[X11] Fix for issue #143

OpenTK will now use the same GLXFBConfig to create the INativeWindow
and IGraphicsContext on Linux/X11. This resolves an issue where OpenGL
3.x contexts could not be created on some graphics drivers (e.g.
nvidia binary.)

Source/OpenTK/Platform/Utilities.cs

@@ -248,11 +248,7 @@ namespace OpenTK.Platform
             window.Screen = screen;
             window.Handle = windowHandle;
             window.RootWindow = rootWindow;
-            if (visualInfo != IntPtr.Zero)
-            {
-                window.VisualInfo = (X11.XVisualInfo)Marshal.PtrToStructure(visualInfo, typeof(X11.XVisualInfo));
-            }
-
+            window.Visual = visualInfo;
             return window;
         }
 

Source/OpenTK/Platform/X11/X11GLContext.cs

@@ -78,13 +78,26 @@ namespace OpenTK.Platform.X11
                 }
             }
 
-            Mode = ModeSelector.SelectGraphicsMode(
-                mode.ColorFormat, mode.Depth, mode.Stencil, mode.Samples,
-                mode.AccumulatorFormat, mode.Buffers, mode.Stereo);
+            IntPtr visual = IntPtr.Zero;
+            IntPtr fbconfig = IntPtr.Zero;
 
+            // Once a window has a visual, we cannot use a different
+            // visual on the OpenGL context, or glXMakeCurrent might fail.
+            // Note: we should only check X11WindowInfo.Visual, as that
+            // is the only property that can be set by Utilities.CreateX11WindowInfo.
             currentWindow = (X11WindowInfo)window;
-            currentWindow.VisualInfo = SelectVisual(Mode, currentWindow);
-            
+            if (currentWindow.Visual != IntPtr.Zero)
+            {
+                visual = currentWindow.Visual;
+                fbconfig = currentWindow.FBConfig;
+                Mode = currentWindow.GraphicsMode;
+            }
+
+            if (!Mode.Index.HasValue)
+            {
+                Mode = ModeSelector.SelectGraphicsMode(mode, out visual, out fbconfig);
+            }
+
             ContextHandle shareHandle = shared != null ?
                 (shared as IGraphicsContextInternal).Context : (ContextHandle)IntPtr.Zero;
             
@@ -99,84 +112,15 @@ namespace OpenTK.Platform.X11
             // HACK: It seems that Catalyst 9.1 - 9.4 on Linux have problems with contexts created through
             // GLX_ARB_create_context, including hideous input lag, no vsync and other madness.
             // Use legacy context creation if the user doesn't request a 3.0+ context.
-            if ((major * 10 + minor >= 30) && SupportsCreateContextAttribs(Display, currentWindow))
+            if (fbconfig != IntPtr.Zero && (major * 10 + minor >= 30) && SupportsCreateContextAttribs(Display, currentWindow))
             {
-                Debug.Write("Using GLX_ARB_create_context... ");
-                
-                unsafe
-                {
-                    // We need the FB config for the current GraphicsMode.
-                    int count;
-                    IntPtr* fbconfigs = Glx.ChooseFBConfig(Display, currentWindow.Screen,
-                        new int[] {
-                        (int)GLXAttribute.VISUAL_ID,
-                        (int)Mode.Index,
-                        0
-                    }, out count);
-                    
-                    if (count > 0)
-                    {
-                        List<int> attributes = new List<int>();
-                        attributes.Add((int)ArbCreateContext.MajorVersion);
-                        attributes.Add(major);
-                        attributes.Add((int)ArbCreateContext.MinorVersion);
-                        attributes.Add(minor);
-                        if (flags != 0)
-                        {
-                            attributes.Add((int)ArbCreateContext.Flags);
-                            attributes.Add((int)GetARBContextFlags(flags));
-                            attributes.Add((int)ArbCreateContext.ProfileMask);
-                            attributes.Add((int)GetARBProfileFlags(flags));
-                        }
-                        // According to the docs, " <attribList> specifies a list of attributes for the context.
-                        // The list consists of a sequence of <name,value> pairs terminated by the
-                        // value 0. [...]"
-                        // Is this a single 0, or a <0, 0> pair? (Defensive coding: add two zeroes just in case).
-                        attributes.Add(0);
-                        attributes.Add(0);
-
-                        using (new XLock(Display))
-                        {
-                            Handle = new ContextHandle(Glx.Arb.CreateContextAttribs(Display, *fbconfigs,
-                                    shareHandle.Handle, direct, attributes.ToArray()));
-
-                            if (Handle == ContextHandle.Zero)
-                            {
-                                Debug.Write(String.Format("failed. Trying direct: {0}... ", !direct));
-                                Handle = new ContextHandle(Glx.Arb.CreateContextAttribs(Display, *fbconfigs,
-                                        shareHandle.Handle, !direct, attributes.ToArray()));
-                            }
-                        }
-                        
-                        if (Handle == ContextHandle.Zero)
-                            Debug.WriteLine("failed.");
-                        else
-                            Debug.WriteLine("success!");
-                        
-                        using (new XLock(Display))
-                        {
-                            Functions.XFree((IntPtr)fbconfigs);
-                        }
-                    }
-                }
+                Handle = CreateContextAttribs(Display, currentWindow.Screen,
+                    fbconfig, direct, major, minor, flags, shareHandle);
             }
             
             if (Handle == ContextHandle.Zero)
             {
-                Debug.Write("Using legacy context creation... ");
-                
-                XVisualInfo info = currentWindow.VisualInfo;
-                using (new XLock(Display))
-                {
-                    // Cannot pass a Property by reference.
-                    Handle = new ContextHandle(Glx.CreateContext(Display, ref info, shareHandle.Handle, direct));
-
-                    if (Handle == ContextHandle.Zero)
-                    {
-                        Debug.WriteLine(String.Format("failed. Trying direct: {0}... ", !direct));
-                        Handle = new ContextHandle(Glx.CreateContext(Display, ref info, IntPtr.Zero, !direct));
-                    }
-                }
+                Handle = CreateContextLegacy(Display, currentWindow.VisualInfo, direct, shareHandle);
             }
             
             if (Handle != ContextHandle.Zero)
@@ -208,6 +152,74 @@ namespace OpenTK.Platform.X11
 
         #region --- Private Methods ---
 
+        static ContextHandle CreateContextAttribs(
+            IntPtr display, int screen, IntPtr fbconfig,
+            bool direct, int major, int minor,
+            GraphicsContextFlags flags, ContextHandle shareContext)
+        {
+            Debug.Write("Using GLX_ARB_create_context... ");
+            IntPtr context = IntPtr.Zero;
+
+            {
+                // We need the FB config for the current GraphicsMode.
+                List<int> attributes = new List<int>();
+                attributes.Add((int)ArbCreateContext.MajorVersion);
+                attributes.Add(major);
+                attributes.Add((int)ArbCreateContext.MinorVersion);
+                attributes.Add(minor);
+                if (flags != 0)
+                {
+                    attributes.Add((int)ArbCreateContext.Flags);
+                    attributes.Add((int)GetARBContextFlags(flags));
+                    attributes.Add((int)ArbCreateContext.ProfileMask);
+                    attributes.Add((int)GetARBProfileFlags(flags));
+                }
+                // According to the docs, " <attribList> specifies a list of attributes for the context.
+                // The list consists of a sequence of <name,value> pairs terminated by the
+                // value 0. [...]"
+                // Is this a single 0, or a <0, 0> pair? (Defensive coding: add two zeroes just in case).
+                attributes.Add(0);
+                attributes.Add(0);
+
+                using (new XLock(display))
+                {
+                    context = Glx.Arb.CreateContextAttribs(display, fbconfig, shareContext.Handle, direct, attributes.ToArray());
+                    if (context == IntPtr.Zero)
+                    {
+                        Debug.Write(String.Format("failed. Trying direct: {0}... ", !direct));
+                        context = Glx.Arb.CreateContextAttribs(display, fbconfig, shareContext.Handle, !direct, attributes.ToArray());
+                    }
+                }
+
+                if (context == IntPtr.Zero)
+                    Debug.WriteLine("failed.");
+                else
+                    Debug.WriteLine("success!");
+            }
+
+            return new ContextHandle(context);
+        }
+
+        static ContextHandle CreateContextLegacy(IntPtr display,
+            XVisualInfo info, bool direct, ContextHandle shareContext)
+        {
+            Debug.Write("Using legacy context creation... ");
+            IntPtr context;
+
+            using (new XLock(display))
+            {
+                // Cannot pass a Property by reference.
+                context = Glx.CreateContext(display, ref info, shareContext.Handle, direct);
+                if (context == IntPtr.Zero)
+                {
+                    Debug.WriteLine(String.Format("failed. Trying direct: {0}... ", !direct));
+                    context = Glx.CreateContext(display, ref info, IntPtr.Zero, !direct);
+                }
+            }
+
+            return new ContextHandle(context);
+        }
+
         IntPtr Display
         {
             get { return display; }
@@ -221,38 +233,14 @@ namespace OpenTK.Platform.X11
             }
         }
 
-        #region XVisualInfo SelectVisual(GraphicsMode mode, X11WindowInfo currentWindow)
-
-        XVisualInfo SelectVisual(GraphicsMode mode, X11WindowInfo currentWindow)
-        {
-            XVisualInfo info = new XVisualInfo();
-            info.VisualID = (IntPtr)mode.Index;
-            info.Screen = currentWindow.Screen;
-            int items;
-            
-            lock (API.Lock)
-            {
-                IntPtr vs = Functions.XGetVisualInfo(Display, XVisualInfoMask.ID | XVisualInfoMask.Screen, ref info, out items);
-                if (items == 0)
-                    throw new GraphicsModeException(String.Format("Invalid GraphicsMode specified ({0}).", mode));
-
-                info = (XVisualInfo)Marshal.PtrToStructure(vs, typeof(XVisualInfo));
-                Functions.XFree(vs);
-            }
-
-            return info;
-        }
-
-        #endregion
-
-        ArbCreateContext GetARBContextFlags(GraphicsContextFlags flags)
+        static ArbCreateContext GetARBContextFlags(GraphicsContextFlags flags)
         {
             ArbCreateContext result = 0;
             result |= (flags & GraphicsContextFlags.Debug) != 0 ? ArbCreateContext.DebugBit : 0;
             return result;
         }
 
-        ArbCreateContext GetARBProfileFlags(GraphicsContextFlags flags)
+        static ArbCreateContext GetARBProfileFlags(GraphicsContextFlags flags)
         {
             ArbCreateContext result = 0;
             result |= (flags & GraphicsContextFlags.ForwardCompatible) != 0 ?

Source/OpenTK/Platform/X11/X11GLNative.cs

@@ -140,7 +140,7 @@ namespace OpenTK.Platform.X11
         #region Constructors
 
         public X11GLNative(int x, int y, int width, int height, string title,
-            GraphicsMode mode,GameWindowFlags options, DisplayDevice device)
+            GraphicsMode mode, GameWindowFlags options, DisplayDevice device)
             : this()
         {
             if (width <= 0)
@@ -154,17 +154,13 @@ namespace OpenTK.Platform.X11
             
             using (new XLock(window.Display))
             {
-                if (!mode.Index.HasValue)
-                {
-                    mode = new X11GraphicsMode().SelectGraphicsMode(
-                        mode.ColorFormat, mode.Depth, mode.Stencil, mode.Samples,
-                        mode.AccumulatorFormat, mode.Buffers, mode.Stereo);
-                }
+                IntPtr visual;
+                IntPtr fbconfig;
+                window.GraphicsMode = new X11GraphicsMode()
+                    .SelectGraphicsMode(mode, out visual, out fbconfig);
 
-                info.VisualID = mode.Index.Value;
-                int dummy;
-                window.VisualInfo = (XVisualInfo)Marshal.PtrToStructure(
-                    Functions.XGetVisualInfo(window.Display, XVisualInfoMask.ID, ref info, out dummy), typeof(XVisualInfo));
+                window.Visual = visual;
+                window.FBConfig = fbconfig;
 
                 // Create a window on this display using the visual above
                 Debug.Write("Opening render window... ");

Source/OpenTK/Platform/X11/X11GraphicsMode.cs

@@ -16,7 +16,7 @@ using OpenTK.Graphics;
 
 namespace OpenTK.Platform.X11
 {
-    class X11GraphicsMode : IGraphicsMode
+    class X11GraphicsMode
     {
         // Todo: Add custom visual selection algorithm, instead of ChooseFBConfig/ChooseVisual.
         // It seems the Choose* methods do not take multisampling into account (at least on some
@@ -32,34 +32,45 @@ namespace OpenTK.Platform.X11
 
         #region IGraphicsMode Members
 
-        public GraphicsMode SelectGraphicsMode(ColorFormat color, int depth, int stencil, int samples, ColorFormat accum,
-                                               int buffers, bool stereo)
+        public GraphicsMode SelectGraphicsMode(GraphicsMode desired_mode, out IntPtr visual, out IntPtr fbconfig)
         {
             GraphicsMode gfx;
-            // The actual GraphicsMode that will be selected.
-            IntPtr visual = IntPtr.Zero;
+            GraphicsMode mode = new GraphicsMode(desired_mode);
+            visual = IntPtr.Zero;
+            fbconfig = IntPtr.Zero;
             IntPtr display = API.DefaultDisplay;
 
             do
             {
                 // Try to select a visual using Glx.ChooseFBConfig and Glx.GetVisualFromFBConfig.
                 // This is only supported on GLX 1.3 - if it fails, fall back to Glx.ChooseVisual.
-                visual = SelectVisualUsingFBConfig(color, depth, stencil, samples, accum, buffers, stereo);
+                fbconfig = SelectFBConfig(mode);
+                if (fbconfig != IntPtr.Zero)
+                    visual = Glx.GetVisualFromFBConfig(display, fbconfig);
                 
                 if (visual == IntPtr.Zero)
-                    visual = SelectVisualUsingChooseVisual(color, depth, stencil, samples, accum, buffers, stereo);
+                    visual = SelectVisual(mode);
                 
                 if (visual == IntPtr.Zero)
                 {
                     // Relax parameters and retry
-                    if (!Utilities.RelaxGraphicsMode(ref color, ref depth, ref stencil, ref samples, ref accum, ref buffers, ref stereo))
+                    if (!Utilities.RelaxGraphicsMode(ref mode))
                         throw new GraphicsModeException("Requested GraphicsMode not available.");
                 }
             }
             while (visual == IntPtr.Zero);
 
             XVisualInfo info = (XVisualInfo)Marshal.PtrToStructure(visual, typeof(XVisualInfo));
+            gfx = CreateGraphicsMode(display, ref info);
+            return gfx;
+        }
 
+        #endregion
+
+        #region Private Members
+
+        static GraphicsMode CreateGraphicsMode(IntPtr display, ref XVisualInfo info)
+        {
             // See what we *really* got:
             int r, g, b, a;
             Glx.GetConfig(display, ref info, GLXAttribute.ALPHA_SIZE, out a);
@@ -71,99 +82,84 @@ namespace OpenTK.Platform.X11
             Glx.GetConfig(display, ref info, GLXAttribute.ACCUM_RED_SIZE, out ar);
             Glx.GetConfig(display, ref info, GLXAttribute.ACCUM_GREEN_SIZE, out ag);
             Glx.GetConfig(display, ref info, GLXAttribute.ACCUM_BLUE_SIZE, out ab);
+            int depth, stencil, samples, buffers;
             Glx.GetConfig(display, ref info, GLXAttribute.DEPTH_SIZE, out depth);
             Glx.GetConfig(display, ref info, GLXAttribute.STENCIL_SIZE, out stencil);
             Glx.GetConfig(display, ref info, GLXAttribute.SAMPLES, out samples);
             Glx.GetConfig(display, ref info, GLXAttribute.DOUBLEBUFFER, out buffers);
-            ++buffers;
-            // the above lines returns 0 - false and 1 - true.
             int st;
             Glx.GetConfig(display, ref info, GLXAttribute.STEREO, out st);
-            stereo = st != 0;
-            
-            gfx = new GraphicsMode(info.VisualID, new ColorFormat(r, g, b, a), depth, stencil, samples,
-            new ColorFormat(ar, ag, ab, aa), buffers, stereo);
-            
-            using (new XLock(display))
-            {
-                Functions.XFree(visual);
-            }
-            
-            return gfx;
+
+            // Note: Glx.GetConfig return buffers = 0 (false) or 1 (true).
+            // OpenTK expects buffers = 1 (single-) or 2 (double-buffering),
+            // so increase the GLX value by one.
+            return new GraphicsMode(info.VisualID, new ColorFormat(r, g, b, a), depth, stencil, samples,
+                new ColorFormat(ar, ag, ab, aa), buffers + 1, st != 0);
         }
 
-        #endregion
-
-        #region Private Members
-
-        // See http://publib.boulder.ibm.com/infocenter/systems/index.jsp?topic=/com.ibm.aix.opengl/doc/openglrf/glXChooseFBConfig.htm
-        // for the attribute declarations. Note that the attributes are different than those used in Glx.ChooseVisual.
-        IntPtr SelectVisualUsingFBConfig(ColorFormat color, int depth, int stencil, int samples, ColorFormat accum,
-                                               int buffers, bool stereo)
+        IntPtr SelectFBConfig(GraphicsMode mode)
         {
+            Debug.Print("Selecting FB config for {0}", mode);
+
             List<int> visualAttributes = new List<int>();
             IntPtr visual = IntPtr.Zero;
 
-            Debug.Print("Bits per pixel: {0}", color.BitsPerPixel);
-
-            if (color.BitsPerPixel > 0)
+            if (mode.ColorFormat.BitsPerPixel > 0)
             {
-                if (!color.IsIndexed)
+                if (!mode.ColorFormat.IsIndexed)
                 {
-                    visualAttributes.Add((int)GLXAttribute.RGBA);
-                    visualAttributes.Add(1);
+                    visualAttributes.Add((int)GLXAttribute.RENDER_TYPE);
+                    visualAttributes.Add((int)GLXRenderTypeMask.RGBA_BIT);
                 }
                 visualAttributes.Add((int)GLXAttribute.RED_SIZE);
-                visualAttributes.Add(color.Red);
+                visualAttributes.Add(mode.ColorFormat.Red);
                 visualAttributes.Add((int)GLXAttribute.GREEN_SIZE);
-                visualAttributes.Add(color.Green);
+                visualAttributes.Add(mode.ColorFormat.Green);
                 visualAttributes.Add((int)GLXAttribute.BLUE_SIZE);
-                visualAttributes.Add(color.Blue);
+                visualAttributes.Add(mode.ColorFormat.Blue);
                 visualAttributes.Add((int)GLXAttribute.ALPHA_SIZE);
-                visualAttributes.Add(color.Alpha);
+                visualAttributes.Add(mode.ColorFormat.Alpha);
             }
 
-            Debug.Print("Depth: {0}", depth);
-
-            if (depth > 0)
+            if (mode.Depth > 0)
             {
                 visualAttributes.Add((int)GLXAttribute.DEPTH_SIZE);
-                visualAttributes.Add(depth);
+                visualAttributes.Add(mode.Depth);
             }
 
-            if (buffers > 1)
+            if (mode.Buffers > 1)
             {
                 visualAttributes.Add((int)GLXAttribute.DOUBLEBUFFER);
                 visualAttributes.Add(1);
             }
 
-            if (stencil > 1)
+            if (mode.Stereo)
             {
                 visualAttributes.Add((int)GLXAttribute.STENCIL_SIZE);
-                visualAttributes.Add(stencil);
+                visualAttributes.Add(mode.Stereo ? 1 : 0);
             }
 
-            if (accum.BitsPerPixel > 0)
+            if (mode.AccumulatorFormat.BitsPerPixel > 0)
             {
                 visualAttributes.Add((int)GLXAttribute.ACCUM_ALPHA_SIZE);
-                visualAttributes.Add(accum.Alpha);
+                visualAttributes.Add(mode.AccumulatorFormat.Alpha);
                 visualAttributes.Add((int)GLXAttribute.ACCUM_BLUE_SIZE);
-                visualAttributes.Add(accum.Blue);
+                visualAttributes.Add(mode.AccumulatorFormat.Blue);
                 visualAttributes.Add((int)GLXAttribute.ACCUM_GREEN_SIZE);
-                visualAttributes.Add(accum.Green);
+                visualAttributes.Add(mode.AccumulatorFormat.Green);
                 visualAttributes.Add((int)GLXAttribute.ACCUM_RED_SIZE);
-                visualAttributes.Add(accum.Red);
+                visualAttributes.Add(mode.AccumulatorFormat.Red);
             }
-            
-            if (samples > 0)
+
+            if (mode.Samples > 0)
             {
                 visualAttributes.Add((int)GLXAttribute.SAMPLE_BUFFERS);
                 visualAttributes.Add(1);
                 visualAttributes.Add((int)GLXAttribute.SAMPLES);
-                visualAttributes.Add(samples);
+                visualAttributes.Add(mode.Samples);
             }
 
-            if (stereo)
+            if (mode.Stereo)
             {
                 visualAttributes.Add((int)GLXAttribute.STEREO);
                 visualAttributes.Add(1);
@@ -173,6 +169,7 @@ namespace OpenTK.Platform.X11
 
             // Select a visual that matches the parameters set by the user.
             IntPtr display = API.DefaultDisplay;
+            IntPtr result = IntPtr.Zero;
             using (new XLock(display))
             {
                 try
@@ -180,7 +177,7 @@ namespace OpenTK.Platform.X11
                     int screen = Functions.XDefaultScreen(display);
                     IntPtr root = Functions.XRootWindow(display, screen);
                     Debug.Print("Display: {0}, Screen: {1}, RootWindow: {2}", display, screen, root);
-    
+
                     unsafe
                     {
                         Debug.Print("Getting FB config.");
@@ -190,81 +187,82 @@ namespace OpenTK.Platform.X11
                         if (fbcount > 0 && fbconfigs != null)
                         {
                             // We want to use the first GLXFBConfig from the fbconfigs array (the first one is the best match).
-                            visual = Glx.GetVisualFromFBConfig(display, *fbconfigs);
+                            Debug.Print("Selected FB config: {0}", *fbconfigs);
+                            result = *fbconfigs;
                             Functions.XFree((IntPtr)fbconfigs);
                         }
+                        else
+                        {
+                            Debug.Print("No matching FB config found.");
+                        }
                     }
                 }
                 catch (EntryPointNotFoundException)
                 {
                     Debug.Print("Function glXChooseFBConfig not supported.");
-                    return IntPtr.Zero;
                 }
             }
 
-            return visual;
+            return result;
         }
 
-        // See http://publib.boulder.ibm.com/infocenter/systems/index.jsp?topic=/com.ibm.aix.opengl/doc/openglrf/glXChooseVisual.htm
-        IntPtr SelectVisualUsingChooseVisual(ColorFormat color, int depth, int stencil, int samples, ColorFormat accum,
-                                                  int buffers, bool stereo)
+        IntPtr SelectVisual(GraphicsMode mode)
         {
+            Debug.Print("Selecting FB config for {0}", mode);
+
             List<int> visualAttributes = new List<int>();
 
-            Debug.Print("Bits per pixel: {0}", color.BitsPerPixel);
-
-            if (color.BitsPerPixel > 0)
+            if (mode.ColorFormat.BitsPerPixel > 0)
             {
-                if (!color.IsIndexed)
+                if (!mode.ColorFormat.IsIndexed)
                     visualAttributes.Add((int)GLXAttribute.RGBA);
                 visualAttributes.Add((int)GLXAttribute.RED_SIZE);
-                visualAttributes.Add(color.Red);
+                visualAttributes.Add(mode.ColorFormat.Red);
                 visualAttributes.Add((int)GLXAttribute.GREEN_SIZE);
-                visualAttributes.Add(color.Green);
+                visualAttributes.Add(mode.ColorFormat.Green);
                 visualAttributes.Add((int)GLXAttribute.BLUE_SIZE);
-                visualAttributes.Add(color.Blue);
+                visualAttributes.Add(mode.ColorFormat.Blue);
                 visualAttributes.Add((int)GLXAttribute.ALPHA_SIZE);
-                visualAttributes.Add(color.Alpha);
+                visualAttributes.Add(mode.ColorFormat.Alpha);
             }
 
-            Debug.Print("Depth: {0}", depth);
 
-            if (depth > 0)
+            if (mode.Depth > 0)
             {
                 visualAttributes.Add((int)GLXAttribute.DEPTH_SIZE);
-                visualAttributes.Add(depth);
+                visualAttributes.Add(mode.Depth);
             }
 
-            if (buffers > 1)
+            if (mode.Buffers > 1)
                 visualAttributes.Add((int)GLXAttribute.DOUBLEBUFFER);
 
-            if (stencil > 1)
+            if (mode.Stencil > 1)
             {
                 visualAttributes.Add((int)GLXAttribute.STENCIL_SIZE);
-                visualAttributes.Add(stencil);
+                visualAttributes.Add(mode.Stencil);
             }
 
-            if (accum.BitsPerPixel > 0)
+            if (mode.AccumulatorFormat.BitsPerPixel > 0)
             {
                 visualAttributes.Add((int)GLXAttribute.ACCUM_ALPHA_SIZE);
-                visualAttributes.Add(accum.Alpha);
+                visualAttributes.Add(mode.AccumulatorFormat.Alpha);
                 visualAttributes.Add((int)GLXAttribute.ACCUM_BLUE_SIZE);
-                visualAttributes.Add(accum.Blue);
+                visualAttributes.Add(mode.AccumulatorFormat.Blue);
                 visualAttributes.Add((int)GLXAttribute.ACCUM_GREEN_SIZE);
-                visualAttributes.Add(accum.Green);
+                visualAttributes.Add(mode.AccumulatorFormat.Green);
                 visualAttributes.Add((int)GLXAttribute.ACCUM_RED_SIZE);
-                visualAttributes.Add(accum.Red);
+                visualAttributes.Add(mode.AccumulatorFormat.Red);
             }
-            
-            if (samples > 0)
+
+            if (mode.Samples > 0)
             {
                 visualAttributes.Add((int)GLXAttribute.SAMPLE_BUFFERS);
                 visualAttributes.Add(1);
                 visualAttributes.Add((int)GLXAttribute.SAMPLES);
-                visualAttributes.Add(samples);
+                visualAttributes.Add(mode.Samples);
             }
 
-            if (stereo)
+            if (mode.Stereo)
                 visualAttributes.Add((int)GLXAttribute.STEREO);
 
             visualAttributes.Add(0);

Source/OpenTK/Platform/X11/X11WindowInfo.cs

@@ -27,6 +27,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Runtime.InteropServices;
 using System.Text;
 
 namespace OpenTK.Platform.X11
@@ -87,7 +88,17 @@ namespace OpenTK.Platform.X11
         /// <summary>Gets or sets the X11 screen.</summary>
         public int Screen { get { return screen; } set { screen = value; } }
         /// <summary>Gets or sets the X11 VisualInfo.</summary>
-        public XVisualInfo VisualInfo { get { return visualInfo; } set { visualInfo = value; } }
+        public XVisualInfo VisualInfo
+        {
+            get
+            {
+                if (Visual != IntPtr.Zero)
+                {
+                    return (XVisualInfo)Marshal.PtrToStructure(Visual, typeof(XVisualInfo));
+                }
+                return default(XVisualInfo);
+            }
+        }
         /// <summary>Gets or sets the X11 EventMask.</summary>
         public EventMask EventMask { get { return eventMask; } set { eventMask = value; } }
 
@@ -96,6 +107,10 @@ namespace OpenTK.Platform.X11
         // (e.g. MonoGame)
         public IntPtr WindowHandle { get { return Handle; } set { Handle = value; } }
 
+        public IntPtr Visual { get; set; }
+        public IntPtr FBConfig { get; set; }
+        public Graphics.GraphicsMode GraphicsMode { get; set; }
+
         #endregion
 
         #region --- IDisposable Members ---