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Split C++ (godot-cpp) and GDExtension system info into separate categ…
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Ivorforce committed Feb 7, 2025
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2 changes: 1 addition & 1 deletion tutorials/scripting/gdextension/gdextension_c_example.rst
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Expand Up @@ -2162,5 +2162,5 @@ quite straightforward and not very verbose.

If you want to create actual extensions, it is preferred to use the C++ bindings
instead, as it takes away all of the boilerplate from your code. Check the
:ref:`GDExtension C++ example <doc_gdextension_cpp_example>` to see how you can
:ref:`GDExtension C++ example <doc_godot_cpp_getting_started>` to see how you can
do this.
2 changes: 1 addition & 1 deletion tutorials/scripting/gdextension/gdextension_file.rst
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Expand Up @@ -9,7 +9,7 @@ Introduction
The ``.gdextension`` file in your project contains the instructions for how to load
the GDExtension. The instructions are separated into specific sections. This page
should give you a quick overview of the different options available to you. For an introduction
how to get started with GDExtensions take a look at the :ref:`GDExtension C++ Example <doc_gdextension_cpp_example>`.
how to get started with the C++ (godot-cpp), take a look at the :ref:`GDExtension C++ Example <doc_godot_cpp_getting_started>`.

Configuration section
---------------------
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24 changes: 18 additions & 6 deletions tutorials/scripting/gdextension/index.rst
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:allow_comments: False

GDExtension
===========
.. _doc_gdextension:

The GDExtension system
======================

**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 runtime. 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>`.

This section describes how GDExtension works, and is generally aimed at people wanting to make a GDExtension from
scratch, for example to create language bindings. If you want to use existing language bindings, please refer to other
articles instead, such as the articles about :ref:`C++ (godot-cpp) <doc_godot_cpp>` or one of the
:ref:`community-made ones <doc_what_is_gdnative_third_party_bindings>`.

.. toctree::
:maxdepth: 1
:name: toc-tutorials-gdnative
:name: toc-tutorials-gdextension

what_is_gdextension
gdextension_cpp_example
gdextension_c_example
gdextension_file
gdextension_docs_system
gdextension_c_example
127 changes: 1 addition & 126 deletions tutorials/scripting/gdextension/what_is_gdextension.rst
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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 runtime. 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::

GDExtension is currently *experimental*, which means that we may
break compatibility in order to fix major bugs or include critical features.

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 runtime.
- 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>`__
- `Go <https://github.com/grow-graphics/gd>`__
- `Nim <https://github.com/godot-nim/gdext-nim>`__
- `Rust <https://github.com/godot-rust/gdext>`__
- `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.

.. _doc_what_is_gdextension_version_compatibility:

Version compatibility
---------------------

Usually, 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.

For this reason, when creating GDExtensions, you may want to target the lowest version of
Godot that has the features you need, *not* the most recent version of Godot. This can
save you from needing to create multiple builds for different versions of Godot.

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`).

GDExtensions are also only compatible with engine builds that use the same
level of floating-point precision the extension was compiled for. This means
that if you use an engine build with double-precision floats, the extension must
also be compiled for double-precision floats and use an ``extension_api.json``
file generated by your custom engine build. See :ref:`doc_large_world_coordinates`
for details.

Generally speaking, if you build a custom version of Godot, you should generate an
``extension_api.json`` from it for your GDExtensions, because it may have some differences
from official Godot builds.
Placeholder.
96 changes: 96 additions & 0 deletions tutorials/scripting/godot_cpp/about_godot_cpp.rst
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.. _doc_about_godot_cpp:

About godot-cpp
===============

`godot-cpp <https://github.com/godotengine/godot-cpp>`__ are the official C++ GDExtension bindings, maintained
as part of the Godot project.

godot-cpp is built with the :ref:`GDExtension system <doc_gdextension>`, which allows access to Godot in almost the
same way as :ref:`modules <doc_custom_modules_in_cpp>`: A lot of `engine code <https://github.com/godotengine/godot>`__
can be used in your godot-cpp project almost verbatim.

In particular, godot-cpp has access to all functions that :ref:`GDScript <doc_gdscript>` and :ref:`C# <doc_c_sharp>`
have, and additional access to a few more which are provided for fast low-level access of data.

Differences between godot-cpp and C++ modules
-----------------------------------------------

You can use both `godot-cpp <https://github.com/godotengine/godot-cpp>`__
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::

godot-cpp is currently *experimental*, which means that we may
break compatibility in order to fix major bugs or include critical features.


Advantages of godot-cpp
~~~~~~~~~~~~~~~~~~~~~~~

Unlike modules, godot-cpp (and GDExtension systems in general) don'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:

- You can use the same compiled godot-cpp 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 runtime.
- godot-cpp 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 godot-cpp.

Advantages of C++ modules
~~~~~~~~~~~~~~~~~~~~~~~~~

We recommend :ref:`C++ modules <doc_custom_modules_in_cpp>` in cases where
godot-cpp (or another GDExtension system) 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.

.. _doc_what_is_gdextension_version_compatibility:

Version compatibility
---------------------

Usually, 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.

For this reason, when creating GDExtensions, you may want to target the lowest version of
Godot that has the features you need, *not* the most recent version of Godot. This can
save you from needing to create multiple builds for different versions of Godot.

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`).

GDExtensions are also only compatible with engine builds that use the same
level of floating-point precision the extension was compiled for. This means
that if you use an engine build with double-precision floats, the extension must
also be compiled for double-precision floats and use an ``extension_api.json``
file generated by your custom engine build. See :ref:`doc_large_world_coordinates`
for details.

Generally speaking, if you build a custom version of Godot, you should generate an
``extension_api.json`` from it for your GDExtensions, because it may have some differences
from official Godot builds.
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.. _doc_gdextension_docs_system:
.. _doc_godot_cpp_docs_system:

GDExtension documentation system
================================
Expand All @@ -15,7 +15,7 @@ XML files (one per class) to document the exposed constructors, properties, meth

.. note::

We are assuming you are using the project files explained in the :ref:`GDExtension C++ Example <doc_gdextension_cpp_example>`
We are assuming you are using the project files explained in the :ref:`GDExtension C++ Example <doc_godot_cpp_getting_started>`
with the following structure:

.. code-block:: none
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