/GoliatEditor/OpenTK/1.1/Source/OpenTK/Platform/Windows/WinGLContext.cs
C# | 509 lines | 376 code | 82 blank | 51 comment | 67 complexity | 2aa6b5bd4dc08fad9e6180b155ea72a9 MD5 | raw file
- #region --- License ---
- /* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
- * Contributions from Erik Ylvisaker
- * See license.txt for license info
- */
- #endregion
- #region --- Using Directives ---
- using System;
- using System.Collections.Generic;
- using System.Text;
- using System.Runtime.InteropServices;
- using System.Diagnostics;
- using OpenTK.Graphics;
- using OpenTK.Graphics.OpenGL;
- #endregion
- namespace OpenTK.Platform.Windows
- {
- /// \internal
- /// <summary>
- /// Provides methods to create and control an opengl context on the Windows platform.
- /// This class supports OpenTK, and is not intended for use by OpenTK programs.
- /// </summary>
- internal sealed class WinGLContext : DesktopGraphicsContext
- {
- static readonly object LoadLock = new object();
- IntPtr device_context;
- bool vsync_supported;
- bool vsync_tear_supported;
- readonly WinGraphicsMode ModeSelector;
- // We need to create a temp context in order to load
- // wgl extensions (e.g. for multisampling or GL3).
- // We cannot rely on any WGL extensions before
- // we load them with the temporary context.
- class TemporaryContext : IDisposable
- {
- public ContextHandle Context;
- public TemporaryContext(INativeWindow native)
- {
- Debug.WriteLine("[WGL] Creating temporary context to load extensions");
- if (native == null)
- throw new ArgumentNullException();
- // Create temporary context and load WGL entry points
- // First, set a compatible pixel format to the device context
- // of the temp window
- WinWindowInfo window = native.WindowInfo as WinWindowInfo;
- WinGraphicsMode selector = new WinGraphicsMode(window.DeviceContext);
- WinGLContext.SetGraphicsModePFD(selector, GraphicsMode.Default, window);
- bool success = false;
- // Then, construct a temporary context and load all wgl extensions
- Context = new ContextHandle(Wgl.CreateContext(window.DeviceContext));
- if (Context != ContextHandle.Zero)
- {
- // Make the context current.
- // Note: on some video cards and on some virtual machines, wglMakeCurrent
- // may fail with an errorcode of 6 (INVALID_HANDLE). The suggested workaround
- // is to call wglMakeCurrent in a loop until it succeeds.
- // See https://www.opengl.org/discussion_boards/showthread.php/171058-nVidia-wglMakeCurrent()-multiple-threads
- // Sigh...
- for (int retry = 0; retry < 5 && !success; retry++)
- {
- success = Wgl.MakeCurrent(window.DeviceContext, Context.Handle);
- if (!success)
- {
- Debug.Print("wglMakeCurrent failed with error: {0}. Retrying", Marshal.GetLastWin32Error());
- System.Threading.Thread.Sleep(10);
- }
- }
- }
- else
- {
- Debug.Print("[WGL] CreateContext failed with error: {0}", Marshal.GetLastWin32Error());
- }
- if (!success)
- {
- Debug.WriteLine("[WGL] Failed to create temporary context");
- }
- }
- public void Dispose()
- {
- if (Context != ContextHandle.Zero)
- {
- Wgl.MakeCurrent(IntPtr.Zero, IntPtr.Zero);
- Wgl.DeleteContext(Context.Handle);
- }
- }
- }
- #region --- Contructors ---
- 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());
- }
- }
- static ArbCreateContext GetARBContextFlags(GraphicsContextFlags flags)
- {
- ArbCreateContext result = 0;
- result |= (flags & GraphicsContextFlags.ForwardCompatible) != 0 ?
- ArbCreateContext.CoreProfileBit : ArbCreateContext.CompatibilityProfileBit;
- return result;
- }
- static ArbCreateContext GetARBContextProfile(GraphicsContextFlags flags)
- {
- ArbCreateContext result = 0;
- result |= (flags & GraphicsContextFlags.Debug) != 0 ? ArbCreateContext.DebugBit : 0;
- return result;
- }
- public WinGLContext(ContextHandle handle, WinWindowInfo window, IGraphicsContext sharedContext,
- int major, int minor, GraphicsContextFlags flags)
- {
- if (handle == ContextHandle.Zero)
- throw new ArgumentException("handle");
- if (window == null)
- throw new ArgumentNullException("window");
- Handle = handle;
- }
- #endregion
- #region IGraphicsContext Members
- #region SwapBuffers
- public override void SwapBuffers()
- {
- if (!Functions.SwapBuffers(DeviceContext))
- throw new GraphicsContextException(String.Format(
- "Failed to swap buffers for context {0} current. Error: {1}", this, Marshal.GetLastWin32Error()));
- }
- #endregion
- #region MakeCurrent
- public override void MakeCurrent(IWindowInfo window)
- {
- lock (LoadLock)
- {
- bool success;
- WinWindowInfo wnd = window as WinWindowInfo;
- if (wnd != null)
- {
- if (wnd.Handle == IntPtr.Zero)
- throw new ArgumentException("window", "Must point to a valid window.");
- success = Wgl.MakeCurrent(wnd.DeviceContext, Handle.Handle);
- device_context = wnd.DeviceContext;
- }
- else
- {
- success = Wgl.MakeCurrent(IntPtr.Zero, IntPtr.Zero);
- device_context = IntPtr.Zero;
- }
- if (!success)
- {
- throw new GraphicsContextException(String.Format(
- "Failed to make context {0} current. Error: {1}", this, Marshal.GetLastWin32Error()));
- }
- }
- }
- #endregion
- #region IsCurrent
- public override bool IsCurrent
- {
- get { return Wgl.GetCurrentContext() == Handle.Handle; }
- }
- #endregion
- #region SwapInterval
- public override int SwapInterval
- {
- get
- {
- lock (LoadLock)
- {
- if (vsync_supported)
- return Wgl.Ext.GetSwapInterval();
- else
- return 0;
- }
- }
- set
- {
- lock (LoadLock)
- {
- if (vsync_supported)
- {
- if (value < 0 && !vsync_tear_supported)
- {
- value = 1;
- }
- if (!Wgl.Ext.SwapInterval(value))
- {
- Debug.Print("wglSwapIntervalEXT call failed.");
- }
- }
- }
- }
- }
- #endregion
- #region void LoadAll()
- public override void LoadAll()
- {
- lock (LoadLock)
- {
- new Wgl().LoadEntryPoints();
- vsync_supported =
- Wgl.SupportsExtension(DeviceContext, "WGL_EXT_swap_control") &&
- Wgl.SupportsFunction("wglGetSwapIntervalEXT") &&
- Wgl.SupportsFunction("wglSwapIntervalEXT");
- vsync_tear_supported =
- Wgl.SupportsExtension(DeviceContext, "WGL_EXT_swap_control_tear");
- }
- base.LoadAll();
- }
- #endregion
- #endregion
- #region IGLContextInternal Members
- #region IWindowInfo IGLContextInternal.Info
- /*
- IWindowInfo IGraphicsContextInternal.Info
- {
- get { return (IWindowInfo)windowInfo; }
- }
- */
- #endregion
- #region GetAddress
- public override IntPtr GetAddress(IntPtr function_string)
- {
- IntPtr address = Wgl.GetProcAddress(function_string);
- if (!IsValid(address))
- {
- address = Functions.GetProcAddress(WinFactory.OpenGLHandle, function_string);
- }
- return address;
- }
- static bool IsValid(IntPtr address)
- {
- // See https://www.opengl.org/wiki/Load_OpenGL_Functions
- long a = address.ToInt64();
- bool is_valid = (a < -1) || (a > 3);
- return is_valid;
- }
- #endregion
- #endregion
- #region Internal Methods
- #region SetGraphicsModePFD
- // Note: there is no relevant ARB function.
- internal static GraphicsMode SetGraphicsModePFD(WinGraphicsMode mode_selector,
- GraphicsMode mode, WinWindowInfo window)
- {
- Debug.Write("Setting pixel format... ");
- if (window == null)
- throw new ArgumentNullException("window", "Must point to a valid window.");
- if (!mode.Index.HasValue)
- {
- mode = mode_selector.SelectGraphicsMode(
- mode.ColorFormat, mode.Depth, mode.Stencil,
- mode.Samples, mode.AccumulatorFormat,
- mode.Buffers, mode.Stereo);
- }
- PixelFormatDescriptor pfd = new PixelFormatDescriptor();
- Functions.DescribePixelFormat(
- window.DeviceContext, (int)mode.Index.Value,
- API.PixelFormatDescriptorSize, ref pfd);
- Debug.WriteLine(mode.Index.ToString());
- if (!Functions.SetPixelFormat(window.DeviceContext, (int)mode.Index.Value, ref pfd))
- {
- throw new GraphicsContextException(String.Format(
- "Requested GraphicsMode not available. SetPixelFormat error: {0}",
- Marshal.GetLastWin32Error()));
- }
- return mode;
- }
- #endregion
- #region internal IntPtr DeviceContext
- internal IntPtr DeviceContext
- {
- get
- {
- return device_context;
- }
- }
- #endregion
- #endregion
- #region Overrides
- /// <summary>Returns a System.String describing this OpenGL context.</summary>
- /// <returns>A System.String describing this OpenGL context.</returns>
- public override string ToString()
- {
- return (this as IGraphicsContextInternal).Context.ToString();
- }
- #endregion
- #region IDisposable Members
- protected override void Dispose(bool calledManually)
- {
- if (!IsDisposed)
- {
- if (calledManually)
- {
- DestroyContext();
- }
- IsDisposed = true;
- }
- }
- #region private void DestroyContext()
- 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 http://www.opentk.com.");
- Debug.Indent();
- Debug.Print("Marshal.GetLastWin32Error(): {0}", Marshal.GetLastWin32Error().ToString());
- Debug.WriteLine(e.ToString());
- Debug.Unindent();
- }
- Handle = ContextHandle.Zero;
- }
- }
- #endregion
- #endregion
- }
- }