From 14cb22a1a4202191d33b0b5d0cc405178232d49a Mon Sep 17 00:00:00 2001
From: kgv <kgv@opencascade.com>
Date: Sat, 17 Sep 2016 13:32:13 +0300
Subject: [PATCH] 0027879: Draw Harness, ViewerTest - disable VSync within
 non-interactive mode

---
 src/ViewerTest/ViewerTest_ViewerCommands.cxx | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/ViewerTest/ViewerTest_ViewerCommands.cxx b/src/ViewerTest/ViewerTest_ViewerCommands.cxx
index ff91e617b2..6992046e1f 100644
--- a/src/ViewerTest/ViewerTest_ViewerCommands.cxx
+++ b/src/ViewerTest/ViewerTest_ViewerCommands.cxx
@@ -558,8 +558,17 @@ TCollection_AsciiString ViewerTest::ViewerInit (const Standard_Integer thePxLeft
     (void)theDisplayName; // avoid warning on unused argument
     SetDisplayConnection (new Aspect_DisplayConnection ());
   #endif
+
+    if (Draw_VirtualWindows)
+    {
+      // don't waste the time waiting for VSync when window is not displayed on the screen
+      ViewerTest_myDefaultCaps.swapInterval = 0;
+      // alternatively we can disable buffer swap at all, but this might be inappropriate for testing
+      //ViewerTest_myDefaultCaps.buffersNoSwap = true;
+    }
     aGraphicDriver = new OpenGl_GraphicDriver (GetDisplayConnection());
     aGraphicDriver->ChangeOptions() = ViewerTest_myDefaultCaps;
+
     ViewerTest_myDrivers.Bind (aViewNames.GetDriverName(), aGraphicDriver);
     toCreateViewer = Standard_True;
   }