godot-cpp

[!WARNING]

This repository's master branch is only usable with GDExtension from Godot's master branch.

For users of stable branches, switch to the branch matching your target Godot version:

• 4.2
• 4.1
• 4.0

Or check out the Git tag matching your Godot version (e.g. godot-4.1.1-stable).

For GDNative users (Godot 3.x), switch to the 3.x or the 3.5 branch.

This repository contains the C++ bindings for the Godot Engine's GDExtensions API.

• Versioning
• Compatibility
• Contributing
• Getting started
• Examples and templates

Versioning

This repositories follows the same branch versioning as the main Godot Engine repository:

• master tracks the current GDExtension development branch for the next Godot 4.x minor release.
• 3.x tracks the development of the GDNative plugin for the next 3.x minor release.
• Other versioned branches (e.g. 4.0, 3.5) track the latest stable release in the corresponding branch.

Stable releases are also tagged on this repository: Tags.

For any project built against a stable release of Godot, we recommend using this repository as a Git submodule, checking out the specific tag matching your Godot version.

As the master branch of Godot is constantly getting updated, if you are using godot-cpp against a more current version of Godot, see the instructions in the gdextension folder to update the relevant files.

Compatibility

Due to the intricacies of working with ABIs, compatibility with GDExtension is not as strictly guaranteed as with GDScript or C#. Current limitations in the GDExtension system may also require compatibility-breaking changes to be lifted. This applies to both the GDExtension interface header, the API JSON, and this first-party godot-cpp extension.

In practice, this means that GDExtension compatibility can occasionally break across minor Godot releases. Be sure to read the Migrating guide for your current Godot version when running into issues with installing GDExtensions.

Some compatibility breakage is to be expected as GDExtension and godot-cpp get more used, documented, and critical issues get resolved. See the Godot issue tracker and the godot-cpp issue tracker for a list of known issues, and be sure to provide feedback on issues and PRs which affect your use of this extension.

Contributing

We greatly appreciate help in maintaining and extending this project. If you wish to help out, ensure you have an account on GitHub and create a "fork" of this repository. See Pull request workflow for instructions.

Please install clang-format and copy the files in misc/hooks into .git/hooks so formatting is done before your changes are submitted.

Getting started

You need the same C++ pre-requisites installed that are required for the godot repository. Follow the official build instructions for your target platform.

Getting started with GDExtensions is a bit similar to what it was for 3.x but also a bit different.

This new approach is much more akin to how core Godot modules are structured.

Compiling this repository generates a static library to be linked with your shared lib, just like before.

To use the shared lib in your Godot project you'll need a .gdextension file, which replaces what was the .gdnlib before. See example.gdextension used in the test project:

[configuration]

entry_symbol = "example_library_init"
compatibility_minimum = "4.1"

[libraries]

macos.debug = "res://bin/libgdexample.macos.debug.framework"
macos.release = "res://bin/libgdexample.macos.release.framework"
windows.debug.x86_64 = "res://bin/libgdexample.windows.debug.x86_64.dll"
windows.release.x86_64 = "res://bin/libgdexample.windows.release.x86_64.dll"
linux.debug.x86_64 = "res://bin/libgdexample.linux.debug.x86_64.so"
linux.release.x86_64 = "res://bin/libgdexample.linux.release.x86_64.so"
# Repeat for other architectures to support arm64, rv64, etc.

The entry_symbol is the name of the function that initializes your library. It should be similar to following layout:

extern "C" {

// Initialization.

GDExtensionBool GDE_EXPORT example_library_init(GDExtensionInterfaceGetProcAddress p_get_proc_address, GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization) {
	godot::GDExtensionBinding::InitObject init_obj(p_get_proc_address, p_library, r_initialization);

	init_obj.register_initializer(initialize_example_module);
	init_obj.register_terminator(uninitialize_example_module);
	init_obj.set_minimum_library_initialization_level(MODULE_INITIALIZATION_LEVEL_SCENE);

	return init_obj.init();
}
}

The initialize_example_module() should register the classes in ClassDB, very like a Godot module would do.

using namespace godot;
void initialize_example_module(ModuleInitializationLevel p_level) {
	if (p_level != MODULE_INITIALIZATION_LEVEL_SCENE) {
		return;
	}
	GDREGISTER_CLASS(Example);
}

Any node and resource you register will be available in the corresponding Create... dialog. Any class will be available to scripting as well.

Examples and templates

See the godot-cpp-template project for a generic reusable template.

Or checkout the code for the Summator example as shown in the official documentation.