Fix Cannot find compatible metal driver on macOS due to the newest Vulkan SDK regression

#1469

Source/Engine/GraphicsDevice/Vulkan/GPUDeviceVulkan.Layers.cpp

@@ -35,6 +35,10 @@ static const char* GValidationLayers[] =
 
 static const char* GInstanceExtensions[] =
 {
+#if PLATFORM_APPLE_FAMILY && defined(VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME)
+    VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME,
+    VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME,
+#endif
 #if VK_EXT_validation_cache
     VK_EXT_VALIDATION_CACHE_EXTENSION_NAME,
 #endif
@@ -46,6 +50,9 @@ static const char* GInstanceExtensions[] =
 
 static const char* GDeviceExtensions[] =
 {
+#if PLATFORM_APPLE_FAMILY && defined(VK_KHR_PORTABILITY_SUBSET_EXTENSION_NAME)
+    VK_KHR_PORTABILITY_SUBSET_EXTENSION_NAME,
+#endif
     VK_KHR_SWAPCHAIN_EXTENSION_NAME,
 #if VK_KHR_maintenance1
     VK_KHR_MAINTENANCE1_EXTENSION_NAME,

Source/Engine/GraphicsDevice/Vulkan/GPUDeviceVulkan.cpp

@@ -1078,6 +1078,9 @@ GPUDevice* GPUDeviceVulkan::Create()
 
     VkInstanceCreateInfo instInfo;
     RenderToolsVulkan::ZeroStruct(instInfo, VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO);
+#ifdef PLATFORM_APPLE_FAMILY
+    instInfo.flags |= VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR;
+#endif
     instInfo.pApplicationInfo = &appInfo;
 
     GetInstanceLayersAndExtensions(InstanceExtensions, InstanceLayers, SupportsDebugUtilsExt);

Source/Engine/GraphicsDevice/Vulkan/IncludeVulkanHeaders.h

@@ -41,4 +41,15 @@
 #define VMA_NOT_NULL
 #include <ThirdParty/VulkanMemoryAllocator/vk_mem_alloc.h>
 
+#if PLATFORM_APPLE_FAMILY
+// Declare potentially missing extensions from newer SDKs
+#ifndef VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME
+#define VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME "VK_KHR_portability_enumeration"
+#define VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR 0x00000001
+#endif
+#ifndef VK_KHR_PORTABILITY_SUBSET_EXTENSION_NAME
+#define VK_KHR_PORTABILITY_SUBSET_EXTENSION_NAME "VK_KHR_portability_subset"
+#endif
+#endif
+
 #endif