Cairo canvas fixes

+ Move BitmapEx construction from an XBitmapCanvas into BitmapEx
where (arguably) it will be easier to re-factor later, treat a
mask fetch failure as if we have no mask
+ Teach the cairo canvas to return a non-pre-multiplied RGB +
separate Alpha BitmapEx when it can to avoid unpleasantness with
the underlying X resources.
+ Add tentative code-path to convert 32bit color Bitmaps into
24bit color, to avoid confusing X

Change-Id: Iaf6998c796aea6d73c57bed2bc03152d9636d5f5

Conflicts:
vcl/source/gdi/gdimtf.cxx

4 files changed, 163 insertions, 94 deletions

diff --git a/canvas/source/cairo/cairo_canvasbitmap.cxx b/canvas/source/cairo/cairo_canvasbitmap.cxx
index 91f61940dc1d..062af840b595 100644
--- a/canvas/source/cairo/cairo_canvasbitmap.cxx
+++ b/canvas/source/cairo/cairo_canvasbitmap.cxx
@@ -23,6 +23,9 @@
 
 #include "cairo_canvasbitmap.hxx"
 
+#include <vcl/bmpacc.hxx>
+#include <vcl/bitmapex.hxx>
+
 #ifdef CAIRO_HAS_XLIB_SURFACE
 # include "cairo_xlib_cairo.hxx"
 #elif defined CAIRO_HAS_QUARTZ_SURFACE
@@ -144,7 +147,67 @@ namespace cairocanvas
         {
             case 0:
             {
-                aRV = uno::Any( reinterpret_cast<sal_Int64>( (BitmapEx*) NULL ) );
+                aRV = uno::Any( reinterpret_cast<sal_Int64>( (BitmapEx *) NULL ) );
+                if ( !mbHasAlpha )
+                    break;
+
+                ::Size aSize( maSize.getX(), maSize.getY() );
+                // FIXME: if we could teach VCL/ about cairo handles, life could
+                // be significantly better here perhaps.
+                cairo_surface_t *pPixels;
+                pPixels = cairo_image_surface_create( CAIRO_FORMAT_ARGB32,
+                                                      aSize.Width(), aSize.Height() );
+                cairo_t *pCairo = cairo_create( pPixels );
+                if( !pPixels || !pCairo )
+                    break;
+
+                // suck ourselves from the X server to this buffer so then we can fiddle with
+                // Alpha to turn it into the ultra-lame vcl required format and then push it
+                // all back again later at vast expense [ urgh ]
+                cairo_set_source_surface( pCairo, getSurface()->getCairoSurface().get(), 0, 0 );
+                cairo_set_operator( pCairo, CAIRO_OPERATOR_SOURCE );
+                cairo_paint( pCairo );
+
+                ::Bitmap aRGB( aSize, 24 );
+                ::AlphaMask aMask( aSize );
+
+                BitmapWriteAccess *pRGBWrite( aRGB.AcquireWriteAccess() );
+                BitmapWriteAccess *pMaskWrite( aMask.AcquireWriteAccess() );
+
+                unsigned char *pSrc = cairo_image_surface_get_data( pPixels );
+                unsigned int nStride = cairo_image_surface_get_stride( pPixels );
+                for( unsigned long y = 0; y < (unsigned long) aSize.Height(); y++ )
+                {
+                    sal_uInt32 *pPix = (sal_uInt32 *)(pSrc + nStride * y);
+                    for( unsigned long x = 0; x < (unsigned long) aSize.Width(); x++ )
+                    {
+                        sal_uInt8 nAlpha = (*pPix >> 24);
+                        sal_uInt8 nR = (*pPix >> 16) & 0xff;
+                        sal_uInt8 nG = (*pPix >> 8) & 0xff;
+                        sal_uInt8 nB = *pPix & 0xff;
+                        if( nAlpha != 0 && nAlpha != 255 )
+                        {
+//                            fprintf (stderr, "From A(0x%.2x) 0x%.2x 0x%.2x 0x%.2x -> ",
+//                                     nAlpha, nR, nG, nB );
+                            // Cairo uses pre-multiplied alpha - we do not => re-multiply
+                            nR = (sal_uInt8) MinMax( ((sal_uInt32)nR * 255) / nAlpha, 0, 255 );
+                            nG = (sal_uInt8) MinMax( ((sal_uInt32)nG * 255) / nAlpha, 0, 255 );
+                            nB = (sal_uInt8) MinMax( ((sal_uInt32)nB * 255) / nAlpha, 0, 255 );
+//                            fprintf (stderr, "0x%.2x 0x%.2x 0x%.2x\n", nR, nG, nB );
+                        }
+                        pRGBWrite->SetPixel( y, x, BitmapColor( nR, nG, nB ) );
+                        pMaskWrite->SetPixel( y, x, BitmapColor( 255 - nAlpha ) );
+                        pPix++;
+                    }
+                }
+                aMask.ReleaseAccess( pMaskWrite );
+                aRGB.ReleaseAccess( pRGBWrite );
+
+                ::BitmapEx *pBitmapEx = new ::BitmapEx( aRGB, aMask );
+
+                cairo_surface_destroy( pPixels );
+
+                aRV = uno::Any( reinterpret_cast<sal_Int64>( pBitmapEx ) );
                 break;
             }
             case 1:
@@ -179,71 +242,9 @@ namespace cairocanvas
             }
             case 2:
             {
-#ifdef CAIRO_HAS_XLIB_SURFACE
-                uno::Sequence< uno::Any > args( 3 );
-                SurfaceSharedPtr pAlphaSurface = mpSurfaceProvider->createSurface( maSize, CAIRO_CONTENT_COLOR );
-                CairoSharedPtr   pAlphaCairo = pAlphaSurface->getCairo();
-                X11Surface* pXlibSurface=dynamic_cast<X11Surface*>(pAlphaSurface.get());
-                OSL_ASSERT(pXlibSurface);
-
-                // create RGB image (levels of gray) of alpha channel of original picture
-                cairo_set_source_rgba( pAlphaCairo.get(), 1, 1, 1, 1 );
-                cairo_set_operator( pAlphaCairo.get(), CAIRO_OPERATOR_SOURCE );
-                cairo_paint( pAlphaCairo.get() );
-                cairo_set_source_surface( pAlphaCairo.get(), mpBufferSurface->getCairoSurface().get(), 0, 0 );
-                cairo_set_operator( pAlphaCairo.get(), CAIRO_OPERATOR_XOR );
-                cairo_paint( pAlphaCairo.get() );
-                pAlphaCairo.reset();
-
-                X11PixmapSharedPtr pPixmap = pXlibSurface->getPixmap();
-                args[0] = uno::Any( true );
-                args[1] = ::com::sun::star::uno::Any( pPixmap->mhDrawable );
-                args[2] = ::com::sun::star::uno::Any( sal_Int32( pXlibSurface->getDepth () ) );
-                pPixmap->clear(); // caller takes ownership of pixmap
-
-                // return pixmap and alphachannel pixmap - it will be used in BitmapEx
-                aRV = uno::Any( args );
-#elif defined CAIRO_HAS_QUARTZ_SURFACE
-                SurfaceSharedPtr pAlphaSurface = mpSurfaceProvider->createSurface( maSize, CAIRO_CONTENT_COLOR );
-                CairoSharedPtr   pAlphaCairo = pAlphaSurface->getCairo();
-                QuartzSurface* pQuartzSurface=dynamic_cast<QuartzSurface*>(pAlphaSurface.get());
-                OSL_ASSERT(pQuartzSurface);
-
-                // create RGB image (levels of gray) of alpha channel of original picture
-                cairo_set_source_rgba( pAlphaCairo.get(), 1, 1, 1, 1 );
-                cairo_set_operator( pAlphaCairo.get(), CAIRO_OPERATOR_SOURCE );
-                cairo_paint( pAlphaCairo.get() );
-                cairo_set_source_surface( pAlphaCairo.get(), mpBufferSurface->getCairoSurface().get(), 0, 0 );
-                cairo_set_operator( pAlphaCairo.get(), CAIRO_OPERATOR_XOR );
-                cairo_paint( pAlphaCairo.get() );
-                pAlphaCairo.reset();
-
-                uno::Sequence< uno::Any > args( 1 );
-                args[0] = uno::Any( sal_IntPtr (pQuartzSurface->getCGContext()) );
-                // return ??? and alphachannel ??? - it will be used in BitmapEx
-                aRV = uno::Any( args );
-#elif defined CAIRO_HAS_WIN32_SURFACE
-                SurfaceSharedPtr pAlphaSurface = mpSurfaceProvider->createSurface( maSize, CAIRO_CONTENT_COLOR );
-                CairoSharedPtr   pAlphaCairo = pAlphaSurface->getCairo();
-
-                // create RGB image (levels of gray) of alpha channel of original picture
-                cairo_set_source_rgba( pAlphaCairo.get(), 1, 1, 1, 1 );
-                cairo_set_operator( pAlphaCairo.get(), CAIRO_OPERATOR_SOURCE );
-                cairo_paint( pAlphaCairo.get() );
-                cairo_set_source_surface( pAlphaCairo.get(), mpBufferSurface->getCairoSurface().get(), 0, 0 );
-                cairo_set_operator( pAlphaCairo.get(), CAIRO_OPERATOR_XOR );
-                cairo_paint( pAlphaCairo.get() );
-                pAlphaCairo.reset();
-
-                // cant seem to retrieve HBITMAP from cairo. copy content then
-                uno::Sequence< uno::Any > args( 1 );
-                args[1] = uno::Any( sal_Int64(surface2HBitmap(pAlphaSurface,maSize)) );
-
-                aRV = uno::Any( args );
-                // caller frees the bitmap
-#else
-# error Please define fast prop retrieval for your platform!
-#endif
+                // Always return nothing - for the RGB surface support.
+                // Alpha code paths go via the above case 0.
+                aRV = uno::Any();
                 break;
             }
         }
diff --git a/vcl/inc/vcl/bitmapex.hxx b/vcl/inc/vcl/bitmapex.hxx
index 9eaaf618200c..d0c1f98a8904 100644
--- a/vcl/inc/vcl/bitmapex.hxx
+++ b/vcl/inc/vcl/bitmapex.hxx
@@ -25,6 +25,12 @@
 #include <vcl/alpha.hxx>
 #include <tools/color.hxx>
 
+#include <com/sun/star/uno/Reference.hxx>
+
+namespace com { namespace sun { namespace star { namespace rendering {
+    class XBitmapCanvas;
+} } } }
+
 // -------------------
 // - TransparentType -
 // -------------------
@@ -382,6 +388,11 @@ public:
     friend VCL_DLLPUBLIC SvStream&  operator<<( SvStream& rOStm, const BitmapEx& rBitmapEx );
     friend VCL_DLLPUBLIC SvStream&  operator>>( SvStream& rIStm, BitmapEx& rBitmapEx );
     static BitmapEx AutoScaleBitmap(BitmapEx & aBitmap, const long aStandardSize);
+
+    /// populate from a canvas implementation
+    bool Create( const ::com::sun::star::uno::Reference<
+                 ::com::sun::star::rendering::XBitmapCanvas > &xBitmapCanvas,
+                 const Size &rSize );
 };
 
 #endif // _SV_BITMAPEX_HXX
diff --git a/vcl/source/gdi/bitmapex.cxx b/vcl/source/gdi/bitmapex.cxx
index 45fe0aa925ec..59fc06a503ed 100644
--- a/vcl/source/gdi/bitmapex.cxx
+++ b/vcl/source/gdi/bitmapex.cxx
@@ -17,7 +17,6 @@
  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  */
 
-
 #include <ctype.h>
 
 #include <rtl/crc.h>
@@ -39,6 +38,13 @@
 #include <image.h>
 #include <impimagetree.hxx>
 
+// BitmapEx::Create
+#include <salbmp.hxx>
+#include <salinst.hxx>
+#include <svdata.hxx>
+#include <com/sun/star/beans/XFastPropertySet.hpp>
+using namespace ::com::sun::star;
+
 BitmapEx::BitmapEx() :
         eTransparent( TRANSPARENT_NONE ),
         bAlpha      ( sal_False )
@@ -856,4 +862,74 @@ SvStream& operator>>( SvStream& rIStm, BitmapEx& rBitmapEx )
     return rIStm;
 }
 
+// Shift alpha transparent pixels between cppcanvas/ implementations
+// and vcl in a generally grotesque and under-performing fashion
+bool BitmapEx::Create( const ::com::sun::star::uno::Reference<
+                       ::com::sun::star::rendering::XBitmapCanvas > &xBitmapCanvas,
+                       const Size &rSize )
+{
+    SetEmpty();
+    Size aSize( rSize );
+
+    uno::Reference< beans::XFastPropertySet > xFastPropertySet( xBitmapCanvas, uno::UNO_QUERY );
+    if( xFastPropertySet.get() )
+    {
+        // 0 means get BitmapEx
+        uno::Any aAny = xFastPropertySet->getFastPropertyValue( 0 );
+        BitmapEx* pBitmapEx = (BitmapEx*) *reinterpret_cast<const sal_Int64*>(aAny.getValue());
+        if( pBitmapEx )
+        {
+            *this = *pBitmapEx;
+            delete pBitmapEx;
+            return true;
+        }
+    }
+
+    SalBitmap* pSalBmp, *pSalMask;
+
+    pSalBmp = ImplGetSVData()->mpDefInst->CreateSalBitmap();
+    pSalMask = ImplGetSVData()->mpDefInst->CreateSalBitmap();
+
+    if( pSalBmp->Create( xBitmapCanvas, aSize ) )
+    {
+#ifdef CLAMP_BITDEPTH_PARANOIA
+        // did we get alpha mixed up in the bitmap itself
+        // eg. Cairo Canvas ... yes performance of this is awful.
+        if( pSalBmp->GetBitCount() > 24 )
+        {
+            // Format convert the pixels with generic code
+            Bitmap aSrcPixels( pSalBmp );
+            aBitmap = Bitmap( rSize, 24 );
+            BitmapReadAccess aSrcRead( aSrcPixels );
+            BitmapWriteAccess aDestWrite( aBitmap );
+            aDestWrite.CopyBuffer( aSrcRead );
+        }
+        else
+#endif
+            aBitmap = Bitmap( pSalBmp );
+
+        aBitmapSize = rSize;
+        if ( pSalMask->Create( xBitmapCanvas, aSize, true ) )
+        {
+            aMask = Bitmap( pSalMask );
+            bAlpha = sal_True;
+            aBitmapSize = rSize;
+            eTransparent = !aMask ? TRANSPARENT_NONE : TRANSPARENT_BITMAP;
+
+            return true;
+        }
+        else
+        {
+            bAlpha = sal_False;
+            eTransparent = TRANSPARENT_NONE;
+            return true;
+        }
+    }
+
+    delete pSalBmp;
+    delete pSalMask;
+
+    return false;
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/gdi/gdimtf.cxx b/vcl/source/gdi/gdimtf.cxx
index 33e304bbc150..f43b6ca4f6b2 100644
--- a/vcl/source/gdi/gdimtf.cxx
+++ b/vcl/source/gdi/gdimtf.cxx
@@ -487,35 +487,16 @@ bool GDIMetaFile::ImplPlayWithRenderer( OutputDevice* pOut, const Point& rPos, S
                         xMtfFastPropertySet->setFastPropertyValue( 0, uno::Any( reinterpret_cast<sal_Int64>( this ) ) );
 
                     xMtfRenderer->draw( rDestSize.Width(), rDestSize.Height() );
+                }
 
-                    uno::Reference< beans::XFastPropertySet > xFastPropertySet( xBitmapCanvas, uno::UNO_QUERY );
-                    if( xFastPropertySet.get() )
-                    {
-                        // 0 means get BitmapEx
-                        uno::Any aAny = xFastPropertySet->getFastPropertyValue( 0 );
-                        BitmapEx* pBitmapEx = (BitmapEx*) *reinterpret_cast<const sal_Int64*>(aAny.getValue());
-                        if( pBitmapEx ) {
-                            pOut->DrawBitmapEx( rPos, rLogicDestSize, *pBitmapEx );
-                            delete pBitmapEx;
-                            return true;
-                        }
-                    }
-
-                    SalBitmap* pSalBmp = ImplGetSVData()->mpDefInst->CreateSalBitmap();
-                    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 );
+                BitmapEx aBitmapEx;
+                if( aBitmapEx.Create( xBitmapCanvas, aSize ) )
+                {
+                    if ( pOut->GetMapMode() == MAP_PIXEL )
                         pOut->DrawBitmapEx( rPos, aBitmapEx );
-                        return true;
-                    }
-
-                    delete pSalBmp;
-                    delete pSalMask;
+                    else
+                        pOut->DrawBitmapEx( rPos, rLogicDestSize, aBitmapEx );
+                    return true;
                 }
             }
         }