b4632e317d
Proper initialization for godot-cpp classes with memnew. Extension classes (i.e. the `GDCLASS` macro) behave differently from regular wrapped classes, and requires Godot to initialize them during object construction. This commit update the GDCLASS macro to not create/destroy the instance during the bindings callback, but during the extension callbacks. When setting the object instance, the bindings instance is set to the pointer of the extension instance so that it can later be retrieved normally via `object_get_instance_bindings`.
godot-cpp
C++ bindings for the Godot extension API.
Note: this is a work in progress for the extension system included in Godot 4.0
Stub
Both this whole bindings system and this document are still work in progress and thus it is still incomplete. It will be improved once the extension API is settled.
How to use
It's a bit similar to what it was for 3.x but also a bit different.
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 .gdnlibbefore. Follow the example:
[configuration]
entry_symbol = "example_library_init"
[libraries]
Linux.64 = "bin/x11/libgdexample.so"
The entry_symbol is the name of the function that initializes your library. It should be similar to following layout:
extern "C" {
GDNativeBool GDN_EXPORT example_library_init(const GDNativeInterface *p_interface, const GDNativeExtensionClassLibraryPtr p_library, GDNativeInitialization *r_initialization) {
GDNativeBool result = godot::GDExtensionBinding::init(p_interface, p_library, r_initialization);
if (result) {
register_example_types();
}
return result;
}
}
The register_example_types() should register the classes in ClassDB, very like a Godot module would do.
using namespace godot;
void register_example_types() {
ClassDB::register_class<Example>();
}
Extension registering has not yet been added to the Godot editor, so to make it recognize your extension you need to add the following section to your project.godot:
[native_extensions]
paths=["res://example.gdextension"]
Any node and resource you register will be available in the corresponding Create... dialog. Any class will be available to scripting as well.
Example
Check the project in the test folder for an example on how to use and register different things.
This project isn't yet made to run in CI.
Issues
This really needs to be tested and very likely has things missing that weren't noticed yet. Use at your own risk (and contribute back with reports and fixes if you can).