Delay VisualInfo construction (fixes #17)

In OpenTK 1.1, GraphicsMode queries the platform for a mode id lazily. By delaying VisualInfo selection until the GraphicsContext is constructed we ensure that a concrete GraphicsMode is selected and ready for use.
opentk · Dec 14, 2013 · 61f334f · 61f334f
1 parent 19d9beb
commit 61f334f
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Showing 2 changed files with 20 additions and 12 deletions.
diff --git a/Source/GLControl/X11GLControl.cs b/Source/GLControl/X11GLControl.cs
@@ -63,6 +63,10 @@ public override string ToString()
         GraphicsMode mode;
         IWindowInfo window_info;
         IntPtr display;
+        IntPtr rootWindow;
+
+        // Use reflection to retrieve the necessary values from Mono's Windows.Forms implementation.
+        Type xplatui = Type.GetType("System.Windows.Forms.XplatUIX11, System.Windows.Forms");
 
         #endregion
 
@@ -77,16 +81,24 @@ internal X11GLControl(GraphicsMode mode, Control control)
 
             this.mode = mode;
 
-            // Use reflection to retrieve the necessary values from Mono's Windows.Forms implementation.
-            Type xplatui = Type.GetType("System.Windows.Forms.XplatUIX11, System.Windows.Forms");
             if (xplatui == null) throw new PlatformNotSupportedException(
                     "System.Windows.Forms.XplatUIX11 missing. Unsupported platform or Mono runtime version, aborting.");
 
             // get the required handles from the X11 API.
             display = (IntPtr)GetStaticFieldValue(xplatui, "DisplayHandle");
-            IntPtr rootWindow = (IntPtr)GetStaticFieldValue(xplatui, "RootWindow");
+            rootWindow = (IntPtr)GetStaticFieldValue(xplatui, "RootWindow");
             int screen = (int)GetStaticFieldValue(xplatui, "ScreenNo");
 
+            window_info = Utilities.CreateX11WindowInfo(display, screen, control.Handle, rootWindow, IntPtr.Zero);
+        }
+
+        #region IGLControl Members
+
+        public IGraphicsContext CreateContext(int major, int minor, GraphicsContextFlags flags)
+        {
+            GraphicsContext context =  new GraphicsContext(mode, this.WindowInfo, major, minor, flags);
+            mode = context.GraphicsMode;
+
             // get the XVisualInfo for this GraphicsMode
             XVisualInfo info = new XVisualInfo();
             info.VisualID = mode.Index.Value;
@@ -98,14 +110,7 @@ internal X11GLControl(GraphicsMode mode, Control control)
             SetStaticFieldValue(xplatui, "CustomVisual", info.Visual);
             SetStaticFieldValue(xplatui, "CustomColormap", XCreateColormap(display, rootWindow, info.Visual, 0));
 
-            window_info = Utilities.CreateX11WindowInfo(display, screen, control.Handle, rootWindow, infoPtr);
-        }
-
-        #region IGLControl Members
-
-        public IGraphicsContext CreateContext(int major, int minor, GraphicsContextFlags flags)
-        {
-            return new GraphicsContext(mode, this.WindowInfo, major, minor, flags);
+            return context;
         }
 
         public bool IsIdle

diff --git a/Source/OpenTK/Platform/Utilities.cs b/Source/OpenTK/Platform/Utilities.cs
@@ -212,7 +212,10 @@ public static IWindowInfo CreateX11WindowInfo(IntPtr display, int screen, IntPtr
             window.Screen = screen;
             window.Handle = windowHandle;
             window.RootWindow = rootWindow;
-            window.VisualInfo = (X11.XVisualInfo)Marshal.PtrToStructure(visualInfo, typeof(X11.XVisualInfo));
+            if (visualInfo != IntPtr.Zero)
+            {
+                window.VisualInfo = (X11.XVisualInfo)Marshal.PtrToStructure(visualInfo, typeof(X11.XVisualInfo));
+            }
 
             return window;
         }