Rewrote c++20 module support

Author: texus

CMakeLists.txt

@@ -81,7 +81,8 @@ else() # Use c++14 by default on all other compilers
     set(TGUI_DEFAULT_CXX_STANDARD "14")
 endif()
 
-tgui_set_option(TGUI_CXX_STANDARD ${TGUI_DEFAULT_CXX_STANDARD} STRING "C++ standard version to build TGUI with. Possible values: 14, 17, 20 or 23. Projects using TGUI must use a c++ version equal or higher to this")
+set(TGUI_CXX_STANDARD_docstring "C++ standard version to build TGUI with. Possible values: 14, 17, 20 or 23. Projects using TGUI must use a c++ version equal or higher to this")
+tgui_set_option(TGUI_CXX_STANDARD ${TGUI_DEFAULT_CXX_STANDARD} STRING ${TGUI_CXX_STANDARD_docstring})
 
 # At least c++14 has to be used
 if(TGUI_CXX_STANDARD LESS "14")
@@ -160,14 +161,20 @@ string(TOUPPER "${TGUI_BACKEND}" TGUI_BACKEND_UPPERCASE)
 if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.28)
     # We currently don't create the option as it is still too experimental,
     # it can still be used if the user manually specifies the option though.
-    #option(TGUI_BUILD_AS_CXX_MODULE "ON to build TGUI as a c++20 module instead of using header files" OFF)
-    #mark_as_advanced(TGUI_BUILD_AS_CXX_MODULE)
-    if(TGUI_BUILD_AS_CXX_MODULE)
+    if (DEFINED TGUI_BUILD_AS_CXX_MODULE)
+        message(WARNING "Warning: TGUI_BUILD_AS_CXX_MODULE was renamed to TGUI_BUILD_CXX20_MODULE")
+        option(TGUI_BUILD_CXX20_MODULE "ON to build TGUI as a c++20 module that can be used as alternative to using header files" ${TGUI_BUILD_AS_CXX_MODULE})
+    else()
+        option(TGUI_BUILD_CXX20_MODULE "ON to build TGUI as a c++20 module that can be used as alternative to using header files" OFF)
+    endif()
+    mark_as_advanced(TGUI_BUILD_CXX20_MODULE)
+    if(TGUI_BUILD_CXX20_MODULE)
         if(TGUI_CXX_STANDARD LESS 20)
-            message(FATAL_ERROR "TGUI_BUILD_AS_CXX_MODULE can only be turned on if TGUI_CXX_STANDARD is set to at least 20")
+            message(WARNING "Warning: TGUI_CXX_STANDARD has been changed because the value was too low to use TGUI_BUILD_CXX20_MODULE")
+            set(TGUI_CXX_STANDARD 20 CACHE STRING ${TGUI_CXX_STANDARD_docstring} FORCE)
         endif()
         if(TGUI_OS_WINDOWS AND TGUI_SHARED_LIBS)
-            message(FATAL_ERROR "On Windows, BUILD_SHARED_LIBS must be OFF if TGUI_BUILD_AS_CXX_MODULE is ON")
+            message(FATAL_ERROR "On Windows, BUILD_SHARED_LIBS must be OFF if TGUI_BUILD_CXX20_MODULE is ON")
         endif()
     endif()
 endif()
@@ -353,10 +360,6 @@ endif()
 if(NOT TGUI_OS_ANDROID)
     option(TGUI_BUILD_EXAMPLES "TRUE to build the TGUI examples, FALSE to ignore them" FALSE)
     if(TGUI_BUILD_EXAMPLES)
-        if(TGUI_BUILD_AS_CXX_MODULE)
-            message(FATAL_ERROR "Examples don't support c++20 modules. Turn off either TGUI_BUILD_AS_CXX_MODULE or TGUI_BUILD_EXAMPLES.")
-        endif()
-
         add_subdirectory(examples)
     endif()
 endif()

cmake/Macros.cmake

@@ -85,7 +85,7 @@ function(tgui_set_global_compile_flags target)
         endif()
     endif()
 
-    if (NOT TGUI_BUILD_AS_CXX_MODULE)
+    if (NOT TGUI_BUILD_CXX20_MODULE)
         # We turn GNU extensions off to make sure that our code doesn't rely on them.
         # This isn't done when building TGUI as a module though. At least when using Clang 18, doing so required that the set_target_properties
         # function is also called on the user's target to avoid the "GNU extensions was enabled in PCH file but is currently disabled" error.
@@ -176,21 +176,3 @@ function(copy_dlls_to_exe post_build_destination install_destination target)
         endforeach()
     endif()
 endfunction()
-
-# Bundles a set of source files into a c++20 module
-function(tgui_create_module_from_sources source_file_list module_name)
-    file(READ "TGUI-Module.cppm.in" file_contents)
-    string(APPEND file_contents "\nexport module ${module_name};\n")
-    string(APPEND file_contents "\nexport import tgui;\n")
-    if(${ARGC} GREATER 2)
-        foreach(extra_module_to_export ${ARGN})
-            string(APPEND file_contents "export import ${extra_module_to_export};\n")
-        endforeach()
-    endif()
-    string(APPEND file_contents "\n")
-    foreach(source_file ${source_file_list})
-        string(APPEND file_contents "#include \"${CMAKE_CURRENT_SOURCE_DIR}/${source_file}\"\n")
-    endforeach()
-    file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/module_${module_name}.cppm" "${file_contents}")
-    set(module_source "${CMAKE_CURRENT_BINARY_DIR}/module_${module_name}.cppm" PARENT_SCOPE)
-endfunction()

doc/doxyfile.in

@@ -70,7 +70,7 @@ MACRO_EXPANSION        = YES
 EXPAND_ONLY_PREDEF     = YES
 PREDEFINED             = TGUI_DEPRECATED(x)= \
                          TGUI_COMPILED_WITH_CPP_VER=23 \
-                         TGUI_BUILD_AS_CXX_MODULE=0 \
+                         TGUI_BUILD_CXX20_MODULE=0 \
                          TGUI_HAS_WINDOW_BACKEND_SFML=1 \
                          TGUI_HAS_WINDOW_BACKEND_SDL=1 \
                          TGUI_HAS_WINDOW_BACKEND_GLFW=1 \

examples/CMakeLists.txt

@@ -45,6 +45,13 @@ macro(tgui_add_example target)
     target_link_libraries(${target} PRIVATE tgui tgui-gui-app-interface)
     tgui_set_global_compile_flags(${target})
     tgui_set_stdlib(${target})
+
+    if (TGUI_BUILD_CXX20_MODULE)
+        target_compile_definitions(${target} PRIVATE TGUI_BUILD_CXX20_MODULE)
+    endif()
+    if (DEFINED TGUI_USE_SDL3)
+        target_compile_definitions(${target} PRIVATE TGUI_USE_SDL3)
+    endif()
 endmacro()
 
 # Build the examples

examples/main-GLFW_GLES2.cpp

@@ -22,16 +22,21 @@
 //
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-#include <TGUI/TGUI.hpp>
-#include <TGUI/Backend/GLFW-GLES2.hpp>
-
-// Optional: include OpenGL ES functions via TGUI (which you can call AFTER creating the Gui object)
-// This will include a built-in GLAD header that defines all functions that exist in GLES 3.2 (and OpenGL 4.6)
-//#include <TGUI/Backend/Renderer/OpenGL.hpp>
-
 #define GLFW_INCLUDE_NONE // Don't let GLFW include an OpenGL extention loader
 #include <GLFW/glfw3.h>
 
+#if TGUI_BUILD_CXX20_MODULE
+    import tgui;
+    import tgui.backend.glfw_gles2;
+#else
+    #include <TGUI/TGUI.hpp>
+    #include <TGUI/Backend/GLFW-GLES2.hpp>
+
+    // Optional: include OpenGL ES functions via TGUI (which you can call AFTER creating the Gui object)
+    // This will include a built-in GLAD header that defines all functions that exist in GLES 3.2 (and OpenGL 4.6)
+    //#include <TGUI/Backend/Renderer/OpenGL.hpp>
+#endif
+
 bool runExample(tgui::BackendGui& gui);
 
 // We don't put this code in main() to make sure that all TGUI resources are destroyed before destroying GLFW

examples/main-GLFW_OPENGL3.cpp

@@ -22,16 +22,21 @@
 //
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-#include <TGUI/TGUI.hpp>
-#include <TGUI/Backend/GLFW-OpenGL3.hpp>
-
-// Optional: include (modern) OpenGL functions via TGUI (which you can call AFTER creating the Gui object)
-// This will include a built-in GLAD header that defines all functions that exist in OpenGL 4.6 (and GLES 3.2)
-//#include <TGUI/Backend/Renderer/OpenGL.hpp>
-
 #define GLFW_INCLUDE_NONE // Don't let GLFW include an OpenGL extention loader
 #include <GLFW/glfw3.h>
 
+#if TGUI_BUILD_CXX20_MODULE
+    import tgui;
+    import tgui.backend.glfw_opengl3;
+#else
+    #include <TGUI/TGUI.hpp>
+    #include <TGUI/Backend/GLFW-OpenGL3.hpp>
+
+    // Optional: include (modern) OpenGL functions via TGUI (which you can call AFTER creating the Gui object)
+    // This will include a built-in GLAD header that defines all functions that exist in OpenGL 4.6 (and GLES 3.2)
+    //#include <TGUI/Backend/Renderer/OpenGL.hpp>
+#endif
+
 bool runExample(tgui::BackendGui& gui);
 
 // We don't put this code in main() to make sure that all TGUI resources are destroyed before destroying GLFW

examples/main-RAYLIB.cpp

@@ -22,8 +22,14 @@
 //
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-#include <TGUI/TGUI.hpp>
-#include <TGUI/Backend/raylib.hpp>
+#if TGUI_BUILD_CXX20_MODULE
+    #include <raylib.h>
+    import tgui;
+    import tgui.backend.raylib;
+#else
+    #include <TGUI/TGUI.hpp>
+    #include <TGUI/Backend/raylib.hpp>
+#endif
 
 bool runExample(tgui::BackendGui& gui);
 

examples/main-SDL_GLES2.cpp

@@ -22,14 +22,25 @@
 //
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-#include <TGUI/TGUI.hpp>
-#include <TGUI/Backend/SDL-GLES2.hpp>
-
-#if SDL_MAJOR_VERSION >= 3
-    #include <SDL3/SDL_main.h>
-    #include <SDL3/SDL_opengles2.h>
+#if TGUI_BUILD_CXX20_MODULE
+    #include <TGUI/extlibs/IncludeSDL.hpp>
+    #if SDL_MAJOR_VERSION >= 3
+        #include <SDL3/SDL_main.h>
+        #include <SDL3/SDL_opengles2.h>
+    #else
+        #include <SDL_opengles2.h>
+    #endif
+    import tgui;
+    import tgui.backend.sdl_gles2;
 #else
-    #include <SDL_opengles2.h>
+    #include <TGUI/TGUI.hpp>
+    #include <TGUI/Backend/SDL-GLES2.hpp>
+    #if TGUI_USE_SDL3
+        #include <SDL3/SDL_main.h>
+        #include <SDL3/SDL_opengles2.h>
+    #else
+        #include <SDL_opengles2.h>
+    #endif
 #endif
 
 bool runExample(tgui::BackendGui& gui);
@@ -69,7 +80,11 @@ int main(int, char **)
     run_application(window);
 
     // Note that all TGUI resources must be destroyed before SDL is cleaned up
+#if SDL_MAJOR_VERSION >= 3
+    SDL_GL_DestroyContext(glContext);
+#else
     SDL_GL_DeleteContext(glContext);
+#endif
     SDL_DestroyWindow(window);
     SDL_Quit();
     return 0;

examples/main-SDL_GPU.cpp

@@ -22,10 +22,22 @@
 //
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-#include <TGUI/TGUI.hpp>
-#include <TGUI/Backend/SDL-GPU.hpp>
 #include <SDL3/SDL_main.h>
 
+#if TGUI_BUILD_CXX20_MODULE
+    #include <TGUI/extlibs/IncludeSDL.hpp>
+    #if SDL_MAJOR_VERSION >= 3
+        #include <SDL3_ttf/SDL_ttf.h>
+    #else
+        #include <SDL_ttf.h>
+    #endif
+    import tgui;
+    import tgui.backend.sdl_gpu;
+#else
+    #include <TGUI/TGUI.hpp>
+    #include <TGUI/Backend/SDL-GPU.hpp>
+#endif
+
 bool runExample(tgui::BackendGui& gui);
 
 // We don't put this code in main() to make sure that all TGUI resources are destroyed before destroying SDL

examples/main-SDL_OPENGL3.cpp

@@ -22,14 +22,25 @@
 //
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-#include <TGUI/TGUI.hpp>
-#include <TGUI/Backend/SDL-OpenGL3.hpp>
-
-#if SDL_MAJOR_VERSION >= 3
-    #include <SDL3/SDL_main.h>
-    #include <SDL3/SDL_opengl.h>
+#if TGUI_BUILD_CXX20_MODULE
+    #include <TGUI/extlibs/IncludeSDL.hpp>
+    #if SDL_MAJOR_VERSION >= 3
+        #include <SDL3/SDL_main.h>
+        #include <SDL3/SDL_opengl.h>
+    #else
+        #include <SDL_opengl.h>
+    #endif
+    import tgui;
+    import tgui.backend.sdl_opengl3;
 #else
-    #include <SDL_opengl.h>
+    #include <TGUI/TGUI.hpp>
+    #include <TGUI/Backend/SDL-OpenGL3.hpp>
+    #if TGUI_USE_SDL3
+        #include <SDL3/SDL_main.h>
+        #include <SDL3/SDL_opengl.h>
+    #else
+        #include <SDL_opengl.h>
+    #endif
 #endif
 
 bool runExample(tgui::BackendGui& gui);
@@ -69,7 +80,11 @@ int main(int, char **)
     run_application(window);
 
     // Note that all TGUI resources must be destroyed before SDL is cleaned up
+#if SDL_MAJOR_VERSION >= 3
+    SDL_GL_DestroyContext(glContext);
+#else
     SDL_GL_DeleteContext(glContext);
+#endif
     SDL_DestroyWindow(window);
     SDL_Quit();
     return 0;