GL paint-flushing guard re-work.

Unfortunately, since we can have 2x SalGraphics' on a OutputDevice,
and one of these can be a printer - things got very confused around
which context to glFlush. This de-tangles the various reference-counts.

Change-Id: I1062be0b02a91fc9009deaa3ec29c5dbb227df20
Reviewed-on: https://gerrit.libreoffice.org/18604
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>

3 files changed, 49 insertions, 25 deletions

diff --git a/vcl/source/opengl/OpenGLHelper.cxx b/vcl/source/opengl/OpenGLHelper.cxx
index 5d4b8f77a9c1..114251ce24f4 100644
--- a/vcl/source/opengl/OpenGLHelper.cxx
+++ b/vcl/source/opengl/OpenGLHelper.cxx
@@ -32,7 +32,7 @@
 #include <unordered_map>
 
 #include "svdata.hxx"
-
+#include "salgdi.hxx"
 #include "salinst.hxx"
 #include "opengl/zone.hxx"
 #include "opengl/watchdog.hxx"
@@ -1070,4 +1070,48 @@ GLXFBConfig OpenGLHelper::GetPixmapFBConfig( Display* pDisplay, bool& bInverted
 
 #endif
 
+OutputDevice::PaintScope::PaintScope(OutputDevice *pDev)
+    : pHandle( NULL )
+{
+    if( pDev->mpGraphics || pDev->AcquireGraphics() )
+    {
+        OpenGLContext *pContext = pDev->mpGraphics->BeginPaint();
+        if( pContext )
+        {
+            assert( pContext->mnPainting >= 0 );
+            pContext->mnPainting++;
+            pContext->acquire();
+            pHandle = static_cast<void *>( pContext );
+        }
+    }
+}
+
+/**
+ * Flush all the queued rendering commands to the screen for this context.
+ */
+void OutputDevice::PaintScope::flush()
+{
+    if( pHandle )
+    {
+        OpenGLContext *pContext = static_cast<OpenGLContext *>( pHandle );
+        pHandle = NULL;
+        pContext->mnPainting--;
+        assert( pContext->mnPainting >= 0 );
+        if( pContext->mnPainting == 0 )
+        {
+            pContext->makeCurrent();
+            pContext->AcquireDefaultFramebuffer();
+            glFlush();
+            pContext->swapBuffers();
+            CHECK_GL_ERROR();
+        }
+        pContext->release();
+    }
+}
+
+OutputDevice::PaintScope::~PaintScope()
+{
+    flush();
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/outdev/outdev.cxx b/vcl/source/outdev/outdev.cxx
index 17fa19607647..4f13a3d86902 100644
--- a/vcl/source/outdev/outdev.cxx
+++ b/vcl/source/outdev/outdev.cxx
@@ -845,16 +845,4 @@ bool OutputDevice::DrawEPS( const Point& rPoint, const Size& rSize,
     return bDrawn;
 }
 
-void OutputDevice::BeginPaint()
-{
-    if( mpGraphics || AcquireGraphics() )
-        mpGraphics->BeginPaint();
-}
-
-void OutputDevice::EndPaint()
-{
-    if( mpGraphics || AcquireGraphics() )
-        mpGraphics->EndPaint();
-}
-
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/window/paint.cxx b/vcl/source/window/paint.cxx
index 429711ee7ab9..af1422756a7c 100644
--- a/vcl/source/window/paint.cxx
+++ b/vcl/source/window/paint.cxx
@@ -276,7 +276,7 @@ void PaintHelper::DoPaint(const vcl::Region* pRegion)
         VCL_GL_INFO("vcl.opengl", "PaintHelper::DoPaint on " <<
                     typeid( *m_pWindow ).name() << " '" << m_pWindow->GetText() << "' begin");
 
-        m_pWindow->BeginPaint();
+        OutputDevice::PaintScope aScope( m_pWindow );
 
         // double-buffering: setup the buffer if it does not exist
         if (!pFrameData->mbInBufferedPaint && m_pWindow->SupportsDoubleBuffering())
@@ -306,8 +306,6 @@ void PaintHelper::DoPaint(const vcl::Region* pRegion)
             m_pWindow->Paint(*m_pWindow, m_aPaintRect);
         }
 
-        m_pWindow->EndPaint();
-
         VCL_GL_INFO("vcl.opengl", "PaintHelper::DoPaint end on " <<
                     typeid( *m_pWindow ).name() << " '" << m_pWindow->GetText() << "'");
     }
@@ -629,10 +627,8 @@ void Window::ImplCallOverlapPaint()
     {
         // - RTL - notify ImplCallPaint to check for re-mirroring (CHECKRTL)
         //         because we were called from the Sal layer
-        OutputDevice *pOutDev = GetOutDev();
-        pOutDev->BeginPaint();
+        OutputDevice::PaintScope aScope( GetOutDev() );
         ImplCallPaint(NULL, mpWindowImpl->mnPaintFlags /*| IMPL_PAINT_CHECKRTL */);
-        pOutDev->EndPaint();
     }
 }
 
@@ -651,7 +647,7 @@ IMPL_LINK_NOARG_TYPED(Window, ImplHandlePaintHdl, Idle *, void)
         return;
     }
 
-    BeginPaint();
+    OutputDevice::PaintScope aScope(this);
 
     // save paint events until resizing or initial sizing done
     if (!ImplDoTiledRendering() && mpWindowImpl->mbFrame &&
@@ -664,15 +660,13 @@ IMPL_LINK_NOARG_TYPED(Window, ImplHandlePaintHdl, Idle *, void)
     {
         ImplCallOverlapPaint();
     }
-
-    EndPaint();
 }
 
 IMPL_LINK_NOARG_TYPED(Window, ImplHandleResizeTimerHdl, Idle *, void)
 {
     if( mpWindowImpl->mbReallyVisible )
     {
-        BeginPaint();
+        OutputDevice::PaintScope aScope(this);
 
         ImplCallResize();
         if( ImplDoTiledRendering() )
@@ -684,8 +678,6 @@ IMPL_LINK_NOARG_TYPED(Window, ImplHandleResizeTimerHdl, Idle *, void)
             mpWindowImpl->mpFrameData->maPaintIdle.Stop();
             mpWindowImpl->mpFrameData->maPaintIdle.GetIdleHdl().Call( NULL );
         }
-
-        EndPaint();
     }
 }