[Render] Allow buffer age of 0 by clean out after render

xbmc/guilib/GUIWindowManager.cpp

@@ -1368,20 +1368,14 @@ bool CGUIWindowManager::Render()
   int bufferAge = CServiceBroker::GetWinSystem()->GetBufferAge();
   bool visualizeDirtyRegions =
       CServiceBroker::GetSettingsComponent()->GetAdvancedSettings()->m_guiVisualizeDirtyRegions;
-  if (visualizeDirtyRegions)
-    bufferAge = 20;
-  if (bufferAge)
-    m_tracker.CleanMarkedRegions(bufferAge + 1);
-  else
-    m_tracker.CleanMarkedRegions(10);
 
   CDirtyRegionList dirtyRegions = m_tracker.GetDirtyRegions();
   CServiceBroker::GetWinSystem()->SetDirtyRegions(dirtyRegions);
 
   bool hasRendered = false;
   // If we visualize the regions we will always render the entire viewport
   // If the buffer age is zero, the current content is undefined and has to be rendered
-  if (visualizeDirtyRegions || bufferAge == 0 ||
+  if (visualizeDirtyRegions ||
       CServiceBroker::GetSettingsComponent()->GetAdvancedSettings()->m_guiAlgorithmDirtyRegions ==
           DIRTYREGION_SOLVER_FILL_VIEWPORT_ALWAYS)
   {
@@ -1418,8 +1412,11 @@ bool CGUIWindowManager::Render()
       CGUITexture::DrawQuad(i, 0x0fff0000);
     for (const auto& i : dirtyRegions)
       CGUITexture::DrawQuad(i, 0x4c00ff00);
+    bufferAge = 20;
   }
 
+  m_tracker.CleanMarkedRegions(bufferAge);
+
   return hasRendered;
 }