"), &Listener2D::clear_current);
+	ClassDB::bind_method(D_METHOD("is_current"), &Listener2D::is_current);
+}

scene/2d/listener_2d.h

@@ -0,0 +1,61 @@
+/*************************************************************************/
+/*  listener_2d.h                                                        */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef LISTENER_2D_H
+#define LISTENER_2D_H
+
+#include "scene/2d/node_2d.h"
+#include "scene/main/viewport.h"
+
+class Listener2D : public Node2D {
+	GDCLASS(Listener2D, Node2D);
+
+private:
+	bool current = false;
+
+	friend class Viewport;
+
+protected:
+	void _update_listener();
+
+	bool _set(const StringName &p_name, const Variant &p_value);
+	bool _get(const StringName &p_name, Variant &r_ret) const;
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+	void _notification(int p_what);
+
+	static void _bind_methods();
+
+public:
+	void make_current();
+	void clear_current();
+	bool is_current() const;
+};
+
+#endif

scene/main/viewport.cpp

@@ -35,6 +35,7 @@
 #include "core/os/os.h"
 #include "core/project_settings.h"
 #include "scene/2d/collision_object_2d.h"
+#include "scene/2d/listener_2d.cpp"
 #include "scene/3d/camera.h"
 #include "scene/3d/collision_object.h"
 #include "scene/3d/listener.h"
@@ -783,14 +784,17 @@ void Viewport::set_as_audio_listener_2d(bool p_enable) {
 	}
 
 	audio_listener_2d = p_enable;
-
 	_update_listener_2d();
 }
 
 bool Viewport::is_audio_listener_2d() const {
 	return audio_listener_2d;
 }
 
+Listener2D *Viewport::get_listener_2d() const {
+	return listener_2d;
+}
+
 void Viewport::enable_canvas_transform_override(bool p_enable) {
 	if (override_canvas_transform == p_enable) {
 		return;
@@ -977,6 +981,21 @@ void Viewport::_camera_make_next_current(Camera *p_exclude) {
 }
 #endif
 
+void Viewport::_listener_2d_set(Listener2D *p_listener) {
+	if (listener_2d == p_listener) {
+		return;
+	} else if (listener_2d) {
+		listener_2d->clear_current();
+	}
+	listener_2d = p_listener;
+}
+
+void Viewport::_listener_2d_remove(Listener2D *p_listener) {
+	if (listener_2d == p_listener) {
+		listener_2d = nullptr;
+	}
+}
+
 void Viewport::_canvas_layer_add(CanvasLayer *p_canvas_layer) {
 	canvas_layers.insert(p_canvas_layer);
 }

scene/main/viewport.h

@@ -40,6 +40,7 @@
 class Camera;
 class Camera2D;
 class Listener;
+class Listener2D;
 class Control;
 class CanvasItem;
 class CanvasLayer;
@@ -180,6 +181,7 @@ class Viewport : public Node {
 
 	Camera *camera;
 	Set<Camera *> cameras;
+	Listener2D *listener_2d = nullptr;
 	Set<CanvasLayer *> canvas_layers;
 
 	RID viewport;
@@ -400,6 +402,10 @@ class Viewport : public Node {
 	void _camera_remove(Camera *p_camera);
 	void _camera_make_next_current(Camera *p_exclude);
 
+	friend class Listener2D;
+	void _listener_2d_set(Listener2D *p_listener);
+	void _listener_2d_remove(Listener2D *p_listener);
+
 	friend class CanvasLayer;
 	void _canvas_layer_add(CanvasLayer *p_canvas_layer);
 	void _canvas_layer_remove(CanvasLayer *p_canvas_layer);
@@ -436,6 +442,7 @@ class Viewport : public Node {
 	void set_as_audio_listener(bool p_enable);
 	bool is_audio_listener() const;
 
+	Listener2D *get_listener_2d() const;
 	void set_as_audio_listener_2d(bool p_enable);
 	bool is_audio_listener_2d() const;
 

scene/register_scene_types.cpp

@@ -47,6 +47,7 @@
 #include "scene/2d/light_2d.h"
 #include "scene/2d/light_occluder_2d.h"
 #include "scene/2d/line_2d.h"
+#include "scene/2d/listener_2d.h"
 #include "scene/2d/mesh_instance_2d.h"
 #include "scene/2d/multimesh_instance_2d.h"
 #include "scene/2d/navigation_2d.h"
@@ -597,6 +598,7 @@ void register_scene_types() {
 	OS::get_singleton()->yield(); //may take time to init
 
 	ClassDB::register_class<Camera2D>();
+	ClassDB::register_class<Listener2D>();
 	ClassDB::register_virtual_class<Joint2D>();
 	ClassDB::register_class<PinJoint2D>();
 	ClassDB::register_class<GrooveJoint2D>();