fix emf transparency handling (bnc#820385)

46e53913e9dcc84ffed8fb5f1b4959c70c7e5649 fixed some transparency emf problems
on X11, it however did it by implementing alpha support in X11SalBitmap only
and made generic code rely on it. Now it doesn't work at least on Windows,
after reverting it works on Windows but not on X11. As I have no idea what
the real problem is, at least keep both code paths.

Change-Id: I2f2cf247becfcd777b4f3d129efe4d6a5d641f7b

2 files changed, 33 insertions, 5 deletions

diff --git a/vcl/inc/salbmp.hxx b/vcl/inc/salbmp.hxx
index 03f9af938c94..4db53dc1571e 100644
--- a/vcl/inc/salbmp.hxx
+++ b/vcl/inc/salbmp.hxx
@@ -48,7 +48,6 @@ public:
                                     Size& rSize,
                                     bool bMask = false ) = 0;
     virtual bool            HasAlpha() const { return false; }
-    virtual void            SetHasAlpha( bool ) { }
     virtual void            Destroy() = 0;
     virtual Size            GetSize() const = 0;
     virtual sal_uInt16          GetBitCount() const = 0;
diff --git a/vcl/source/gdi/gdimtf.cxx b/vcl/source/gdi/gdimtf.cxx
index 526196dc1054..63b2b78e97d5 100644
--- a/vcl/source/gdi/gdimtf.cxx
+++ b/vcl/source/gdi/gdimtf.cxx
@@ -48,6 +48,14 @@
 #include <com/sun/star/graphic/XGraphicRenderer.hpp>
 #include <comphelper/processfactory.hxx>
 
+#ifdef UNX
+#include <tools/prex.h>
+#include "unx/Xproto.h"
+#include <tools/postx.h>
+#include <unx/salunx.h>
+#include <unx/salbmp.h>
+#endif
+
 using namespace com::sun::star;
 
 // -----------
@@ -494,18 +502,39 @@ bool GDIMetaFile::ImplPlayWithRenderer( OutputDevice* pOut, const Point& rPos, S
                     }
 
                     SalBitmap* pSalBmp = ImplGetSVData()->mpDefInst->CreateSalBitmap();
-                    pSalBmp->SetHasAlpha( true );
-
-                    if( pSalBmp->Create( xBitmapCanvas, aSize ) )
+                    // I don't quite understand this, but the old code didn't work properly on X11 when alpha was used,
+                    // and the commit that changed to the new code relied on alpha support in bitmap
+                    // (which that commit implemented only in X11SalBitmap) and so it didn't work on Windows.
+                    // So keep both.
+#ifdef UNX
+                    X11SalBitmap* X11Bmp = static_cast< X11SalBitmap* >( pSalBmp );
+                    X11Bmp->SetHasAlpha( true );
+                    if( X11Bmp->Create( xBitmapCanvas, aSize ) )
                     {
-                        Bitmap aBitmap( pSalBmp );
+                        Bitmap aBitmap( X11Bmp );
                         if ( pOut->GetMapMode() == MAP_PIXEL )
                             pOut->DrawBitmap( rPos, aBitmap );
                         else
                             pOut->DrawBitmap( rPos, rLogicDestSize, aBitmap );
                         return true;
                     }
+#else
+                    SalBitmap* pSalMask = ImplGetSVData()->mpDefInst->CreateSalBitmap();
 
+                    if( pSalBmp->Create( xBitmapCanvas, aSize ) && pSalMask->Create( xBitmapCanvas, aSize, true ) )
+                    {
+                        Bitmap aBitmap( pSalBmp );
+                        Bitmap aMask( pSalMask );
+                        AlphaMask aAlphaMask( aMask );
+                        BitmapEx aBitmapEx( aBitmap, aAlphaMask );
+                        if ( pOut->GetMapMode() == MAP_PIXEL )
+                            pOut->DrawBitmapEx( rPos, aBitmapEx );
+                        else
+                            pOut->DrawBitmapEx( rPos, rLogicDestSize, aBitmapEx );
+                        return true;
+                    }
+                    delete pSalMask;
+#endif
                     delete pSalBmp;
                 }
             }