From 1ee78ecef573c509df22ff81f8371c2aaf1c3cb2 Mon Sep 17 00:00:00 2001
From: Camilla Berglund <elmindreda@users.sourceforge.net>
Date: Mon, 15 Nov 2010 21:17:42 +0100
Subject: [PATCH] Added support for GLX_EXT_swap_control.

---
 readme.html          |  1 +
 src/x11/platform.h   |  2 ++
 src/x11/x11_window.c | 30 ++++++++++++++++++++++++------
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/readme.html b/readme.html
index 1290fefd..0e001b17 100644
--- a/readme.html
+++ b/readme.html
@@ -295,6 +295,7 @@ version of GLFW.</p>
   <li>Removed <code>GLFWCALL</code> and <code>GLFWAPIENTRY</code> macros for stdcall calling convention</li>
   <li>Bugfix: The default OpenGL version in the <code>version</code> test was set to 1.1</li>
   <li>Bugfix: The OpenGL profile and forward-compatibility window parameters were not saved after context creation</li>
+  <li>[X11] Added support for the <code>GLX_EXT_swap_control</code> extension as an alternative to <code>GLX_SGI_swap_control</code></li>
   <li>[X11] Bugfix: Calling <code>glXCreateContextAttribsARB</code> with an unavailable OpenGL version caused the application to terminate with a <code>BadMatch</code> Xlib error</li>
   <li>[Win32] Removed explicit support for versions of Windows older than Windows XP</li>
   <li>[Win32] Bugfix: Window activation and iconification did not work as expected</li>
diff --git a/src/x11/platform.h b/src/x11/platform.h
index 57b10447..05bc2544 100644
--- a/src/x11/platform.h
+++ b/src/x11/platform.h
@@ -100,6 +100,7 @@ typedef struct _GLFWcontextGLX
 
     // GLX extensions
     PFNGLXSWAPINTERVALSGIPROC             SwapIntervalSGI;
+    PFNGLXSWAPINTERVALEXTPROC             SwapIntervalEXT;
     PFNGLXGETFBCONFIGATTRIBSGIXPROC       GetFBConfigAttribSGIX;
     PFNGLXCHOOSEFBCONFIGSGIXPROC          ChooseFBConfigSGIX;
     PFNGLXCREATECONTEXTWITHCONFIGSGIXPROC CreateContextWithConfigSGIX;
@@ -107,6 +108,7 @@ typedef struct _GLFWcontextGLX
     PFNGLXCREATECONTEXTATTRIBSARBPROC     CreateContextAttribsARB;
     GLboolean   has_GLX_SGIX_fbconfig;
     GLboolean   has_GLX_SGI_swap_control;
+    GLboolean   has_GLX_EXT_swap_control;
     GLboolean   has_GLX_ARB_multisample;
     GLboolean   has_GLX_ARB_create_context;
     GLboolean   has_GLX_ARB_create_context_profile;
diff --git a/src/x11/x11_window.c b/src/x11/x11_window.c
index e716129d..8ae0b256 100644
--- a/src/x11/x11_window.c
+++ b/src/x11/x11_window.c
@@ -667,13 +667,25 @@ static int createContext(_GLFWwindow* window,
 
 static void initGLXExtensions(_GLFWwindow* window)
 {
-    if (_glfwPlatformExtensionSupported("GLX_SGI_swap_control"))
+    if (_glfwPlatformExtensionSupported("GLX_EXT_swap_control"))
     {
-        window->GLX.SwapIntervalSGI = (PFNGLXSWAPINTERVALSGIPROC)
-            _glfwPlatformGetProcAddress("glXSwapIntervalSGI");
+        window->GLX.SwapIntervalEXT = (PFNGLXSWAPINTERVALEXTPROC)
+            _glfwPlatformGetProcAddress("glXSwapIntervalEXT");
 
-        if (window->GLX.SwapIntervalSGI)
-            window->GLX.has_GLX_SGI_swap_control = GL_TRUE;
+        if (window->GLX.SwapIntervalEXT)
+            window->GLX.has_GLX_EXT_swap_control = GL_TRUE;
+    }
+
+    if (!window->GLX.has_GLX_EXT_swap_control)
+    {
+        if (_glfwPlatformExtensionSupported("GLX_SGI_swap_control"))
+        {
+            window->GLX.SwapIntervalSGI = (PFNGLXSWAPINTERVALSGIPROC)
+                _glfwPlatformGetProcAddress("glXSwapIntervalSGI");
+
+            if (window->GLX.SwapIntervalSGI)
+                window->GLX.has_GLX_SGI_swap_control = GL_TRUE;
+        }
     }
 
     if (_glfwPlatformExtensionSupported("GLX_SGIX_fbconfig"))
@@ -1684,7 +1696,13 @@ void _glfwPlatformSwapInterval(int interval)
 {
     _GLFWwindow* window = _glfwLibrary.currentWindow;
 
-    if (window->GLX.has_GLX_SGI_swap_control)
+    if (window->GLX.has_GLX_EXT_swap_control)
+    {
+        window->GLX.SwapIntervalEXT(_glfwLibrary.X11.display,
+                                    window->X11.handle,
+                                    interval);
+    }
+    else if (window->GLX.has_GLX_SGI_swap_control)
         window->GLX.SwapIntervalSGI(interval);
 }