4 files changed, 16 insertions, 2 deletions
diff --git a/indra/llwindow/llwindow.cpp b/indra/llwindow/llwindow.cpp
index f4678a70c5..c5725677b4 100644
--- a/indra/llwindow/llwindow.cpp
+++ b/indra/llwindow/llwindow.cpp
@@ -117,7 +117,8 @@ LLWindow::LLWindow(LLWindowCallbacks* callbacks, BOOL fullscreen, U32 flags)
 	  mSwapMethod(SWAP_METHOD_UNDEFINED),
 	  mHideCursorPermanent(FALSE),
 	  mFlags(flags),
-	  mHighSurrogate(0)
+	  mHighSurrogate(0),
+	  mRefreshRate(0)
 {
 }
 
diff --git a/indra/llwindow/llwindow.h b/indra/llwindow/llwindow.h
index 802a3b5213..ac4848579f 100644
--- a/indra/llwindow/llwindow.h
+++ b/indra/llwindow/llwindow.h
@@ -197,6 +197,8 @@ public:
     // windows only DirectInput8 for joysticks
     virtual void* getDirectInput8() { return NULL; };
     virtual bool getInputDevices(U32 device_type_filter, void * devices_callback, void* userdata) { return false; };
+
+    virtual S32 getRefreshRate() { return mRefreshRate; }
 protected:
 	LLWindow(LLWindowCallbacks* callbacks, BOOL fullscreen, U32 flags);
 	virtual ~LLWindow();
@@ -230,6 +232,7 @@ protected:
 	U16			mHighSurrogate;
 	S32			mMinWindowWidth;
 	S32			mMinWindowHeight;
+    S32         mRefreshRate;
 
  	// Handle a UTF-16 encoding unit received from keyboard.
  	// Converting the series of UTF-16 encoding units to UTF-32 data,
diff --git a/indra/llwindow/llwindowmacosx.cpp b/indra/llwindow/llwindowmacosx.cpp
index a0fc91399b..2c841d4703 100644
--- a/indra/llwindow/llwindowmacosx.cpp
+++ b/indra/llwindow/llwindowmacosx.cpp
@@ -49,6 +49,8 @@ BOOL gHiDPISupport = TRUE;
 const S32	BITS_PER_PIXEL = 32;
 const S32	MAX_NUM_RESOLUTIONS = 32;
 
+const S32   DEFAULT_REFRESH_RATE = 60;
+
 namespace
 {
     NSKeyEventRef mRawKeyEvent = NULL;
@@ -654,6 +656,13 @@ BOOL LLWindowMacOSX::createContext(int x, int y, int width, int height, int bits
 		}
 	}
 
+    mRefreshRate = CGDisplayModeGetRefreshRate(CGDisplayCopyDisplayMode(mDisplay));
+    if(mRefreshRate == 0)
+    {
+        //consider adding more appropriate fallback later
+        mRefreshRate = DEFAULT_REFRESH_RATE;
+    }
+
 	// Disable vertical sync for swap
     toggleVSync(enable_vsync);
 
diff --git a/indra/llwindow/llwindowwin32.cpp b/indra/llwindow/llwindowwin32.cpp
index 6f67b131d1..2e560ddb0a 100644
--- a/indra/llwindow/llwindowwin32.cpp
+++ b/indra/llwindow/llwindowwin32.cpp
@@ -583,7 +583,7 @@ LLWindowWin32::LLWindowWin32(LLWindowCallbacks* callbacks,
 	{
 		current_refresh = 60;
 	}
-
+    mRefreshRate = current_refresh;
 	//-----------------------------------------------------------------------
 	// Drop resolution and go fullscreen
 	// use a display mode with our desired size and depth, with a refresh
@@ -1061,6 +1061,7 @@ BOOL LLWindowWin32::switchContext(BOOL fullscreen, const LLCoordScreen& size, BO
     {
         current_refresh = 60;
     }
+    mRefreshRate = current_refresh;
 
     gGLManager.shutdownGL();
     //destroy gl context