private void DestroyContext()
{
if (Handle != ContextHandle.Zero)
{
try
{
// This will fail if the user calls Dispose() on thread X when the context is current on thread Y.
if (!Wgl.DeleteContext(Handle.Handle))
{
Debug.Print("Failed to destroy OpenGL context {0}. Error: {1}",
Handle.ToString(), Marshal.GetLastWin32Error());
}
}
catch (AccessViolationException e)
{
Debug.WriteLine("An access violation occured while destroying the OpenGL context. Please report at https://github.com/opentk/opentk/issues");
Debug.Indent();
Debug.Print("Marshal.GetLastWin32Error(): {0}", Marshal.GetLastWin32Error().ToString());
Debug.WriteLine(e.ToString());
Debug.Unindent();
}
Handle = ContextHandle.Zero;
}
}
public WinGLContext(GraphicsMode format, WinWindowInfo window, IGraphicsContext sharedContext,
int major, int minor, GraphicsContextFlags flags)
{
// There are many ways this code can break when accessed by multiple threads. The biggest offender is
// the sharedContext stuff, which will only become valid *after* this constructor returns.
// The easiest solution is to serialize all context construction - hence the big lock, below.
lock (LoadLock)
{
if (window == null)
{
throw new ArgumentNullException("window", "Must point to a valid window.");
}
if (window.Handle == IntPtr.Zero)
{
throw new ArgumentException("window", "Must be a valid window.");
}
IntPtr current_context = Wgl.GetCurrentContext();
INativeWindow temp_window = null;
TemporaryContext temp_context = null;
try
{
if (current_context == IntPtr.Zero)
{
// Create temporary context to load WGL extensions
temp_window = new NativeWindow();
temp_context = new TemporaryContext(temp_window);
current_context = Wgl.GetCurrentContext();
if (current_context != IntPtr.Zero && current_context == temp_context.Context.Handle)
{
new Wgl().LoadEntryPoints();
}
}
Debug.Print("OpenGL will be bound to window:{0} on thread:{1}", window.Handle,
System.Threading.Thread.CurrentThread.ManagedThreadId);
ModeSelector = new WinGraphicsMode(window.DeviceContext);
Mode = SetGraphicsModePFD(ModeSelector, format, (WinWindowInfo)window);
if (Wgl.SupportsFunction("wglCreateContextAttribsARB"))
{
try
{
Debug.Write("Using WGL_ARB_create_context... ");
List <int> attributes = new List <int>();
attributes.Add((int)ArbCreateContext.MajorVersion);
attributes.Add(major);
attributes.Add((int)ArbCreateContext.MinorVersion);
attributes.Add(minor);
if (flags != 0)
{
attributes.Add((int)ArbCreateContext.ContextFlags);
attributes.Add((int)GetARBContextFlags(flags));
attributes.Add((int)ArbCreateContext.ProfileMask);
attributes.Add((int)GetARBContextProfile(flags));
}
// According to the docs, " <attribList> specifies a list of attributes for the context.
// The list consists of a sequence of <name,value> pairs terminated by the
// value 0. [...]"
// Is this a single 0, or a <0, 0> pair? (Defensive coding: add two zeroes just in case).
attributes.Add(0);
attributes.Add(0);
Handle = new ContextHandle(
Wgl.Arb.CreateContextAttribs(
window.DeviceContext,
sharedContext != null ? (sharedContext as IGraphicsContextInternal).Context.Handle : IntPtr.Zero,
attributes.ToArray()));
if (Handle == ContextHandle.Zero)
{
Debug.Print("failed. (Error: {0})", Marshal.GetLastWin32Error());
}
}
catch (Exception e) { Debug.Print(e.ToString()); }
}
if (Handle == ContextHandle.Zero)
{
// Failed to create GL3-level context, fall back to GL2.
Debug.Write("Falling back to GL2... ");
Handle = new ContextHandle(Wgl.CreateContext(window.DeviceContext));
if (Handle == ContextHandle.Zero)
{
Handle = new ContextHandle(Wgl.CreateContext(window.DeviceContext));
}
if (Handle == ContextHandle.Zero)
{
throw new GraphicsContextException(
String.Format("Context creation failed. Wgl.CreateContext() error: {0}.",
Marshal.GetLastWin32Error()));
}
}
Debug.WriteLine(String.Format("success! (id: {0})", Handle));
}
finally
{
if (temp_context != null)
{
temp_context.Dispose();
temp_context = null;
}
if (temp_window != null)
{
temp_window.Dispose();
temp_window = null;
}
}
}
// Todo: is this comment still true?
// On intel drivers, wgl entry points appear to change
// when creating multiple contexts. As a workaround,
// we reload Wgl entry points every time we create a
// new context - this solves the issue without any apparent
// side-effects (i.e. the old contexts can still be handled
// using the new entry points.)
// Sigh...
MakeCurrent(window);
new Wgl().LoadEntryPoints();
if (sharedContext != null)
{
Marshal.GetLastWin32Error();
Debug.Write(String.Format("Sharing state with context {0}: ", sharedContext));
bool result = Wgl.ShareLists((sharedContext as IGraphicsContextInternal).Context.Handle, Handle.Handle);
Debug.WriteLine(result ? "success!" : "failed with win32 error " + Marshal.GetLastWin32Error());
}
}
// Queries pixel formats through the WGL_ARB_pixel_format extension
// This method only returns accelerated formats. If no format offers
// hardware acceleration (e.g. we are running in a VM or in a remote desktop
// connection), this method will return 0 formats and we will fall back to
// ChoosePixelFormatPFD.
private GraphicsMode ChoosePixelFormatARB(IntPtr device, GraphicsMode desired_mode)
{
GraphicsMode created_mode = null;
GraphicsMode mode = new GraphicsMode(desired_mode);
if (Wgl.SupportsExtension("WGL_ARB_pixel_format") &&
Wgl.SupportsFunction("wglChoosePixelFormatARB"))
{
int[] format = new int[1];
int count;
List <int> attributes = new List <int>();
bool retry = false;
do
{
attributes.Clear();
attributes.Add((int)WGL_ARB_pixel_format.AccelerationArb);
attributes.Add((int)WGL_ARB_pixel_format.FullAccelerationArb);
attributes.Add((int)WGL_ARB_pixel_format.DrawToWindowArb);
attributes.Add(1);
if (mode.ColorFormat.Red > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.RedBitsArb);
attributes.Add(mode.ColorFormat.Red);
}
if (mode.ColorFormat.Green > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.GreenBitsArb);
attributes.Add(mode.ColorFormat.Green);
}
if (mode.ColorFormat.Blue > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.BlueBitsArb);
attributes.Add(mode.ColorFormat.Blue);
}
if (mode.ColorFormat.Alpha > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.AlphaBitsArb);
attributes.Add(mode.ColorFormat.Alpha);
}
if (mode.Depth > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.DepthBitsArb);
attributes.Add(mode.Depth);
}
if (mode.Stencil > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.StencilBitsArb);
attributes.Add(mode.Stencil);
}
if (mode.AccumulatorFormat.Red > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.AccumRedBitsArb);
attributes.Add(mode.AccumulatorFormat.Red);
}
if (mode.AccumulatorFormat.Green > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.AccumGreenBitsArb);
attributes.Add(mode.AccumulatorFormat.Green);
}
if (mode.AccumulatorFormat.Blue > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.AccumBlueBitsArb);
attributes.Add(mode.AccumulatorFormat.Blue);
}
if (mode.AccumulatorFormat.Alpha > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.AccumAlphaBitsArb);
attributes.Add(mode.AccumulatorFormat.Alpha);
}
if (mode.Samples > 0 &&
Wgl.SupportsExtension("WGL_ARB_multisample"))
{
attributes.Add((int)WGL_ARB_multisample.SampleBuffersArb);
attributes.Add(1);
attributes.Add((int)WGL_ARB_multisample.SamplesArb);
attributes.Add(mode.Samples);
}
if (mode.Buffers > 0)
{
attributes.Add((int)WGL_ARB_pixel_format.DoubleBufferArb);
attributes.Add(mode.Buffers > 1 ? 1 : 0);
}
if (mode.Stereo)
{
attributes.Add((int)WGL_ARB_pixel_format.StereoArb);
attributes.Add(1);
}
attributes.Add(0);
attributes.Add(0);
if (Wgl.Arb.ChoosePixelFormat(device, attributes.ToArray(), null, format.Length, format, out count) &&
count > 0)
{
created_mode = DescribePixelFormatARB(device, format[0]);
retry = false;
}
else
{
Debug.Print("[WGL] ChoosePixelFormatARB failed with {0}", Marshal.GetLastWin32Error());
retry = Utilities.RelaxGraphicsMode(ref mode);
}
}while (retry);
}
else
{
Debug.WriteLine("[WGL] ChoosePixelFormatARB not supported on this context");
}
return(created_mode);
}
public static bool SupportsExtension(string name)
{
return(SupportsExtension(Wgl.GetCurrentDC(), name));
}
private GraphicsMode DescribePixelFormatARB(IntPtr device, int pixelformat)
{
GraphicsMode created_mode = null;
// See http://www.opengl.org/registry/specs/ARB/wgl_pixel_format.txt for more details
if (Wgl.SupportsFunction("wglGetPixelFormatAttribivARB"))
{
// Define the list of attributes we are interested in.
// The results will be stored in the 'values' array below.
int[] attribs = new int[]
{
(int)WGL_ARB_pixel_format.AccelerationArb,
(int)WGL_ARB_pixel_format.RedBitsArb,
(int)WGL_ARB_pixel_format.GreenBitsArb,
(int)WGL_ARB_pixel_format.BlueBitsArb,
(int)WGL_ARB_pixel_format.AlphaBitsArb,
(int)WGL_ARB_pixel_format.ColorBitsArb,
(int)WGL_ARB_pixel_format.DepthBitsArb,
(int)WGL_ARB_pixel_format.StencilBitsArb,
(int)WGL_ARB_multisample.SampleBuffersArb,
(int)WGL_ARB_multisample.SamplesArb,
(int)WGL_ARB_pixel_format.AccumRedBitsArb,
(int)WGL_ARB_pixel_format.AccumGreenBitsArb,
(int)WGL_ARB_pixel_format.AccumBlueBitsArb,
(int)WGL_ARB_pixel_format.AccumAlphaBitsArb,
(int)WGL_ARB_pixel_format.AccumBitsArb,
(int)WGL_ARB_pixel_format.DoubleBufferArb,
(int)WGL_ARB_pixel_format.StereoArb,
0
};
// Allocate storage for the results of GetPixelFormatAttrib queries
int[] values = new int[attribs.Length];
// Get the format attributes for this pixel format
if (!Wgl.Arb.GetPixelFormatAttrib(device, pixelformat, 0, attribs.Length - 1, attribs, values))
{
Debug.Print("[Warning] Failed to detect attributes for PixelFormat: {0}.", pixelformat);
}
// Skip formats that don't offer full hardware acceleration
WGL_ARB_pixel_format acceleration = (WGL_ARB_pixel_format)values[0];
if (acceleration == WGL_ARB_pixel_format.FullAccelerationArb)
{
// Construct a new GraphicsMode to describe this format
created_mode = new GraphicsMode(new IntPtr(pixelformat),
new ColorFormat(values[1], values[2], values[3], values[4]),
values[6],
values[7],
values[8] != 0 ? values[9] : 0,
new ColorFormat(values[10], values[11], values[12], values[13]),
values[15] == 1 ? 2 : 1,
values[16] == 1 ? true : false);
}
}
return(created_mode);
}
