Modified GraphicsMode.Index to be a nullable property. Modified consuming classes to check Index.HasValue prior to first use.

Source/OpenTK/Graphics/GraphicsMode.cs

@@ -19,7 +19,7 @@ namespace OpenTK.Graphics
         ColorFormat color_format, accumulator_format;
         int depth, stencil, buffers, samples;
         bool stereo;
-        IntPtr? index;  // The id of the pixel format or visual.
+        IntPtr? index = null;  // The id of the pixel format or visual.
 
         static GraphicsMode defaultMode;
         static IGraphicsMode implementation;
@@ -43,9 +43,9 @@ namespace OpenTK.Graphics
 
         #endregion
 
-        #region internal GraphicsMode((IntPtr index, ColorFormat color, int depth, int stencil, int samples, ColorFormat accum, int buffers, bool stereo)
+        #region internal GraphicsMode(IntPtr? index, ColorFormat color, int depth, int stencil, int samples, ColorFormat accum, int buffers, bool stereo)
 
-        internal GraphicsMode(IntPtr index, ColorFormat color, int depth, int stencil, int samples, ColorFormat accum,
+        internal GraphicsMode(IntPtr? index, ColorFormat color, int depth, int stencil, int samples, ColorFormat accum,
                               int buffers, bool stereo)
         {
             if (depth < 0) throw new ArgumentOutOfRangeException("depth", "Must be greater than, or equal to zero.");
@@ -160,7 +160,7 @@ namespace OpenTK.Graphics
         /// <param name="stereo">Set to true for a GraphicsMode with stereographic capabilities.</param>
         /// <param name="buffers">The number of render buffers. Typical values include one (single-), two (double-) or three (triple-buffering).</param>
         public GraphicsMode(ColorFormat color, int depth, int stencil, int samples, ColorFormat accum, int buffers, bool stereo)
-            : this(IntPtr.Zero, color, depth, stencil, samples, accum, buffers, stereo) { }
+            : this(null, color, depth, stencil, samples, accum, buffers, stereo) { }
 
         #endregion
 
@@ -287,7 +287,7 @@ namespace OpenTK.Graphics
 
         #region internal IntPtr Index
 
-        internal IntPtr Index
+        internal IntPtr? Index
         {
             get
             {
@@ -309,7 +309,7 @@ namespace OpenTK.Graphics
                     Stereo = mode.Stereo;
                 }
 
-                return index.Value;
+                return index;
             }
             set { index = value; }
         }

Source/OpenTK/Platform/Egl/EglContext.cs

@@ -29,14 +29,15 @@ using System;
 
 using OpenTK.Graphics;
 using System.Diagnostics;
+using OpenTK.Platform.Windows;
 
 namespace OpenTK.Platform.Egl
 {
-    class EglContext : IGraphicsContext
+    class EglContext : IGraphicsContext, IGraphicsContextInternal
     {
         #region Fields
 
-        EglWindowInfo window;
+        EglWindowInfo WindowInfo;
         EGLContext context;
         GraphicsMode mode;
         bool vsync = true;   // Default vsync value is defined as 1 (true) in EGL.
@@ -56,14 +57,23 @@ namespace OpenTK.Platform.Egl
 
             EglContext shared = (EglContext)sharedContext;
 
-            Egl.Initialize(window.Display, out major, out minor);
+            int dummy_major, dummy_minor;
+            if (!Egl.Initialize(window.Display, out dummy_major, out dummy_minor))
+                throw new GraphicsContextException(String.Format("Failed to initialize EGL, error {0}.", Egl.GetError()));
 
-            EGLConfig config = new EGLConfig(mode.Index);
+            WindowInfo = window;
+
+            mode = new EglGraphicsMode().SelectGraphicsMode(mode.ColorFormat, mode.Depth, mode.Stencil, mode.Samples, mode.AccumulatorFormat, mode.Buffers, mode.Stereo);
+            if (!mode.Index.HasValue)
+                throw new GraphicsModeException("Invalid or unsupported GraphicsMode.");
+            EGLConfig config = new EGLConfig(mode.Index.Value);
 
             if (window.Surface.Handle == EGLSurface.None.Handle)
                 window.CreateWindowSurface(config);
 
-            context = Egl.CreateContext(window.Display, config, shared.context, null);
+            int[] attrib_list = new int[] { Egl.CONTEXT_CLIENT_VERSION, major, Egl.NONE };
+            context = Egl.CreateContext(window.Display, config, shared != null ? shared.context : EGLContext.None, attrib_list);
+
             MakeCurrent(window);
         }
 
@@ -73,14 +83,18 @@ namespace OpenTK.Platform.Egl
 
         public void SwapBuffers()
         {
-            Egl.SwapBuffers(window.Display, window.Surface);
+            Egl.SwapBuffers(WindowInfo.Display, WindowInfo.Surface);
         }
 
         public void MakeCurrent(IWindowInfo window)
         {
-            EglWindowInfo egl = (EglWindowInfo)window;
+            // Ignore 'window', unless it actually is an EGL window. In other words,
-            Egl.MakeCurrent(egl.Display, egl.Surface, egl.Surface, context);
+            // trying to make the EglContext current on a non-EGL window will do,
-            this.window = egl;
+            // nothing (the EglContext will remain current on the previous EGL window
+            // or the window it was constructed on (which may not be EGL)).
+            if (window is EglWindowInfo)
+                WindowInfo = (EglWindowInfo)window;
+            Egl.MakeCurrent(WindowInfo.Display, WindowInfo.Surface, WindowInfo.Surface, context);
         }
 
         public bool IsCurrent
@@ -100,10 +114,10 @@ namespace OpenTK.Platform.Egl
             }
             set
             {
-                if (Egl.SwapInterval(window.Display, value ? 1 : 0))
+                if (Egl.SwapInterval(WindowInfo.Display, value ? 1 : 0))
                     vsync = value;
                 else
-                    Debug.Print("[Warning] Egl.SwapInterval({0}, {1}) failed.", window.Display, value);
+                    Debug.Print("[Warning] Egl.SwapInterval({0}, {1}) failed.", WindowInfo.Display, value);
             }
         }
 
@@ -147,8 +161,8 @@ namespace OpenTK.Platform.Egl
             {
                 if (manual)
                 {
-                    Egl.MakeCurrent(window.Display, window.Surface, window.Surface, EGLContext.None);
+                    Egl.MakeCurrent(WindowInfo.Display, WindowInfo.Surface, WindowInfo.Surface, EGLContext.None);
-                    Egl.DestroyContext(window.Display, context);
+                    Egl.DestroyContext(WindowInfo.Display, context);
                 }
                 else
                 {
@@ -164,5 +178,42 @@ namespace OpenTK.Platform.Egl
         }
 
         #endregion
+
+        #region IGraphicsContextInternal Members
+
+        public IGraphicsContext Implementation
+        {
+            get { return this; }
+        }
+
+        public void LoadAll()
+        {
+            // Todo: enable those
+            //OpenTK.Graphics.ES10.ES.LoadAll();
+            OpenTK.Graphics.ES11.GL.LoadAll();
+            //OpenTK.Graphics.ES20.ES.LoadAll();
+        }
+
+        public ContextHandle Context
+        {
+            get { return new ContextHandle(context.Handle.Value); }
+        }
+
+        public void RegisterForDisposal(IDisposable resource)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void DisposeResources()
+        {
+            throw new NotImplementedException();
+        }
+
+        public IntPtr GetAddress(string function)
+        {
+            return Egl.GetProcAddress(function);
+        }
+
+        #endregion
     }
 }

Source/OpenTK/Platform/MacOS/AglContext.cs

@@ -429,9 +429,26 @@ namespace OpenTK.Platform.MacOS
             throw new Exception("The method or operation is not implemented.");
         }
 
+        private const string Library = "libdl.dylib";
+
+        [DllImport(Library, EntryPoint = "NSIsSymbolNameDefined")]
+        private static extern bool NSIsSymbolNameDefined(string s);
+        [DllImport(Library, EntryPoint = "NSLookupAndBindSymbol")]
+        private static extern IntPtr NSLookupAndBindSymbol(string s);
+        [DllImport(Library, EntryPoint = "NSAddressOfSymbol")]
+        private static extern IntPtr NSAddressOfSymbol(IntPtr symbol);
+
         IntPtr IGraphicsContextInternal.GetAddress(string function)
         {
-            throw new Exception("The method or operation is not implemented.");
+            string fname = "_" + function;
+            if (!NSIsSymbolNameDefined(fname))
+                return IntPtr.Zero;
+
+            IntPtr symbol = NSLookupAndBindSymbol(fname);
+            if (symbol != IntPtr.Zero)
+                symbol = NSAddressOfSymbol(symbol);
+
+            return symbol;
         }
 
         #endregion

Source/OpenTK/Platform/Windows/WinGLContext.cs

@@ -314,15 +314,16 @@ namespace OpenTK.Platform.Windows
 
         void SetGraphicsModePFD(GraphicsMode mode, WinWindowInfo window)
         {
-            if (mode.Index == IntPtr.Zero) throw new ArgumentException(
+            if (!mode.Index.HasValue)
-                "mode", "The Index (pixel format) of the GraphicsMode is not set.");
+                throw new GraphicsModeException("Invalid or unsupported GraphicsMode.");
+
             if (window == null) throw new ArgumentNullException("window", "Must point to a valid window.");
 
             PixelFormatDescriptor pfd = new PixelFormatDescriptor();
-            Functions.DescribePixelFormat(window.DeviceContext, (int)mode.Index,
+            Functions.DescribePixelFormat(window.DeviceContext, (int)mode.Index.Value,
                 API.PixelFormatDescriptorSize, ref pfd);
             Debug.WriteLine(mode.Index.ToString());
-            if (!Functions.SetPixelFormat(window.DeviceContext, (int)mode.Index, ref pfd))
+            if (!Functions.SetPixelFormat(window.DeviceContext, (int)mode.Index.Value, ref pfd))
                 throw new GraphicsContextException(String.Format(
                     "Requested GraphicsMode not available. SetPixelFormat error: {0}", Marshal.GetLastWin32Error()));
         }

Source/OpenTK/Platform/X11/X11GLControl.cs

@@ -24,13 +24,16 @@ namespace OpenTK.Platform.X11
 
         internal X11GLControl(GraphicsMode mode, Control control)
         {
+            if (!mode.Index.HasValue)
+                throw new GraphicsModeException("Invalid GraphicsMode.");
+
             this.mode = mode;
             this.control = control;
 
             X11WindowInfo window = (X11WindowInfo)this.WindowInfo;
-
             XVisualInfo info = new XVisualInfo();
-            info.VisualID = mode.Index;
+            
+            info.VisualID = mode.Index.Value;
             int dummy;
             window.VisualInfo = (XVisualInfo)Marshal.PtrToStructure(
                 Functions.XGetVisualInfo(window.Display, XVisualInfoMask.ID, ref info, out dummy), typeof(XVisualInfo));

Source/OpenTK/Platform/X11/X11GLNative.cs

@@ -124,7 +124,10 @@ namespace OpenTK.Platform.X11
             
             lock (API.Lock)
             {
-                info.VisualID = mode.Index;
+                if (!mode.Index.HasValue)
+                    throw new GraphicsModeException("Invalid or unsupported GraphicsMode.");
+
+                info.VisualID = mode.Index.Value;
                 int dummy;
                 window.VisualInfo = (XVisualInfo)Marshal.PtrToStructure(
                     Functions.XGetVisualInfo(window.Display, XVisualInfoMask.ID, ref info, out dummy), typeof(XVisualInfo));