Fix compilation errors: Remove invalid GraphicsDevice properties and implement missing WPF handler method

Co-authored-by: philstopford <1983851+philstopford@users.noreply.github.com>

Author: Copilot

Eto/Eto.Veldrid.Gtk/Examples/BackendSwitchingExample.cs

@@ -102,9 +102,9 @@ private void ShowBackendInfo()
                       $"Device: {device?.DeviceName}\n" +
                       $"Vendor: {device?.VendorName}\n" +
                       $"API Version: {device?.ApiVersion}\n" +
-                      $"Driver: {device?.DriverName} {device?.DriverInfo}\n" +
                       $"Uniform Buffer Alignment: {device?.UniformBufferMinOffsetAlignment}\n" +
-                      $"Max Texture Size: {device?.GetPixelFormatSupport(PixelFormat.R8G8B8A8UNorm, TextureType.Texture2D, TextureUsage.Sampled)}";
+                      $"UV Origin Top Left: {device?.IsUvOriginTopLeft}\n" +
+                      $"Depth Range Zero To One: {device?.IsDepthRangeZeroToOne}";
 
             MessageBox.Show(this, info, "Backend Information");
         }

Eto/Eto.Veldrid.Wpf/WpfVeldridSurfaceHandler.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Runtime.InteropServices;
 using Veldrid;
+using Veldrid.OpenGL;
 
 [assembly: Eto.ExportHandler(typeof(VeldridSurface), typeof(WpfVeldridSurfaceHandler))]
 
@@ -20,6 +21,51 @@ public WpfVeldridSurfaceHandler() : base(new WinFormsVeldridUserControl())
 			Control.Loaded += Control_Loaded;
 		}
 
+		public void InitializeGraphicsDevice(VeldridSurface surface, InitializeEventArgs e)
+		{
+			switch (surface.Backend)
+			{
+				case GraphicsBackend.Metal:
+					surface.GraphicsDevice = GraphicsDevice.CreateMetal(surface.GraphicsDeviceOptions);
+					break;
+				case GraphicsBackend.Direct3D11:
+					surface.GraphicsDevice = GraphicsDevice.CreateD3D11(surface.GraphicsDeviceOptions);
+					break;
+				case GraphicsBackend.Vulkan:
+					surface.GraphicsDevice = GraphicsDevice.CreateVulkan(surface.GraphicsDeviceOptions);
+					break;
+				case GraphicsBackend.OpenGL:
+					surface.GraphicsDevice = GraphicsDevice.CreateOpenGL(
+						surface.GraphicsDeviceOptions,
+						new OpenGLPlatformInfo(
+							surface.OpenGL.OpenGLContextHandle,
+							surface.OpenGL.GetProcAddress,
+							surface.OpenGL.MakeCurrent,
+							surface.OpenGL.GetCurrentContext,
+							surface.OpenGL.ClearCurrentContext,
+							surface.OpenGL.DeleteContext,
+							surface.OpenGL.SwapBuffers,
+							surface.OpenGL.SetSyncToVerticalBlank,
+							surface.OpenGL.SetSwapchainFramebuffer,
+							surface.OpenGL.ResizeSwapchain),
+						(uint)e.Width,
+						(uint)e.Height);
+					break;
+				default:
+					string message;
+					if (!Enum.IsDefined(typeof(GraphicsBackend), surface.Backend))
+					{
+						message = "Unrecognized backend!";
+					}
+					else
+					{
+						message = "Specified backend not supported on this platform!";
+					}
+
+					throw new ArgumentException(message);
+			}
+		}
+
 		public Swapchain? CreateSwapchain()
 		{
 			Swapchain? swapchain;