'OpenTK.Platform.Windows.Wgl' is not accessible in this context because it is 'Friend'.

Imports OpenTK.Graphics.OpenGL
Imports OpenTK.Platform.Windows
Imports System
 
Module OpenGL
 
    Public Declare Sub ZeroMemory Lib "kernel32.dll" Alias "RtlZeroMemory" (ByVal Destination As Gdi.PIXELFORMATDESCRIPTOR, ByVal Length As Integer)
 
    Dim hRC As System.IntPtr
 
    Public Sub EnableOpenGL(ByVal ghDC As System.IntPtr)
        Dim pfd As PixelFormatDescriptor
        Dim PixelFormat As Integer
 
        ZeroMemory(pfd, Len(pfd))
        pfd.Size = Len(pfd)
        pfd.Version = 1
        pfd.Flags = PFD_DRAW_TO_WINDOW Or PFD_SUPPORT_OPENGL Or PFD_DOUBLEBUFFER
        pfd.PixelType = PFD_TYPE_RGBA
        pfd.ColorBits = 32
        pfd.DepthBits = 32
        pfd.StencilBits = 32
        pfd.LayerType = Gdi.PFD_MAIN_PLANE
 
        PixelFormat = Gdi.ChoosePixelFormat(ghDC, pfd)
 
        If PixelFormat = 0 Then
            MsgBox("Unable to retrieve pixel format")
            End
        End If
        If Not (Gdi.SetPixelFormat(ghDC, PixelFormat, pfd)) Then
            MsgBox("Unable to set pixel format")
            End
        End If
        hRC = Wgl.wglCreateContext(ghDC)
        If hRC.ToInt32 = 0 Then
            MsgBox("Unable to get rendering context")
            End
        End If
        If Not (Wgl.wglMakeCurrent(ghDC, hRC)) Then
            MsgBox("Unable to make rendering context current")
            End
        End If
 
    End Sub
 
    Sub DisableOpenGL()
        Wgl.wglMakeCurrent(IntPtr.Zero, IntPtr.Zero)
        Wgl.wglDeleteContext(hRC)
    End Sub
 
End Module