Add Windows support.

Author: korompg

README.md

@@ -35,9 +35,12 @@ git clone --recursive https://github.com/migeran/libgodot_project
 
 cd libgodot_project
 
-# Build for the host platform (Mac and Linux)
+# Build for Mac and Linux
 ./build_libgodot.sh
 
+# Or build for Windows
+build_libgodot.bat
+
 # Build for iOS (Mac only)
 ./build_libgodot.sh --target ios 
 ```
@@ -48,6 +51,7 @@ The C++ sample shows how Godot can be controlled by a host process, by displayin
 
 After libgodot is compiled successfully, run the following commands to test the C++ sample:
 
+On Linux and MacOS:
 ```
 cd samples/cpp_sample
 mkdir build
@@ -56,6 +60,16 @@ cd build
 ./sample
 ```
 
+On Windows:
+```
+cd samples/cpp_sample
+mkdir build
+cmake -S . -B build -G Ninja
+cd build
+ninja
+sample.exe
+```
+
 ### SwiftUI Sample
 
 To test the SwiftUI sample, just open the ios_sample project in XCode 15.1+, build it and run on any iOS device. (iOS Simulator is not supported due to Godot limitations.)
@@ -96,7 +110,7 @@ This class is made accessible over the GDExtension API. This class can be used t
 To actually create a Godot instance a new symbol is added to the GDExtension API:
 
 ```cpp
-GDExtensionObjectPtr gdextension_create_godot_instance(int p_argc, char *p_argv[], GDExtensionInitializationFunction p_init_func);
+GDExtensionObjectPtr libgodot_create_godot_instance(int p_argc, char *p_argv[], GDExtensionInitializationFunction p_init_func, void *p_platform_data);
 ```
 
 This function can be used to create a new Godot instance and return a GodotInstance object reference to control it. Both samples show how easy it is to bind this function and then use the generated GDExtension API bindings with the returned GodotInstance object.

build_libgodot.bat

@@ -0,0 +1,18 @@
+set BASE_DIR=%~dp0
+
+cd %BASE_DIR%
+mkdir build
+
+cd godot
+
+call scons platform=windows arch=x86_64 verbose=yes msvc=yes dev_build=yes debug_symbols=yes
+call scons platform=windows target=template_debug arch=x86_64 verbose=yes msvc=yes library_type=shared_library dev_build=yes debug_symbols=yes
+
+copy /y bin\godot.windows.template_debug.dev.x86_64.dll ..\build\libgodot.dll
+
+start /wait bin\godot.windows.editor.dev.x86_64.exe --dump-extension-api
+copy /y extension_api.json ..\build\extension_api.json
+copy /y ..\build\extension_api.json ..\godot-cpp\gdextension
+copy /y core\extension\gdextension_interface.h ..\godot-cpp\gdextension
+
+cd ..

godot

@@ -22,7 +22,11 @@ target_include_directories(${PROJECT_NAME} SYSTEM
 		${GODOT_CPP_DIR}/gen/include
 		${GODOT_CPP_DIR}/gdextension
 )
-target_link_libraries(${PROJECT_NAME} dl godot-cpp Threads::Threads)
+if (WIN32)
+    target_link_libraries(${PROJECT_NAME} godot-cpp Threads::Threads)
+else()
+    target_link_libraries(${PROJECT_NAME} dl godot-cpp Threads::Threads)
+endif (WIN32)
 add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
                    COMMAND ${CMAKE_COMMAND} -E copy
                        ${LIBGODOT_BUILD_DIR}/libgodot${CMAKE_SHARED_LIBRARY_SUFFIX}

godot-cpp

@@ -1,6 +1,10 @@
 #include <stdlib.h>
 #include <stdio.h>
+#if defined(__APPLE__) || defined(__unix__)
 #include <dlfcn.h>
+#elif defined(_WIN32)
+#include <windows.h>
+#endif
 #include <string>
 #include <vector>
 
@@ -13,8 +17,10 @@
 
 #ifdef __APPLE__
 #define LIBGODOT_LIBRARY_NAME "libgodot.dylib"
-#else
+#elif defined(__unix__)
 #define LIBGODOT_LIBRARY_NAME "./libgodot.so"
+#elif defined(_WIN32)
+#define LIBGODOT_LIBRARY_NAME "libgodot.dll"
 #endif
 
 extern "C" {
@@ -47,6 +53,7 @@ GDExtensionBool GDE_EXPORT gdextension_default_init(GDExtensionInterfaceGetProcA
 class LibGodot {
 public:
     LibGodot(std::string p_path = LIBGODOT_LIBRARY_NAME) {
+#if defined(__APPLE__) || defined(__unix__)
         handle = dlopen(p_path.c_str(), RTLD_LAZY);
         if (handle == nullptr) {
             fprintf(stderr, "Error opening libgodot: %s\n", dlerror());
@@ -66,23 +73,49 @@ class LibGodot {
             handle == nullptr;
             return;
         }
+#elif defined(_WIN32)
+        LPCSTR libgodot_library_name = reinterpret_cast<LPCSTR>(LIBGODOT_LIBRARY_NAME);
+        handle = LoadLibrary(libgodot_library_name);
+        if (handle == NULL) {
+            fprintf(stderr, "Error opening libgodot: %lu\n", GetLastError());
+            return;
+        }
+        func_libgodot_create_godot_instance = (GDExtensionObjectPtr (*)(int, char *[], GDExtensionInitializationFunction, void *))GetProcAddress(handle, "libgodot_create_godot_instance");
+        if (func_libgodot_create_godot_instance == NULL) {
+            fprintf(stderr, "Error acquiring function: %lu\n", GetLastError());
+            FreeLibrary(handle);
+            return;
+        }
+#endif
     }
 
     ~LibGodot() {
         if (is_open()) {
+#if defined(__APPLE__) || defined(__unix__)
             dlclose(handle);
+#elif defined(_WIN32)
+            FreeLibrary(handle);
+#endif
         }
     }
 
     bool is_open() {
+#if defined(__APPLE__) || defined(__unix__)
         return handle != nullptr && func_libgodot_create_godot_instance != nullptr;
+#elif defined(_WIN32)
+        return handle != NULL && func_libgodot_create_godot_instance != NULL;
+#endif
     }
 
     godot::GodotInstance *create_godot_instance(int p_argc, char *p_argv[], GDExtensionInitializationFunction p_init_func = gdextension_default_init) {
         if (!is_open()) {
             return nullptr;
         }
-        GDExtensionObjectPtr instance = func_libgodot_create_godot_instance(p_argc, p_argv, p_init_func);
+#if defined(__APPLE__) || defined(__unix__)
+        GDExtensionObjectPtr instance = func_libgodot_create_godot_instance(p_argc, p_argv, p_init_func, nullptr);
+#elif defined(_WIN32)
+        GDExtensionObjectPtr instance = func_libgodot_create_godot_instance(p_argc, p_argv, p_init_func, handle);
+#endif
         if (instance == nullptr) {
             return nullptr;
         }
@@ -95,9 +128,15 @@ class LibGodot {
     }
 
 private:
+#if defined(__APPLE__) || defined(__unix__)
     void *handle = nullptr;
-    GDExtensionObjectPtr (*func_libgodot_create_godot_instance)(int, char *[], GDExtensionInitializationFunction) = nullptr;
+    GDExtensionObjectPtr (*func_libgodot_create_godot_instance)(int, char *[], GDExtensionInitializationFunction, void *) = nullptr;
     void (*func_libgodot_destroy_godot_instance)(GDExtensionObjectPtr) = nullptr;
+#elif defined(_WIN32)
+    HINSTANCE handle = NULL;
+    GDExtensionObjectPtr (*func_libgodot_create_godot_instance)(int, char *[], GDExtensionInitializationFunction, void *) = NULL;
+    void (*func_libgodot_destroy_godot_instance)(GDExtensionObjectPtr) = NULL;
+#endif
 };
 
 int main(int argc, char **argv) {