3 files changed, 32 insertions, 7 deletions
diff --git a/platform/x11/context_gl_x11.cpp b/platform/x11/context_gl_x11.cpp
index 4e00dbf0a8..cd325dfc99 100644
--- a/platform/x11/context_gl_x11.cpp
+++ b/platform/x11/context_gl_x11.cpp
@@ -179,14 +179,38 @@ int ContextGL_X11::get_window_height() {
 }
 
 void ContextGL_X11::set_use_vsync(bool p_use) {
-	GLXDrawable drawable = glXGetCurrentDrawable();
-	//GLXSwapIntervalEXT(x11_display, drawable, p_use?1:0);
-	use_vsync=p_use;
+	static bool setup = false;
+	static PFNGLXSWAPINTERVALEXTPROC glXSwapIntervalEXT = NULL;
+	static PFNGLXSWAPINTERVALSGIPROC glXSwapIntervalMESA = NULL;
+	static PFNGLXSWAPINTERVALSGIPROC glXSwapIntervalSGI = NULL;
+
+	if (!setup) {
+		setup = true;
+		String extensions = glXQueryExtensionsString(x11_display, DefaultScreen(x11_display));
+		if (extensions.find("GLX_EXT_swap_control") != -1)
+			glXSwapIntervalEXT  = (PFNGLXSWAPINTERVALEXTPROC) glXGetProcAddressARB((const GLubyte*)"glXSwapIntervalEXT");
+		if (extensions.find("GLX_MESA_swap_control") != -1)
+			glXSwapIntervalMESA = (PFNGLXSWAPINTERVALSGIPROC) glXGetProcAddressARB((const GLubyte*)"glXSwapIntervalMESA");
+		if (extensions.find("GLX_SGI_swap_control") != -1)
+			glXSwapIntervalSGI  = (PFNGLXSWAPINTERVALSGIPROC) glXGetProcAddressARB((const GLubyte*)"glXSwapIntervalSGI");
+	}
+	int val = p_use ? 1:0;
+	if (glXSwapIntervalMESA) {
+		glXSwapIntervalMESA(val);
+	}
+	else if (glXSwapIntervalSGI) {
+		glXSwapIntervalSGI(val);
+	}
+	else if (glXSwapIntervalEXT) {
+		GLXDrawable drawable = glXGetCurrentDrawable();
+		glXSwapIntervalEXT(x11_display, drawable, val);
+	}
+	else return;
+	use_vsync = p_use;
 }
 bool ContextGL_X11::is_using_vsync() const {
 
-	return false;
-	//return use_vsync;
+	return use_vsync;
 }
 
 
diff --git a/platform/x11/detect.py b/platform/x11/detect.py
index 5a43bf9323..2561e09b9a 100644
--- a/platform/x11/detect.py
+++ b/platform/x11/detect.py
@@ -65,6 +65,7 @@ def get_flags():
 
 	return [
 	('builtin_zlib', 'no'),
+	('glew', 'yes'),
 	("openssl", "yes"),
 	#("theora","no"),
         ]
@@ -147,7 +148,7 @@ def configure(env):
 			env.Append(CPPPATH=['#drivers/freetype/freetype/include'])
 
 
-	env.Append(CPPFLAGS=['-DOPENGL_ENABLED','-DGLEW_ENABLED'])
+	env.Append(CPPFLAGS=['-DOPENGL_ENABLED'])
 
 	if os.system("pkg-config --exists alsa")==0:
 		print("Enabling ALSA")
diff --git a/platform/x11/platform_config.h b/platform/x11/platform_config.h
index aac50c27c2..3b47b2c92d 100644
--- a/platform/x11/platform_config.h
+++ b/platform/x11/platform_config.h
@@ -34,6 +34,6 @@
 #define PTHREAD_BSD_SET_NAME
 #endif
 
-#define GLES2_INCLUDE_H "gl_context/glew.h"
+#define GLES2_INCLUDE_H "gl_context/GL/glew.h"