redot-cpp

Warning

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

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

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

Versioning

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

• master tracks the current GDExtension development branch for the next Redot 4.x minor release.
• Other versioned branches (e.g. 4.3) 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 Redot, we recommend using this repository as a Git submodule, checking out the specific tag matching your Redot version.

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

Compatibility

Warning

The GDExtension API is brand new since Godot 4.0, and is still considered in beta stage, despite Redot 4.3 itself being released.

This applies to both the GDExtension interface header, the API JSON, and this first-party redot-cpp extension.

Some compatibility breakage is to be expected as GDExtension and redot-cpp get more used, documented, and critical issues get resolved. See the Redot issue tracker, the Godot issue tracker, the godot-cpp issue tracker, and the redot-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 redot-engine repository. Follow the official build instructions for your target platform.

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

This new approach is much more akin to how core Redot 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 Redot 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 Redot 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 redot-cpp-template project for a generic reusable template.

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