From f2dc40abdd38d06c03be25c0f175a3a41db28253 Mon Sep 17 00:00:00 2001
From: thefiddler <stapostol@gmail.com>
Date: Tue, 29 Apr 2014 08:31:47 +0200
Subject: [PATCH] [OpenTK] Query the driver for VSyncMode getter

Otherwise, the user could call Context.SwapInterval directly, causing
the vsync property to fall out of sync.
---
 Source/OpenTK/GameWindow.cs | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/Source/OpenTK/GameWindow.cs b/Source/OpenTK/GameWindow.cs
index 323f97c..41029bc 100644
--- a/Source/OpenTK/GameWindow.cs
+++ b/Source/OpenTK/GameWindow.cs
@@ -98,8 +98,6 @@ namespace OpenTK
 
         bool is_running_slowly; // true, when UpdatePeriod cannot reach TargetUpdatePeriod
 
-        VSyncMode vsync;
-
         FrameEventArgs update_args = new FrameEventArgs();
         FrameEventArgs render_args = new FrameEventArgs();
 
@@ -884,7 +882,18 @@ namespace OpenTK
             {
                 EnsureUndisposed();
                 GraphicsContext.Assert();
-                return vsync;
+                if (Context.SwapInterval < 0)
+                {
+                    return VSyncMode.Adaptive;
+                }
+                else if (Context.SwapInterval == 0)
+                {
+                    return VSyncMode.Off;
+                }
+                else
+                {
+                    return VSyncMode.On;
+                }
             }
             set
             {
@@ -904,7 +913,6 @@ namespace OpenTK
                         Context.SwapInterval = -1;
                         break;
                 }
-                vsync = value;
             }
         }
 
-- 
2.7.4