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godot-docs/tutorials/scripting/gdextension/what_is_gdextension.rst

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.. _doc_what_is_gdextension:
What is GDExtension?
====================
Introduction
------------
**GDExtension** is a Godot-specific technology that lets the engine interact with
native `shared libraries <https://en.wikipedia.org/wiki/Library_(computing)#Shared_libraries>`__
at run-time. You can use it to run native code without compiling it with the engine.
.. note:: GDExtension is *not* a scripting language and has no relation to
:ref:`GDScript <doc_gdscript>`.
Differences between GDExtension and C++ modules
-----------------------------------------------
You can use both GDExtension and :ref:`C++ modules <doc_custom_modules_in_cpp>` to
run C or C++ code in a Godot project.
They also both allow you to integrate third-party libraries into Godot. The one
you should choose depends on your needs.
.. warning::
Our long-term goal is that GDExtensions targeting an earlier version of
Godot will work in later minor versions, but not vice-versa. For example, a
GDExtension targeting Godot 4.2 should work just fine in Godot 4.3, but one
targeting Godot 4.3 won't work in Godot 4.2.
However, GDExtension is currently *experimental*, which means that we may
break compatibility in order to fix major bugs or include critical features.
For example, GDExtensions created for Godot 4.0 aren't compatible with Godot
4.1 (see :ref:`updating_your_gdextension_for_godot_4_1`).
Advantages of GDExtension
^^^^^^^^^^^^^^^^^^^^^^^^^
Unlike modules, GDExtension doesn't require compiling the engine's source code,
making it easier to distribute your work. It gives you access to most of the API
available to GDScript and C#, allowing you to code game logic with full control
regarding performance. It's ideal if you need high-performance code you'd like
to distribute as an add-on in the :ref:`asset library <doc_what_is_assetlib>`.
Also:
- GDExtension is not limited to C and C++. Thanks to :ref:`third-party bindings
<doc_what_is_gdnative_third_party_bindings>`, you can use it with many other
languages.
- You can use the same compiled GDExtension library in the editor and exported
project. With C++ modules, you have to recompile all the export templates you
plan to use if you require its functionality at run-time.
- GDExtension only requires you to compile your library, not the whole engine.
That's unlike C++ modules, which are statically compiled into the engine.
Every time you change a module, you need to recompile the engine. Even with
incremental builds, this process is slower than using GDExtension.
Advantages of C++ modules
^^^^^^^^^^^^^^^^^^^^^^^^^
We recommend :ref:`C++ modules <doc_custom_modules_in_cpp>` in cases where
GDExtension isn't enough:
- C++ modules provide deeper integration into the engine. GDExtension's access
is not as deep as static modules.
- You can use C++ modules to provide additional features in a project without
carrying native library files around. This extends to exported projects.
.. note::
If you notice that specific systems are not accessible via GDExtension
but are via custom modules, feel free to open an issue on the
`godot-cpp repository <https://github.com/godotengine/godot-cpp>`__
to discuss implementation options for exposing the missing functionality.
Supported languages
-------------------
The Godot developers officially support the following language bindings for
GDExtension:
- C++ :ref:`(tutorial) <doc_gdextension_cpp_example>`
.. note::
There are no plans to support additional languages with GDExtension officially.
That said, the community offers several bindings for other languages (see
below).
.. _doc_what_is_gdnative_third_party_bindings:
The bindings below are developed and maintained by the community:
.. Binding developers: Feel free to open a pull request to add your binding if it's well-developed enough to be used in a project.
.. Please keep languages sorted in alphabetical order.
- `D <https://github.com/godot-dlang/godot-dlang>`__
- `Haxe <https://hxgodot.github.io/>`__
- `Rust <https://github.com/godot-rust/gdextension>`__
- `Swift <https://github.com/migueldeicaza/SwiftGodot>`__
.. note::
Not all bindings mentioned here may be production-ready. Make sure to
research options thoroughly before starting a project with one of those.
Also, double-check whether the binding is compatible with the Godot version
you're using.
Version compatibility
---------------------
GDExtension add-ons compiled for a given Godot version are only guaranteed to work
with the same minor release series. For example, a GDExtension add-on compiled for
Godot 4.0 will only work with Godot 4.0, 4.0.1, 4.0.2. In addition, GDExtension is
not compatible with Godot 3.x.
GDExtension add-ons are also only compatible with engine builds that use the
level of floating-point precision the extension was compiled for. This means
that if you use a engine build with double-precision floats, the extension must
also be compiled for double-precision floats. See
:ref:`doc_large_world_coordinates` for details.