Now try Metal, Vulkan and then finally Dummy in that order

This only applies to the SDL backend though, this will be expanded
upon though.

platforms/sdl/main.cpp.in

@@ -16,6 +16,8 @@
 #include "gfx_metal.hpp"
 #endif
 
+#include "gfx_dummy.hpp"
+
 #ifdef PLATFORM_WINDOWS
 #include <winrt/Windows.UI.ViewManagement.h>
 #pragma comment(lib, "windowsapp")
@@ -391,17 +393,33 @@ void* platform::get_next_image(window_ptr window) {
     return nullptr;
 }
 
+template<class GFXBackend>
+void try_initialize() {
+    if(gfx_interface == nullptr) {
+        auto backend = new GFXBackend();
+        const bool supported = backend->is_supported();
+        if(!supported) {
+            prism::log("Failed to initialize GFX backend... trying next...");
+        } else {
+            gfx_interface = backend;
+            platform::initialize_context(gfx_interface->required_context());
+        }
+    }
+}
+
 int main(int argc, char* argv[]) {
     SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER);
 
     // determine gfx context at the beginning
 #ifdef ENABLE_METAL
-    gfx_interface = new GFXMetal();
+    try_initialize<GFXMetal>();
-#else
-    gfx_interface = new GFXVulkan();
 #endif
 
-    platform::initialize_context(gfx_interface->required_context());
+#ifdef ENABLE_VULKAN
+    try_initialize<GFXVulkan>();
+#endif
+
+    try_initialize<GFXDummy>();
 
     engine = new prism::engine(argc, argv);