feat(vulkan): gfxrenderer picks the opengl 4.6 or the vulkan 1.4 renderer (B1-B3)

application/application.h

@@ -17,6 +17,8 @@ http://mozilla.org/MPL/2.0/.
 #include "utilities/uart.h"
 #endif
 
+struct gfx_backend_desc;
+
 class eu07_application {
     const int MAX_NETWORK_PER_FRAME = 1000;
 
@@ -105,8 +107,12 @@ private:
     int  init_settings( int Argc, char *Argv[] );
     int  init_locale();
     int  init_glfw();
+    // the backend of the renderer picked by gfxrenderer, opengl if it can't run here
+    void select_gfx_backend();
+    int  create_main_window();
+    // the backend picked can't run after all: the main window is made anew for opengl
+    int  fallback_to_opengl( std::string const &Reason );
     void init_callbacks();
-    int  init_ogl();
     int  init_ui();
     int  init_gfx();
     int  init_audio();
@@ -122,6 +128,7 @@ private:
     mode_stack m_modestack; // current behaviour mode
     python_taskqueue m_taskqueue;
     std::vector<GLFWwindow *> m_windows;
+    gfx_backend_desc const *m_gfxbackend { nullptr }; // owned by gfx_renderer_factory
 
 	std::optional<network::manager> m_network;
     std::optional<headtrack> m_headtrack;