initial refresh backend selection API support

lib/RefreshCS

@@ -1 +1 @@
-Subproject commit 356f8e9ec2a6118b75e32d2a2ed7dbf4297aba78
+Subproject commit eaed76f4dcc60022b3f10997fb34eb8ead9ae7d7

src/Game.cs

@@ -79,6 +79,7 @@ namespace MoonWorks
 
 			GraphicsDevice = new GraphicsDevice(
 				Window.Handle,
+				Backend.Vulkan,
 				moonWorksToRefreshPresentMode[presentMode],
 				debugMode
 			);

src/Graphics/GraphicsDevice.cs

@@ -8,6 +8,7 @@ namespace MoonWorks.Graphics
 	public class GraphicsDevice : IDisposable
 	{
 		public IntPtr Handle { get; }
+		public Backend Backend { get; }
 
 		// Built-in video pipeline
 		private ShaderModule VideoVertexShader { get; }
@@ -20,10 +21,13 @@ namespace MoonWorks.Graphics
 
 		public GraphicsDevice(
 			IntPtr deviceWindowHandle,
+			Backend preferredBackend,
 			Refresh.PresentMode presentMode,
 			bool debugMode
 		)
 		{
+			Backend = (Backend) Refresh.Refresh_SelectBackend((Refresh.Backend) preferredBackend, out uint flags);
+
 			var presentationParameters = new Refresh.PresentationParameters
 			{
 				deviceWindowHandle = deviceWindowHandle,

src/Graphics/RefreshEnums.cs

@@ -280,4 +280,12 @@ namespace MoonWorks.Graphics
 		FloatOpaqueWhite,
 		IntOpaqueWhite
 	}
+
+	public enum Backend
+	{
+		DontCare,
+		Vulkan,
+		PS5,
+		Invalid
+	}
 }