From fba72931db258ff3aa464932a2d75c55d340281f Mon Sep 17 00:00:00 2001
From: Michael Meeks <michael.meeks@collabora.com>
Date: Wed, 16 Sep 2015 03:25:05 +0100
Subject: tdf#94252 - avoid switching contexts un-necessarily to reduce
 flicker.

Change-Id: Id4ac387174fa03c5886a990d89fd53a4f18db11c
Reviewed-on: https://gerrit.libreoffice.org/18610
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tor Lillqvist <tml@collabora.com>
---
 vcl/opengl/gdiimpl.cxx | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/vcl/opengl/gdiimpl.cxx b/vcl/opengl/gdiimpl.cxx
index 37b21f36edc1..9ea8a7c87fc8 100644
--- a/vcl/opengl/gdiimpl.cxx
+++ b/vcl/opengl/gdiimpl.cxx
@@ -77,8 +77,17 @@ bool OpenGLSalGraphicsImpl::AcquireContext( )
 {
     ImplSVData* pSVData = ImplGetSVData();
 
+    // We always prefer to bind our VirtualDevice / offscreen graphics
+    // to the current OpenGLContext - to avoid switching contexts.
+    if (mpContext.is() && mbOffscreen)
+    {
+        if (OpenGLContext::hasCurrent() && !mpContext->isCurrent())
+            mpContext.clear();
+    }
+
     if( mpContext.is() )
     {
+        // Check whether the context was reset underneath us.
         if( mpContext->isInitialized() )
             return true;
         mpContext.clear();
-- 
cgit