From d9afed2d1069fcf0dd6ece449e8d5de194f3ce4a Mon Sep 17 00:00:00 2001
From: "Stefanos A." <stapostol@gmail.com>
Date: Sat, 16 Nov 2013 22:38:17 +0100
Subject: [PATCH] Setup correct class style for OpenGL

On Windows, we need to have a CS_OWNDC class style on windows with
OpenGL contexts attached. In Windows.Forms, we can set this via the
Control.CreateParams property. See
https://www.opengl.org/wiki/Creating_an_OpenGL_Context_(WGL)
---
 Source/GLControl/GLControl.cs | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/Source/GLControl/GLControl.cs b/Source/GLControl/GLControl.cs
index 9e9619a9..b648a5e6 100644
--- a/Source/GLControl/GLControl.cs
+++ b/Source/GLControl/GLControl.cs
@@ -155,6 +155,30 @@ namespace OpenTK
 
         #region --- Protected Methods ---
 
+        /// <summary>
+        /// Gets the <c>CreateParams</c> instance for this <c>GLControl</c>
+        /// </summary>
+        protected override CreateParams CreateParams
+        {
+            get
+            {
+                const int CS_VREDRAW = 0x1;
+                const int CS_HREDRAW = 0x2;
+                const int CS_OWNDC = 0x20;
+                const int WS_CLIPCHILDREN = 0x02000000;
+                const int WS_CLIPSIBLINGS = 0x04000000;
+
+                CreateParams cp = base.CreateParams;
+                if (Configuration.RunningOnWindows)
+                {
+                    // Setup necessary class style for OpenGL on windows
+                    cp.ClassStyle |= CS_VREDRAW | CS_HREDRAW | CS_OWNDC;
+                    cp.Style |= WS_CLIPCHILDREN | WS_CLIPSIBLINGS;
+                }
+                return cp;
+            }
+        }
+
         /// <summary>Raises the HandleCreated event.</summary>
         /// <param name="e">Not used.</param>
         protected override void OnHandleCreated(EventArgs e)
-- 
2.34.1