Refactor of GraphicsAdapter into partial class.

Implemented GraphicsAdapter for DirectX platforms.
Added unit tests for GraphicsAdapter.

Build/Projects/MonoGame.Framework.definition

@@ -604,7 +604,15 @@
 		<ExcludePlatforms>Web</ExcludePlatforms>
     </Compile>
     <Compile Include="Graphics\Effect\SpriteEffect.cs" />
-    <Compile Include="Graphics\GraphicsAdapter.cs" />
+    <Compile Include="Graphics\GraphicsAdapter.cs">
+      <ExcludePlatforms>Android,Angle,iOS,Linux,MacOS,Ouya,WindowsGL,tvOS,Web</ExcludePlatforms>
+    </Compile>
+    <Compile Include="Graphics\GraphicsAdapter.DirectX.cs">
+      <Services>DirectXGraphics</Services>
+    </Compile>
+    <Compile Include="Graphics\GraphicsAdapter.Legacy.cs">
+      <Platforms>Android,Angle,iOS,Linux,MacOS,Ouya,WindowsGL,tvOS,Web</Platforms>
+    </Compile>
     <Compile Include="Graphics\GraphicsCapabilities.cs" />
     <Compile Include="Graphics\GraphicsContext.SDL.cs">
       <Platforms>WindowsGL,Linux</Platforms>

Build/Projects/MonoGame.Tests.definition

@@ -98,6 +98,7 @@
     <Compile Include="Framework\GameTest+Methods.cs" />
     <Compile Include="Framework\GameTest+Properties.cs" />
     <Compile Include="Framework\GestureRecognizerTest.cs" />
+    <Compile Include="Framework\GraphicsAdapterTest.cs" />
     <Compile Include="Framework\MathHelperTest.cs" />
 	<Compile Include="Framework\MatrixTest.cs" />
     <Compile Include="Framework\MockWindow.cs" />

MonoGame.Framework/Graphics/DisplayMode.cs

@@ -118,7 +118,7 @@ public override int GetHashCode()
 
         public override string ToString()
         {
-            return "{{Width:" + this.width + " Height:" + this.height + " Format:" + this.Format + "}}";
+            return "{Width:" + this.width + " Height:" + this.height + " Format:" + this.Format + " AspectRatio:" + this.AspectRatio + "}";
         }
 
         #endregion Public Methods

MonoGame.Framework/Graphics/DisplayModeCollection.cs

@@ -33,38 +33,49 @@ MIT License
 
 namespace Microsoft.Xna.Framework.Graphics
 {
-    public class DisplayModeCollection : IEnumerable<DisplayMode>, IEnumerable
+    public class DisplayModeCollection : IEnumerable<DisplayMode>
     {
-        private readonly List<DisplayMode> modes;
+        private readonly List<DisplayMode> _modes;
 
         public IEnumerable<DisplayMode> this[SurfaceFormat format]
         {
-            get {
-                List<DisplayMode> list = new List<DisplayMode>();
-                foreach (DisplayMode mode in this.modes)
+            get 
+            {
+                var list = new List<DisplayMode>();
+                foreach (var mode in _modes)
                 {
                     if (mode.Format == format)
-                    {
                         list.Add(mode);
-                    }
                 }
                 return list;
-
             }
         }
 
         public IEnumerator<DisplayMode> GetEnumerator()
         {
-            return modes.GetEnumerator();
+            return _modes.GetEnumerator();
         }
 
         IEnumerator IEnumerable.GetEnumerator()
         {
-            return modes.GetEnumerator();
+            return _modes.GetEnumerator();
         }
 
-        public DisplayModeCollection(List<DisplayMode> setmodes) {
-            modes = setmodes;
+        internal DisplayModeCollection(List<DisplayMode> modes) 
+        {
+            // Sort the modes in a consistent way that happens
+            // to match XNA behavior on some graphics devices.
+
+            modes.Sort(delegate(DisplayMode a, DisplayMode b)
+            {
+                if (a == b) 
+                    return 0;
+                if (a.Format <= b.Format && a.Width <= b.Width && a.Height <= b.Height) 
+                    return -1;
+                return 1;
+            });
+
+            _modes = modes;
         }
     }
 }

MonoGame.Framework/Graphics/GraphicsAdapter.DirectX.cs

@@ -0,0 +1,93 @@
+// MonoGame - Copyright (C) The MonoGame Team
+// This file is subject to the terms and conditions defined in
+// file 'LICENSE.txt', which is part of this source code package.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+
+namespace Microsoft.Xna.Framework.Graphics
+{
+    partial class GraphicsAdapter
+    {
+        private static void PlatformInitializeAdapters(out ReadOnlyCollection<GraphicsAdapter> adapters)
+        {
+            var dxgiFactory = new SharpDX.DXGI.Factory1();
+
+            var adapterCount = dxgiFactory.GetAdapterCount();
+            var adapterList = new List<GraphicsAdapter>(adapterCount);
+
+            for (var i = 0; i < adapterCount; i++)
+            {
+                var dxgiAdapter = dxgiFactory.GetAdapter1(i);
+
+                var outputsCount = dxgiAdapter.GetOutputCount();
+                for (var j = 0; j < outputsCount; j++)
+                {
+                    var output = dxgiAdapter.GetOutput(j);
+
+                    var adapter = CreateAdapter(dxgiAdapter, output);
+                    adapterList.Add(adapter);
+
+                    output.Dispose();
+                }
+
+                dxgiAdapter.Dispose();
+            }
+
+            dxgiFactory.Dispose();
+
+            adapters = new ReadOnlyCollection<GraphicsAdapter>(adapterList);
+        }
+
+        private static readonly Dictionary<SharpDX.DXGI.Format, SurfaceFormat> FormatTranslations = new Dictionary<SharpDX.DXGI.Format, SurfaceFormat>
+        {
+            { SharpDX.DXGI.Format.R8G8B8A8_UNorm, SurfaceFormat.Color },
+            { SharpDX.DXGI.Format.B8G8R8A8_UNorm, SurfaceFormat.Color },
+            { SharpDX.DXGI.Format.B5G6R5_UNorm, SurfaceFormat.Bgr565 },
+        };
+
+        private static GraphicsAdapter CreateAdapter(SharpDX.DXGI.Adapter1 dxgiAdapter, SharpDX.DXGI.Output output)
+        {            
+            var adapter = new GraphicsAdapter();
+
+            adapter.DeviceName = output.Description.DeviceName;
+            adapter.Description = dxgiAdapter.Description1.Description;
+            adapter.DeviceId = dxgiAdapter.Description1.DeviceId;
+            adapter.Revision = dxgiAdapter.Description1.Revision;
+            adapter.VendorId = dxgiAdapter.Description1.VendorId;
+            adapter.SubSystemId = dxgiAdapter.Description1.SubsystemId;
+            adapter.MonitorHandle = output.Description.MonitorHandle;
+
+            var desktopWidth = output.Description.DesktopBounds.Width;
+            var desktopHeight = output.Description.DesktopBounds.Height;
+
+            var modes = new List<DisplayMode>();
+
+            foreach (var formatTranslation in FormatTranslations)
+            {
+                var displayModes = output.GetDisplayModeList(formatTranslation.Key, 0);
+                foreach (var displayMode in displayModes)
+                {
+                    var mode = new DisplayMode(displayMode.Width, displayMode.Height, formatTranslation.Value);
+
+                    // Skip duplicate modes with the same width/height/formats.
+                    if (modes.Contains(mode))
+                        continue;
+
+                    modes.Add(mode);
+
+                    if (mode.Width == desktopWidth && mode.Height == desktopHeight && mode.Format == SurfaceFormat.Color)
+                    {
+                        if (adapter._currentDisplayMode == null)
+                            adapter._currentDisplayMode = mode;
+                    }
+                }
+            }
+
+            adapter._supportedDisplayModes = new DisplayModeCollection(modes);
+
+            return adapter;
+        }
+    }
+}