VulkanRenderer: implement metal view

The metal view backing the MoltenVK compatibility wrapper is written in
Obj-C.

It would have been possible to use the Objective-C runtime in C++ but
the code is less performant (the symbol binding is done at first use
instead of the beginning of the program) and actually harder to get
right.

Note that MoltenVK is not linked to the loader, so the libMoltenVK.dylib
object must be available for loading.

include/Nazara/VulkanRenderer/Wrapper/Instance.hpp

@@ -34,6 +34,10 @@
 #include <vulkan/vulkan_xcb.h>
 #endif
 
+#ifdef VK_USE_PLATFORM_METAL_EXT
+#include <vulkan/vulkan_metal.h>
+#endif
+
 #ifdef VK_USE_PLATFORM_XLIB_KHR
 typedef struct _XDisplay Display;
 typedef unsigned long XID;

include/Nazara/VulkanRenderer/Wrapper/InstanceFunctions.hpp

@@ -97,6 +97,12 @@ NAZARA_VULKANRENDERER_INSTANCE_EXT_BEGIN(VK_KHR_win32_surface)
 NAZARA_VULKANRENDERER_INSTANCE_EXT_END()
 #endif
 
+#ifdef VK_USE_PLATFORM_METAL_EXT
+NAZARA_VULKANRENDERER_INSTANCE_EXT_BEGIN(VK_EXT_metal_surface)
+	NAZARA_VULKANRENDERER_INSTANCE_FUNCTION(vkCreateMetalSurfaceEXT)
+NAZARA_VULKANRENDERER_INSTANCE_EXT_END()
+#endif
+
 #undef NAZARA_VULKANRENDERER_INSTANCE_CORE_EXT_FUNCTION
 #undef NAZARA_VULKANRENDERER_INSTANCE_EXT_BEGIN
 #undef NAZARA_VULKANRENDERER_INSTANCE_EXT_END

include/Nazara/VulkanRenderer/Wrapper/Surface.hpp

@@ -12,6 +12,11 @@
 #include <Nazara/VulkanRenderer/Wrapper/Instance.hpp>
 #include <Nazara/VulkanRenderer/Wrapper/Loader.hpp>
 
+#ifdef VK_USE_PLATFORM_METAL_EXT
+#include <objc/runtime.h>
+#include <vulkan/vulkan_metal.h>
+#endif
+
 namespace Nz 
 {
 	namespace Vk
@@ -54,6 +59,11 @@ namespace Nz
 				inline bool Create(HINSTANCE instance, HWND handle, VkWin32SurfaceCreateFlagsKHR flags = 0, const VkAllocationCallbacks* allocator = nullptr);
 				#endif
 
+				#ifdef VK_USE_PLATFORM_METAL_EXT
+				inline bool Create(const VkMetalSurfaceCreateInfoEXT& createInfo, const VkAllocationCallbacks* allocator = nullptr);
+				inline bool Create(id layer, const VkAllocationCallbacks* allocator = nullptr);
+				#endif
+
 				inline void Destroy();
 
 				bool GetCapabilities(VkPhysicalDevice physicalDevice, VkSurfaceCapabilitiesKHR* surfaceCapabilities) const;

include/Nazara/VulkanRenderer/Wrapper/Surface.inl

@@ -140,6 +140,27 @@ namespace Nz
 		}
 		#endif
 
+		#ifdef VK_USE_PLATFORM_METAL_EXT
+		inline bool Surface::Create(const VkMetalSurfaceCreateInfoEXT& createInfo, const VkAllocationCallbacks* allocator)
+		{
+			m_lastErrorCode = m_instance.vkCreateMetalSurfaceEXT(m_instance, &createInfo, allocator, &m_surface);
+			return Create(allocator);
+		}
+
+		inline bool Surface::Create(id layer, const VkAllocationCallbacks* allocator)
+		{
+			VkMetalSurfaceCreateInfoEXT createInfo =
+			{
+				VK_STRUCTURE_TYPE_METAL_SURFACE_CREATE_INFO_EXT,
+				nullptr,
+				0,
+				layer
+			};
+
+			return Create(createInfo, allocator);
+		}
+		#endif
+
 		inline void Surface::Destroy()
 		{
 			if (m_surface != VK_NULL_HANDLE)
@@ -262,6 +283,10 @@ namespace Nz
 				return true;
 #endif
 
+#ifdef VK_USE_PLATFORM_METAL_EXT
+			if (instance.IsExtensionLoaded(VK_EXT_METAL_SURFACE_EXTENSION_NAME))
+				return true;
+#endif
 			return false;
 		}
 

src/Nazara/VulkanRenderer/Vulkan.cpp

@@ -244,6 +244,10 @@ namespace Nz
 			enabledExtensions.push_back(VK_KHR_WIN32_SURFACE_EXTENSION_NAME);
 			#endif
 
+			#ifdef VK_USE_PLATFORM_METAL_EXT
+			enabledExtensions.push_back(VK_EXT_METAL_SURFACE_EXTENSION_NAME);
+			#endif
+
 			if (availableExtensions.count(VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME))
 				enabledExtensions.push_back(VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME);
 

src/Nazara/VulkanRenderer/VulkanSurface.cpp

@@ -7,8 +7,17 @@
 #include <vulkan/vk_sdk_platform.h>
 #include <Nazara/VulkanRenderer/Debug.hpp>
 
+#ifdef VK_USE_PLATFORM_METAL_EXT
+#include <objc/runtime.h>
+#include <vulkan/vulkan_metal.h>
+#endif
+
 namespace Nz
 {
+	#ifdef VK_USE_PLATFORM_METAL_EXT
+	id CreateAndAttachMetalLayer(void* window);
+	#endif
+
 	VulkanSurface::VulkanSurface() :
 	m_surface(Vulkan::GetInstance())
 	{
@@ -60,6 +69,11 @@ namespace Nz
 			}
 		}
 		#elif defined(NAZARA_PLATFORM_MACOS)
+		{
+			NazaraAssert(handle.type == WindowBackend::Cocoa, "expected cocoa window");
+			id layer = CreateAndAttachMetalLayer(handle.cocoa.window);
+			success = m_surface.Create(layer);
+		}
 		#else
 		#error This OS is not supported by Vulkan
 		#endif

src/Nazara/VulkanRenderer/VulkanSurfaceMetal.mm

@@ -0,0 +1,16 @@
+#import <AppKit/NSView.h>
+#import <AppKit/NSWindow.h>
+#import <QuartzCore/CAMetalLayer.h>
+
+namespace Nz
+{
+	id CreateAndAttachMetalLayer(void* window) {
+		NSWindow* obj = (__bridge NSWindow*)window;
+		NSView* view = [[NSView alloc] initWithFrame:obj.frame];
+		[view setLayer:[CAMetalLayer layer]];
+		[view setWantsLayer:YES];
+		view.autoresizingMask = NSViewWidthSizable | NSViewHeightSizable;
+		[obj.contentView addSubview:view];
+		return view.layer;
+	}
+}

xmake.lua

@@ -103,6 +103,8 @@ local modules = {
 				add_defines("VK_USE_PLATFORM_WAYLAND_KHR")
 			elseif is_plat("macosx") then
 				add_defines("VK_USE_PLATFORM_METAL_EXT")
+				add_files("src/Nazara/VulkanRenderer/**.mm")
+				add_frameworks("quartzcore", "AppKit")
 			end
 		end
 	},