change graphics backend selection behavior

MoonWorks.csproj

@@ -3,7 +3,6 @@
 	<PropertyGroup>
 		<TargetFramework>net8.0</TargetFramework>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-		<LangVersion>11</LangVersion>
 	</PropertyGroup>
 
 	<PropertyGroup>

lib/RefreshCS

@@ -1 +1 @@
-Subproject commit 859675dbab86e6eeda662ef9bdb0c688cce4cec3
+Subproject commit 55acf6ee1818b0801cffe7217ee07eb1f56016f6

src/Game.cs

@@ -53,11 +53,10 @@ namespace MoonWorks
 		public Game(
 			WindowCreateInfo windowCreateInfo,
 			FrameLimiterSettings frameLimiterSettings,
-			Backend backend = Backend.Vulkan,
+			Span<Backend> preferredBackends,
 			int targetTimestep = 60,
 			bool debugMode = false
-		)
-		{
+		) {
 			Logger.LogInfo("Initializing frame limiter...");
 			Timestep = TimeSpan.FromTicks(TimeSpan.TicksPerSecond / targetTimestep);
 			gameTimer = Stopwatch.StartNew();
@@ -83,7 +82,7 @@ namespace MoonWorks
 
 			Logger.LogInfo("Initializing graphics device...");
 			GraphicsDevice = new GraphicsDevice(
-				backend,
+				preferredBackends,
 				debugMode
 			);
 

src/Graphics/GraphicsDevice.cs

@@ -40,11 +40,17 @@ namespace MoonWorks.Graphics
 		private FencePool FencePool;
 		private CommandBufferPool CommandBufferPool;
 
-		internal GraphicsDevice(
-			Backend preferredBackend,
+		internal unsafe GraphicsDevice(
+			Span<Backend> preferredBackends,
 			bool debugMode
 		) {
-			Backend = (Backend) Refresh.Refresh_SelectBackend((Refresh.Backend) preferredBackend, out windowFlags);
+			var backends = stackalloc Refresh.Backend[preferredBackends.Length];
+			for (var i = 0; i < preferredBackends.Length; i += 1)
+			{
+				backends[i] = (Refresh.Backend) preferredBackends[i];
+			}
+
+			Backend = (Backend) Refresh.Refresh_SelectBackend(backends, (uint) preferredBackends.Length, out windowFlags);
 
 			if (Backend == Backend.Invalid)
 			{

src/Graphics/RefreshEnums.cs

@@ -311,7 +311,6 @@ namespace MoonWorks.Graphics
 
 	public enum Backend
 	{
-		DontCare,
 		Vulkan,
 		D3D11,
 		PS5,