godot-headers

`GDNative / NativeScript`

GDNative enables the use of dynamically linked libraries inside of Godot.

NativeScript uses GDNative to implement scripts backed by native code.

Getting Started
FAQ

Getting Started

Build latest version of Godot	GitHub	Docs

Clone godot-headers into Library

Clone godot-headers under SimpleLibrary/

cd SimpleLibrary
git clone https://github.com/godotengine/godot-headers

Note that the master branch of this repository contains the header for the latest Godot master. If you want to build GDNative modules for older versions of Godot add -b <version> to the git clone command above. i.e. git clone https://github.com/godotengine/godot-headers -b 3.0 will retrieve headers compatible with Godot 3.0.

With the exception of a breaking change in the ARVR module between 3.0 and 3.1, GDNative plugins written for an older version of Godot will work in newer versions.

[SimpleLibrary]
  ├── lib/
  └── src/

Create Script

Create test.c under SimpleLibrary/src/

#include <gdnative/gdnative.h>
#include <nativescript/godot_nativescript.h>

#include <stdio.h>

void *test_constructor(godot_object *obj, void *method_data) {
        printf("test.constructor()\n");
        return 0;
}

void test_destructor(godot_object *obj, void *method_data, void *user_data) {
        printf("test.destructor()\n");
}

/** func _ready() **/
godot_variant test_ready(godot_object *obj, void *method_data, void *user_data, int num_args, godot_variant **args) {
        godot_variant ret;
        godot_variant_new_nil(&ret);

        printf("_ready()\n");

        return ret;
}

/** Library entry point **/
void GDN_EXPORT godot_gdnative_init(godot_gdnative_init_options *o) {
}

/** Library de-initialization **/
void GDN_EXPORT godot_gdnative_terminate(godot_gdnative_terminate_options *o) {
}

/** Script entry (Registering all the classes and stuff) **/
void GDN_EXPORT godot_nativescript_init(void *desc) {
	printf("nativescript init\n");

	godot_instance_create_func create_func = {
		.create_func = &test_constructor,
                .method_data = 0,
                .free_func   = 0
        };

        godot_instance_destroy_func destroy_func = {
                .destroy_func = &test_destructor,
                .method_data  = 0,
                .free_func    = 0
        };

        godot_nativescript_register_class(desc, "SimpleClass", "Node", create_func, destroy_func);

        {
                godot_instance_method method = {
                        .method = &test_ready,
                        .method_data = 0,
                        .free_func = 0
                };

                godot_method_attributes attr = {
                        .rpc_type = GODOT_METHOD_RPC_MODE_DISABLED
                };

                godot_nativescript_register_method(desc, "SimpleClass", "_ready", attr, method);
        }
}

godot_variant GDN_EXPORT some_test_procedure(void *data, godot_array *args) {
        godot_variant ret;
        godot_variant_new_int(&ret, 42);

        godot_string s;
        godot_string_new_with_wide_string(&s, L"Hello World", 11);
        godot_print(&s);

        godot_string_destroy(&s);

        return ret;
}

Expand details for example code.

Compile Library

On Linux:

clang -g -fPIC -std=c99 -c src/test.c -I/path/to/godot/headers/ -o src/test.os
clang -g -shared src/test.os -o lib/test.so

On MacOS:

clang -g -fPIC -std=c99 -c src/test.c -I/path/to/godot/headers/ -o src/test.os
clang -g -shared -framework Cocoa -Wl,-undefined,dynamic_lookup src/test.os -o lib/test.dylib

-g is for debugging information.
Use godot_nativescript_* methods only in the nativescript_init() function.

Create GDNativeLibrary Resource

The GDNativeLibrary resource contains links to the libraries for each platform.

Create a new resource in memory and edit it.
Select Resource > GDNativeLibrary.
Set the library file for your platform inside the inspector.
Save the edited resource as a .tres

Note: Remember to save GDNativeLibrary as .gdnlib

Expand details for screenshots.

Using GDNativeLibrary in GDScript

extends Node

func _ready():
        var gdn = GDNative.new()
        gdn.library = load("res://lib/libtest.tres")

        gdn.initialize()

        var res = gdn.call_native("standard_varcall", "some_test_procedure", [])

        print("result: ", res)

        gdn.terminate()

Attaching GDNativeLibrary to a Node

Attach a new script to a node.
In the pop-up dialog, choose NativeScript in the Language menu.
Enable built-in script, or create a .gdn file, which only contains a name.
Specify the Class Name.
Press Create.

The GDNativeLibrary field in a NativeScript is empty by default.

Expand details for screenshots.

FAQ

What is the difference between GDNative and NativeScript?

GDNative is a new class that can call native functions in libraries. GDScript / VisualScript / C#, etc, are able to use this class.

Godot treats NativeScript as a scripting language, enabling the use of GDNative to implement scripts backed by native code.

Which languages are binding as a NativeScript?

C++, D, Nim

Can you debug NativeScripts?

You must compile the library with debug symbols, and then you can use your debugger as usual.

Can you use one GDNativeLibrary for all NativeScripts?

You can! ✨

What is the reason behind the name "GDNative"?

GDNative was originally named "cscript" because it exposes a C API, but people mistook a relation to C#, which is sometimes abbreviated as "cs". Then named "DLScript", but that brought up some confusion, so we settled with GDNative. 📖

andrewpratt64/godot-headers