Move Godot Physics 2D into a module; add dummy 2D physics server

COPYRIGHT.txt

@@ -63,6 +63,11 @@ Copyright: 2011, Ole Kniemeyer, MAXON, www.maxon.net
  2007-2014, Juan Linietsky, Ariel Manzur
 License: Expat and Zlib
 
+Files: ./modules/godot_physics_2d/godot_joints_2d.cpp
+Comment: Chipmunk2D Joint Constraints
+Copyright: 2007, Scott Lembcke
+License: Expat
+
 Files: ./modules/godot_physics_3d/gjk_epa.cpp
  ./modules/godot_physics_3d/joints/godot_generic_6dof_joint_3d.cpp
  ./modules/godot_physics_3d/joints/godot_generic_6dof_joint_3d.h
@@ -126,11 +131,6 @@ Copyright: 2001, Robert Penner
  2007-2014, Juan Linietsky, Ariel Manzur
 License: Expat
 
-Files: ./servers/physics_2d/godot_joints_2d.cpp
-Comment: Chipmunk2D Joint Constraints
-Copyright: 2007, Scott Lembcke
-License: Expat
-
 Files: ./servers/rendering/renderer_rd/shaders/ss_effects_downsample.glsl
  ./servers/rendering/renderer_rd/shaders/ssao_blur.glsl
  ./servers/rendering/renderer_rd/shaders/ssao_importance_map.glsl

doc/classes/ProjectSettings.xml

@@ -2215,6 +2215,7 @@
 		<member name="physics/2d/physics_engine" type="String" setter="" getter="" default="&quot;DEFAULT&quot;">
 			Sets which physics engine to use for 2D physics.
 			"DEFAULT" and "GodotPhysics2D" are the same, as there is currently no alternative 2D physics server implemented.
+			"Dummy" is a 2D physics server that does nothing and returns only dummy values, effectively disabling all 2D physics functionality.
 		</member>
 		<member name="physics/2d/run_on_separate_thread" type="bool" setter="" getter="" default="false">
 			If [code]true[/code], the 2D physics server runs on a separate thread, making better use of multi-core CPUs. If [code]false[/code], the 2D physics server runs on the main thread. Running the physics server on a separate thread can increase performance, but restricts API access to only physics process.

main/main.cpp

@@ -80,6 +80,7 @@
 #include "servers/navigation_server_2d.h"
 #include "servers/navigation_server_2d_dummy.h"
 #include "servers/physics_server_2d.h"
+#include "servers/physics_server_2d_dummy.h"
 
 #ifndef _3D_DISABLED
 #include "servers/physics_server_3d.h"
@@ -340,7 +341,15 @@ void initialize_physics() {
 		// Physics server not found, Use the default physics
 		physics_server_2d = PhysicsServer2DManager::get_singleton()->new_default_server();
 	}
-	ERR_FAIL_NULL(physics_server_2d);
+
+	// Fall back to dummy if no default server has been registered.
+	if (!physics_server_2d) {
+		WARN_PRINT(vformat("Falling back to dummy PhysicsServer2D; 2D physics functionality will be disabled. If this is intended, set the %s project setting to Dummy.", PhysicsServer2DManager::setting_property_name));
+		physics_server_2d = memnew(PhysicsServer2DDummy);
+	}
+
+	// Should be impossible, but make sure it's not null.
+	ERR_FAIL_NULL_MSG(physics_server_2d, "Failed to initialize PhysicsServer2D.");
 	physics_server_2d->init();
 }
 

modules/godot_physics_2d/SCsub

@@ -0,0 +1,5 @@
+#!/usr/bin/env python
+
+Import('env')
+
+env.add_source_files(env.modules_sources, "*.cpp")

modules/godot_physics_2d/config.py

@@ -0,0 +1,6 @@
+def can_build(env, platform):
+    return True
+
+
+def configure(env):
+    pass

modules/godot_physics_2d/register_types.cpp

@@ -0,0 +1,61 @@
+/**************************************************************************/
+/*  register_types.cpp                                                    */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* 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 "register_types.h"
+
+#include "godot_physics_server_2d.h"
+#include "servers/physics_server_2d.h"
+#include "servers/physics_server_2d_wrap_mt.h"
+
+static PhysicsServer2D *_createGodotPhysics2DCallback() {
+#ifdef THREADS_ENABLED
+	bool using_threads = GLOBAL_GET("physics/2d/run_on_separate_thread");
+#else
+	bool using_threads = false;
+#endif
+
+	PhysicsServer2D *physics_server_2d = memnew(GodotPhysicsServer2D(using_threads));
+
+	return memnew(PhysicsServer2DWrapMT(physics_server_2d, using_threads));
+}
+
+void initialize_godot_physics_2d_module(ModuleInitializationLevel p_level) {
+	if (p_level != MODULE_INITIALIZATION_LEVEL_SERVERS) {
+		return;
+	}
+	PhysicsServer2DManager::get_singleton()->register_server("GodotPhysics2D", callable_mp_static(_createGodotPhysics2DCallback));
+	PhysicsServer2DManager::get_singleton()->set_default_server("GodotPhysics2D");
+}
+
+void uninitialize_godot_physics_2d_module(ModuleInitializationLevel p_level) {
+	if (p_level != MODULE_INITIALIZATION_LEVEL_SERVERS) {
+		return;
+	}
+}

modules/godot_physics_2d/register_types.h

@@ -0,0 +1,39 @@
+/**************************************************************************/
+/*  register_types.h                                                      */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* 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 GODOT_PHYSICS_2D_REGISTER_TYPES_H
+#define GODOT_PHYSICS_2D_REGISTER_TYPES_H
+
+#include "modules/register_module_types.h"
+
+void initialize_godot_physics_2d_module(ModuleInitializationLevel p_level);
+void uninitialize_godot_physics_2d_module(ModuleInitializationLevel p_level);
+
+#endif // GODOT_PHYSICS_2D_REGISTER_TYPES_H

scene/2d/physics/shape_cast_2d.cpp

@@ -34,7 +34,7 @@
 #include "scene/2d/physics/collision_object_2d.h"
 #include "scene/2d/physics/physics_body_2d.h"
 #include "scene/resources/2d/circle_shape_2d.h"
-#include "servers/physics_2d/godot_physics_server_2d.h"
+#include "servers/physics_server_2d.h"
 
 void ShapeCast2D::set_target_position(const Vector2 &p_point) {
 	target_position = p_point;

scu_builders.py

@@ -322,6 +322,7 @@ def generate_scu_files(max_includes_per_scu):
     process_folder(["modules/openxr"], ["register_types"])
     process_folder(["modules/openxr/action_map"])
     process_folder(["modules/openxr/editor"])
+    process_folder(["modules/godot_physics_2d"])
     process_folder(["modules/godot_physics_3d"])
     process_folder(["modules/godot_physics_3d/joints"])
 
@@ -350,7 +351,6 @@ def generate_scu_files(max_includes_per_scu):
     process_folder(["servers/rendering/renderer_rd/effects"])
     process_folder(["servers/rendering/renderer_rd/environment"])
     process_folder(["servers/rendering/renderer_rd/storage_rd"])
-    process_folder(["servers/physics_2d"])
     process_folder(["servers/audio"])
     process_folder(["servers/audio/effects"])
 

servers/SCsub

@@ -25,8 +25,6 @@ SConscript("navigation/SCsub")
 SConscript("rendering/SCsub")
 SConscript("text/SCsub")
 
-SConscript("physics_2d/SCsub")
-
 if not env["disable_3d"]:
     env.add_source_files(env.servers_sources, "physics_server_3d.cpp")
     env.add_source_files(env.servers_sources, "physics_server_3d_wrap_mt.cpp")

servers/physics_server_2d.cpp

@@ -972,7 +972,9 @@ String PhysicsServer2DManager::get_server_name(int p_id) {
 }
 
 PhysicsServer2D *PhysicsServer2DManager::new_default_server() {
-	ERR_FAIL_COND_V(default_server_id == -1, nullptr);
+	if (default_server_id == -1) {
+		return nullptr;
+	}
 	Variant ret;
 	Callable::CallError ce;
 	physics_2d_servers[default_server_id].create_callback.callp(nullptr, 0, ret, ce);