[X11] Improved vsync support

OpenTK will now check for GLX_EXT_swap_control, GLX_MESA_swap_control
and GLX_SGI_swap_control. This allows us to control vsync on more
systems.

diff --git a/Source/OpenTK/Platform/X11/Bindings/Glx.cs b/Source/OpenTK/Platform/X11/Bindings/Glx.cs
index 4a312b9..27c8369 100644 (file)
--- a/Source/OpenTK/Platform/X11/Bindings/Glx.cs
+++ b/Source/OpenTK/Platform/X11/Bindings/Glx.cs
@@ -266,7 +266,14 @@ namespace OpenTK.Platform.X11
         static string[] EntryPointNames = new string[]
         {
             "glXCreateContextAttribs",
+            "glXSwapIntervalEXT",
+            "glXGetSwapIntervalEXT",
+            "glXSwapIntervalMESA",
+            "glXGetSwapIntervalMESA",
+            "glXSwapIntervalOML",
+            "glXGetSwapIntervalOML",
             "glXSwapIntervalSGI",
+            "glXGetSwapIntervalSGI",
         };
         static IntPtr[] EntryPoints = new IntPtr[EntryPointNames.Length];
 
@@ -405,6 +412,36 @@ namespace OpenTK.Platform.X11
             #endregion
         }
 
+        public partial class Ext
+        {
+            [AutoGenerated(EntryPoint = "glXSwapIntervalEXT")]
+            public static ErrorCode SwapInterval(int interval)
+            {
+                throw new NotImplementedException();
+            }
+
+            [AutoGenerated(EntryPoint = "glXGetSwapIntervalEXT")]
+            public static int GetSwapInterval()
+            {
+                throw new NotImplementedException();
+            }
+        }
+
+        public partial class Mesa
+        {
+            [AutoGenerated(EntryPoint = "glXSwapIntervalMESA")]
+            public static ErrorCode SwapInterval(int interval)
+            {
+                throw new NotImplementedException();
+            }
+
+            [AutoGenerated(EntryPoint = "glXGetSwapIntervalMESA")]
+            public static int GetSwapInterval()
+            {
+                throw new NotImplementedException();
+            }
+        }
+
         public partial class Sgi
         {
             [AutoGenerated(EntryPoint = "glXSwapIntervalSGI")]
@@ -412,6 +449,12 @@ namespace OpenTK.Platform.X11
             {
                 throw new NotImplementedException();
             }
+
+            [AutoGenerated(EntryPoint = "glXGetSwapIntervalSGI")]
+            public static int GetSwapInterval()
+            {
+                throw new NotImplementedException();
+            }
         }
 
         [Slot(0)]
@@ -419,7 +462,22 @@ namespace OpenTK.Platform.X11
         internal unsafe static extern IntPtr glXCreateContextAttribsARB(IntPtr display, IntPtr fbconfig, IntPtr share_context, bool direct, int* attribs);
         [Slot(1)]
         [DllImport(Library, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
-        internal static extern IntPtr glXSwapIntervalSGI(int interval);
+        internal static extern ErrorCode glXSwapIntervalEXT(int interval);
+        [Slot(2)]
+        [DllImport(Library, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
+        internal static extern int glXGetSwapIntervalEXT();
+        [Slot(3)]
+        [DllImport(Library, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
+        internal static extern ErrorCode glXSwapIntervalMESA(int interval);
+        [Slot(4)]
+        [DllImport(Library, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
+        internal static extern int glXGetSwapIntervalMESA();
+        [Slot(5)]
+        [DllImport(Library, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
+        internal static extern ErrorCode glXSwapIntervalSGI(int interval);
+        [Slot(6)]
+        [DllImport(Library, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
+        internal static extern int glXGetSwapIntervalSGI();
 
         #endregion
     }

diff --git a/Source/OpenTK/Platform/X11/X11GLContext.cs b/Source/OpenTK/Platform/X11/X11GLContext.cs
index e67c151..9596f0e 100644 (file)
--- a/Source/OpenTK/Platform/X11/X11GLContext.cs
+++ b/Source/OpenTK/Platform/X11/X11GLContext.cs
@@ -29,10 +29,13 @@ namespace OpenTK.Platform.X11
         // current on window originating from a different display.
         IntPtr display;
         X11WindowInfo currentWindow;
-        bool vsync_supported;
+        bool vsync_ext_supported;
+        bool vsync_mesa_supported;
+        bool vsync_sgi_supported;
         bool vsync_tear_supported;
-        int swap_interval = 1; // As defined in GLX_SGI_swap_control
+        int sgi_swap_interval = 1; // As defined in GLX_SGI_swap_control
         readonly X11GraphicsMode ModeSelector = new X11GraphicsMode();
+        string extensions = null;
 
         #endregion
 
@@ -232,7 +235,7 @@ namespace OpenTK.Platform.X11
             return result;
         }
 
-        static bool SupportsExtension(IntPtr display, X11WindowInfo window, string e)
+        bool SupportsExtension(IntPtr display, X11WindowInfo window, string e)
         {
             if (window == null)
                 throw new ArgumentNullException("window");
@@ -241,15 +244,17 @@ namespace OpenTK.Platform.X11
             if (window.Display != display)
                 throw new InvalidOperationException();
 
-            string extensions = null;
-            using (new XLock(display))
+            if (String.IsNullOrEmpty(extensions))
             {
-                extensions = Glx.QueryExtensionsString(display, window.Screen);
+                using (new XLock(display))
+                {
+                    extensions = Glx.QueryExtensionsString(display, window.Screen);
+                }
             }
             return !String.IsNullOrEmpty(extensions) && extensions.Contains(e);
         }
 
-        static bool SupportsCreateContextAttribs(IntPtr display, X11WindowInfo window)
+        bool SupportsCreateContextAttribs(IntPtr display, X11WindowInfo window)
         {
             return
                 SupportsExtension(display, window, "GLX_ARB_create_context") &&
@@ -354,29 +359,40 @@ namespace OpenTK.Platform.X11
         {
             get
             {
-                if (vsync_supported)
-                    return swap_interval;
-                else
-                    return 0;
+                using (new XLock(display))
+                {
+                    if (vsync_ext_supported)
+                        return Glx.Ext.GetSwapInterval();
+                    else if (vsync_mesa_supported)
+                        return Glx.Mesa.GetSwapInterval();
+                    else if (vsync_sgi_supported)
+                        return sgi_swap_interval;
+                    else
+                        return 0;
+                }
             }
             set
             {
-                if (vsync_supported)
+                if (value < 0 && !vsync_tear_supported)
                 {
-                    if (value < 0 && !vsync_tear_supported)
-                    {
-                        value = 1;
-                    }
+                    value = 1;
+                }
 
-                    ErrorCode error_code = 0;
-                    using (new XLock(Display))
+                ErrorCode error_code = 0;
+                using (new XLock(Display))
+                {
+                    if (vsync_ext_supported)
+                        error_code = Glx.Ext.SwapInterval(value);
+                    else if (vsync_mesa_supported)
+                        error_code = Glx.Mesa.SwapInterval(value);
+                    else if (vsync_sgi_supported)
                         error_code = Glx.Sgi.SwapInterval(value);
-
-                    if (error_code == X11.ErrorCode.NO_ERROR)
-                        swap_interval = value;
-                    else
-                        Debug.Print("VSync = {0} failed, error code: {1}.", value, error_code);
                 }
+
+                if (error_code == X11.ErrorCode.NO_ERROR)
+                    sgi_swap_interval = value;
+                else
+                    Debug.Print("VSync = {0} failed, error code: {1}.", value, error_code);
             }
         }
 
@@ -386,12 +402,23 @@ namespace OpenTK.Platform.X11
 
         public override void LoadAll()
         {
-            vsync_supported =
+            vsync_ext_supported =
+                SupportsExtension(display, currentWindow, "GLX_EXT_swap_control") &&
+                Glx.SupportsFunction("glXSwapIntervalEXT") &&
+                Glx.SupportsFunction("glXGetSwapIntervalEXT");
+            vsync_mesa_supported =
+                SupportsExtension(display, currentWindow, "GLX_MESA_swap_control") &&
+                Glx.SupportsFunction("glXSwapIntervalMESA") &&
+                Glx.SupportsFunction("glXGetSwapIntervalMESA");
+            vsync_sgi_supported =
                 SupportsExtension(display, currentWindow, "GLX_SGI_swap_control") &&
                 Glx.SupportsFunction("glXSwapIntervalSGI");
+            Debug.Print("Context supports vsync: {0}.",
+                vsync_ext_supported || vsync_mesa_supported || vsync_ext_supported);
+
             vsync_tear_supported =
                 SupportsExtension(display, currentWindow, "GLX_EXT_swap_control_tear");
-            Debug.Print("Context supports vsync: {0}.", vsync_supported);
+            Debug.Print("Context supports vsync tear: {0}.", vsync_tear_supported);
 
             base.LoadAll();
         }