GLWidgetOpenTK.cs

using System;
using System.Runtime.InteropServices;
using Gtk;
using OpenToolkit.Graphics.OpenGL4;

//this is just a template, if you encounter incorrect drawing when resizing  you can disable double buffering on the top level window for the widget, I couldn't find a better fix
//and will work only on Linux, to fix that you could change the bindings context that will be loaded with one that workd on another platforms like glfw
namespace OpenToolkit
{
	public class GLWidget : GLArea
	{
		private static bool _bindingsLoaded;
		public GLWidget() { }
		public GLWidget(GLArea area) : base(area.Handle) { }
		public GLWidget(IntPtr handle) : base(handle) { }
		
		protected override void OnRealized()
		{
			base.OnRealized();
			MakeCurrent();
			if (!_bindingsLoaded)
			{
				GL.LoadBindings(new GLXBindingsContext());
			}
		}

		protected override void OnResize(int width, int height)
		{
			base.OnResize(width, height);
			QueueRender();
		}
	}

	public class GLXBindingsContext : IBindingsContext
	{
		public IntPtr GetProcAddress(string procName)
		{
			return glXGetProcAddress(procName);
		}

		[DllImport("libGL", CharSet = CharSet.Ansi)]
		private static extern IntPtr glXGetProcAddress(string procName);
	}
}