Fallback to OpenGL 3 if Vulkan isn't available on Wayland

Author: MonterraByte

platform/linuxbsd/wayland/display_server_wayland.cpp

@@ -1344,20 +1344,28 @@ DisplayServerWayland::DisplayServerWayland(const String &p_rendering_driver, Win
 		if (rendering_context->initialize() != OK) {
 			memdelete(rendering_context);
 			rendering_context = nullptr;
-			r_error = ERR_CANT_CREATE;
+			bool fallback_to_opengl3 = GLOBAL_GET("rendering/rendering_device/fallback_to_opengl3");
+			if (fallback_to_opengl3 && rendering_driver != "opengl3") {
+				WARN_PRINT("Your video card drivers seem not to support the required Vulkan version, switching to OpenGL 3.");
+				rendering_driver = "opengl3";
+				OS::get_singleton()->set_current_rendering_method("gl_compatibility");
+				OS::get_singleton()->set_current_rendering_driver_name(rendering_driver);
+			} else {
+				r_error = ERR_CANT_CREATE;
 
-			if (p_rendering_driver == "vulkan") {
-				OS::get_singleton()->alert(
-						vformat("Your video card drivers seem not to support the required Vulkan version.\n\n"
-								"If possible, consider updating your video card drivers or using the OpenGL 3 driver.\n\n"
-								"You can enable the OpenGL 3 driver by starting the engine from the\n"
-								"command line with the command:\n\n    \"%s\" --rendering-driver opengl3\n\n"
-								"If you recently updated your video card drivers, try rebooting.",
-								executable_name),
-						"Unable to initialize Vulkan video driver");
-			}
+				if (p_rendering_driver == "vulkan") {
+					OS::get_singleton()->alert(
+							vformat("Your video card drivers seem not to support the required Vulkan version.\n\n"
+									"If possible, consider updating your video card drivers or using the OpenGL 3 driver.\n\n"
+									"You can enable the OpenGL 3 driver by starting the engine from the\n"
+									"command line with the command:\n\n    \"%s\" --rendering-driver opengl3\n\n"
+									"If you recently updated your video card drivers, try rebooting.",
+									executable_name),
+							"Unable to initialize Vulkan video driver");
+				}
 
-			ERR_FAIL_MSG(vformat("Could not initialize %s", rendering_driver));
+				ERR_FAIL_MSG(vformat("Could not initialize %s", rendering_driver));
+			}
 		}
 
 		driver_found = true;