Extract slow path of DrawDeviceAlphaBitmap into its own method

Additioanlly cleanup and use ScopedReadAccess

Change-Id: Ia3365f4dc968368bdd90d4398188bffe2d56e89b

2 files changed, 143 insertions, 116 deletions

diff --git a/include/vcl/outdev.hxx b/include/vcl/outdev.hxx
index 5ce1a27515a8..f8fd837f3bf3 100644
--- a/include/vcl/outdev.hxx
+++ b/include/vcl/outdev.hxx
@@ -1406,6 +1406,12 @@ private:
                                     const Point& rSrcPtPixel,
                                     const Size& rSrcSizePixel );
 
+    SAL_DLLPRIVATE void DrawDeviceAlphaBitmapSlowPath(
+                                const Bitmap& rBitmap, const AlphaMask& rAlpha,
+                                Rectangle aDstRect, Rectangle aBmpRect,
+                                Size& aOutSz, Point& aOutPt);
+
+
     SAL_DLLPRIVATE bool         BlendBitmap(
                                     const SalTwoRect&   rPosAry,
                                     const Bitmap&       rBmp );
diff --git a/vcl/source/outdev/bitmap.cxx b/vcl/source/outdev/bitmap.cxx
index 680f36231c5b..50877bea8011 100644
--- a/vcl/source/outdev/bitmap.cxx
+++ b/vcl/source/outdev/bitmap.cxx
@@ -604,36 +604,37 @@ void OutputDevice::DrawDeviceAlphaBitmap( const Bitmap& rBmp, const AlphaMask& r
                                     const Point& rDestPt, const Size& rDestSize,
                                     const Point& rSrcPtPixel, const Size& rSrcSizePixel )
 {
-    Point       aOutPt( LogicToPixel( rDestPt ) );
-    Size        aOutSz( LogicToPixel( rDestSize ) );
-    Rectangle   aDstRect( Point(), GetOutputSizePixel() );
-    const bool  bHMirr = aOutSz.Width() < 0;
-    const bool  bVMirr = aOutSz.Height() < 0;
+    Point     aOutPt(LogicToPixel(rDestPt));
+    Size      aOutSz(LogicToPixel(rDestSize));
+    Rectangle aDstRect(Point(), GetOutputSizePixel());
+
+    const bool bHMirr = aOutSz.Width() < 0;
+    const bool bVMirr = aOutSz.Height() < 0;
 
     ClipToPaintRegion(aDstRect);
 
-    if( bHMirr )
+    if (bHMirr)
     {
         aOutSz.Width() = -aOutSz.Width();
-        aOutPt.X() -= ( aOutSz.Width() - 1L );
+        aOutPt.X() -= aOutSz.Width() - 1L;
     }
 
-    if( bVMirr )
+    if (bVMirr)
     {
         aOutSz.Height() = -aOutSz.Height();
-        aOutPt.Y() -= ( aOutSz.Height() - 1L );
+        aOutPt.Y() -= aOutSz.Height() - 1L;
     }
 
-    if( !aDstRect.Intersection( Rectangle( aOutPt, aOutSz ) ).IsEmpty() )
+    if (!aDstRect.Intersection(Rectangle(aOutPt, aOutSz)).IsEmpty())
     {
         static const char* pDisableNative = getenv( "SAL_DISABLE_NATIVE_ALPHA");
         // #i83087# Naturally, system alpha blending cannot work with
         // separate alpha VDev
         bool bTryDirectPaint(!pDisableNative && !bHMirr && !bVMirr);
 
-        if(bTryDirectPaint)
+        if (bTryDirectPaint)
         {
-            Point aRelPt = aOutPt + Point( mnOutOffX, mnOutOffY );
+            Point aRelPt = aOutPt + Point(mnOutOffX, mnOutOffY);
             SalTwoRect aTR(
                 rSrcPtPixel.X(), rSrcPtPixel.Y(),
                 rSrcSizePixel.Width(), rSrcSizePixel.Height(),
@@ -644,19 +645,19 @@ void OutputDevice::DrawDeviceAlphaBitmap( const Bitmap& rBmp, const AlphaMask& r
             SalBitmap* pSalAlphaBmp = rAlpha.ImplGetImpBitmap()->ImplGetSalBitmap();
 
             // try the blen the alpha bitmap with the alpha virtual device
-            if( mpAlphaVDev )
+            if (mpAlphaVDev)
             {
                 Bitmap aAlphaBitmap( mpAlphaVDev->GetBitmap( aRelPt, aOutSz ) );
                 SalBitmap* pSalAlphaBmp2 = aAlphaBitmap.ImplGetImpBitmap()->ImplGetSalBitmap();
-                if( mpGraphics->BlendAlphaBitmap( aTR, *pSalSrcBmp, *pSalAlphaBmp, *pSalAlphaBmp2, this ) )
+                if (mpGraphics->BlendAlphaBitmap(aTR, *pSalSrcBmp, *pSalAlphaBmp, *pSalAlphaBmp2, this))
                 {
-                    mpAlphaVDev->BlendBitmap( aTR, rAlpha );
+                    mpAlphaVDev->BlendBitmap(aTR, rAlpha);
                     return;
                 }
             }
             else
             {
-                if (mpGraphics->DrawAlphaBitmap( aTR, *pSalSrcBmp, *pSalAlphaBmp, this ))
+                if (mpGraphics->DrawAlphaBitmap(aTR, *pSalSrcBmp, *pSalAlphaBmp, this))
                     return;
             }
         }
@@ -664,122 +665,142 @@ void OutputDevice::DrawDeviceAlphaBitmap( const Bitmap& rBmp, const AlphaMask& r
         // we need to make sure OpenGL never reaches this slow code path
         assert(!OpenGLHelper::isVCLOpenGLEnabled());
 
-        VirtualDevice* pOldVDev = mpAlphaVDev;
-
-        Rectangle aBmpRect( Point(), rBmp.GetSizePixel() );
+        Rectangle aBmpRect(Point(), rBmp.GetSizePixel());
         if (!aBmpRect.Intersection(Rectangle(rSrcPtPixel, rSrcSizePixel)).IsEmpty())
         {
-            // The scaling in this code path produces really ugly results - it
-            // does the most trivial scaling with no smoothing.
-
-            GDIMetaFile*    pOldMetaFile = mpMetaFile;
-            const bool      bOldMap = mbMap;
-            mpMetaFile = NULL; // fdo#55044 reset before GetBitmap!
-            mbMap = false;
-            Bitmap          aBmp( GetBitmap( aDstRect.TopLeft(), aDstRect.GetSize() ) );
-
-            // #109044# The generated bitmap need not necessarily be
-            // of aDstRect dimensions, it's internally clipped to
-            // window bounds. Thus, we correct the dest size here,
-            // since we later use it (in nDstWidth/Height) for pixel
-            // access)
-            // #i38887# reading from screen may sometimes fail
-            if( aBmp.ImplGetImpBitmap() )
-                aDstRect.SetSize( aBmp.GetSizePixel() );
-
-            BitmapColor     aDstCol;
-            const long      nSrcWidth = aBmpRect.GetWidth(), nSrcHeight = aBmpRect.GetHeight();
-            const long      nDstWidth = aDstRect.GetWidth(), nDstHeight = aDstRect.GetHeight();
-            const long      nOutWidth = aOutSz.Width(), nOutHeight = aOutSz.Height();
-            // calculate offset in original bitmap
-            // in RTL case this is a little more complicated since the contents of the
-            // bitmap is not mirrored (it never is), however the paint region and bmp region
-            // are in mirrored coordinates, so the intersection of (aOutPt,aOutSz) with these
-            // is content wise somewhere else and needs to take mirroring into account
-            const long      nOffX = IsRTLEnabled()
-                                    ? aOutSz.Width() - aDstRect.GetWidth() - (aDstRect.Left() - aOutPt.X())
-                                    : aDstRect.Left() - aOutPt.X(),
-                            nOffY = aDstRect.Top() - aOutPt.Y();
-            long            nX, nOutX, nY, nOutY;
-            long            nMirrOffX = 0;
-            long            nMirrOffY = 0;
-            boost::scoped_array<long> pMapX(new long[ nDstWidth ]);
-            boost::scoped_array<long> pMapY(new long[ nDstHeight ]);
-
-            // create horizontal mapping table
-            if( bHMirr )
-                nMirrOffX = ( aBmpRect.Left() << 1 ) + nSrcWidth - 1;
-
-            for( nX = 0L, nOutX = nOffX; nX < nDstWidth; nX++, nOutX++ )
-            {
-                pMapX[ nX ] = aBmpRect.Left() + nOutX * nSrcWidth / nOutWidth;
-                if( bHMirr )
-                    pMapX[ nX ] = nMirrOffX - pMapX[ nX ];
-            }
+            DrawDeviceAlphaBitmapSlowPath(rBmp, rAlpha, aDstRect, aBmpRect, aOutSz, aOutPt);
+        }
+    }
+}
 
-            // create vertical mapping table
-            if( bVMirr )
-                nMirrOffY = ( aBmpRect.Top() << 1 ) + nSrcHeight - 1;
+void OutputDevice::DrawDeviceAlphaBitmapSlowPath(const Bitmap& rBitmap, const AlphaMask& rAlpha, Rectangle aDstRect, Rectangle aBmpRect, Size& aOutSize, Point& aOutPoint)
+{
+    VirtualDevice* pOldVDev = mpAlphaVDev;
 
-            for( nY = 0L, nOutY = nOffY; nY < nDstHeight; nY++, nOutY++ )
-            {
-                pMapY[ nY ] = aBmpRect.Top() + nOutY * nSrcHeight / nOutHeight;
+    const bool  bHMirr = aOutSize.Width() < 0;
+    const bool  bVMirr = aOutSize.Height() < 0;
 
-                if( bVMirr )
-                    pMapY[ nY ] = nMirrOffY - pMapY[ nY ];
-            }
+    // The scaling in this code path produces really ugly results - it
+    // does the most trivial scaling with no smoothing.
+    GDIMetaFile* pOldMetaFile = mpMetaFile;
+    const bool   bOldMap = mbMap;
 
-            BitmapReadAccess*   pP = ( (Bitmap&) rBmp ).AcquireReadAccess();
-            BitmapReadAccess*   pA = ( (AlphaMask&) rAlpha ).AcquireReadAccess();
+    mpMetaFile = NULL; // fdo#55044 reset before GetBitmap!
+    mbMap = false;
 
-            DBG_ASSERT( pA->GetScanlineFormat() == BMP_FORMAT_8BIT_PAL ||
-                        pA->GetScanlineFormat() == BMP_FORMAT_8BIT_TC_MASK,
-                        "OutputDevice::ImplDrawAlpha(): non-8bit alpha no longer supported!" );
+    Bitmap aBmp(GetBitmap(aDstRect.TopLeft(), aDstRect.GetSize()));
 
-            // #i38887# reading from screen may sometimes fail
-            if( aBmp.ImplGetImpBitmap() )
-            {
-                Bitmap aTmp;
+    // #109044# The generated bitmap need not necessarily be
+    // of aDstRect dimensions, it's internally clipped to
+    // window bounds. Thus, we correct the dest size here,
+    // since we later use it (in nDstWidth/Height) for pixel
+    // access)
+    // #i38887# reading from screen may sometimes fail
+    if (aBmp.ImplGetImpBitmap())
+    {
+        aDstRect.SetSize(aBmp.GetSizePixel());
+    }
 
-                if( mpAlphaVDev )
-                {
-                    aTmp = BlendBitmapWithAlpha(
-                        aBmp,pP,pA,
-                        aDstRect,
-                        nOffY,nDstHeight,
-                        nOffX,nDstWidth,
-                        pMapX.get(),pMapY.get() );
-                }
-                else
-                {
-                    aTmp = BlendBitmap(
-                        aBmp,pP,pA,
-                        nOffY,nDstHeight,
-                        nOffX,nDstWidth,
-                        aBmpRect,aOutSz,
-                        bHMirr,bVMirr,
-                        pMapX.get(),pMapY.get() );
-                }
+    BitmapColor aDstCol;
+    const long nSrcWidth = aBmpRect.GetWidth();
+    const long nSrcHeight = aBmpRect.GetHeight();
 
-                // #110958# Disable alpha VDev, we're doing the necessary
-                // stuff explicitly furher below
-                if( mpAlphaVDev )
-                    mpAlphaVDev = NULL;
+    const long nDstWidth = aDstRect.GetWidth();
+    const long nDstHeight = aDstRect.GetHeight();
 
-                DrawBitmap( aDstRect.TopLeft(),
-                            aTmp );
+    const long nOutWidth = aOutSize.Width();
+    const long nOutHeight = aOutSize.Height();
 
-                // #110958# Enable alpha VDev again
-                mpAlphaVDev = pOldVDev;
-            }
+    // calculate offset in original bitmap
+    // in RTL case this is a little more complicated since the contents of the
+    // bitmap is not mirrored (it never is), however the paint region and bmp region
+    // are in mirrored coordinates, so the intersection of (aOutPt,aOutSz) with these
+    // is content wise somewhere else and needs to take mirroring into account
+    const long nOffX = IsRTLEnabled()
+                            ? aOutSize.Width() - aDstRect.GetWidth() - (aDstRect.Left() - aOutPoint.X())
+                            : aDstRect.Left() - aOutPoint.X();
+
+    const long nOffY = aDstRect.Top() - aOutPoint.Y();
 
-            ( (Bitmap&) rBmp ).ReleaseAccess( pP );
-            ( (AlphaMask&) rAlpha ).ReleaseAccess( pA );
+    long nX, nOutX, nY, nOutY;
+    long nMirrOffX = 0;
+    long nMirrOffY = 0;
 
-            mbMap = bOldMap;
-            mpMetaFile = pOldMetaFile;
+    boost::scoped_array<long> pMapX(new long[nDstWidth]);
+    boost::scoped_array<long> pMapY(new long[nDstHeight]);
+
+    // create horizontal mapping table
+    if (bHMirr)
+    {
+        nMirrOffX = (aBmpRect.Left() << 1) + nSrcWidth - 1;
+    }
+
+    for (nX = 0L, nOutX = nOffX; nX < nDstWidth; nX++, nOutX++)
+    {
+        pMapX[nX] = aBmpRect.Left() + nOutX * nSrcWidth / nOutWidth;
+        if(bHMirr)
+            pMapX[nX] = nMirrOffX - pMapX[nX];
+    }
+
+    // create vertical mapping table
+    if (bVMirr)
+    {
+        nMirrOffY = (aBmpRect.Top() << 1) + nSrcHeight - 1;
+    }
+
+    for(nY = 0L, nOutY = nOffY; nY < nDstHeight; nY++, nOutY++)
+    {
+        pMapY[nY] = aBmpRect.Top() + nOutY * nSrcHeight / nOutHeight;
+
+        if (bVMirr)
+            pMapY[nY] = nMirrOffY - pMapY[nY];
+    }
+
+    Bitmap::ScopedReadAccess pBitmapReadAccess(const_cast<Bitmap&>(rBitmap));
+    AlphaMask::ScopedReadAccess pAlphaReadAccess(const_cast<AlphaMask&>(rAlpha));
+
+    DBG_ASSERT( pAlphaReadAccess->GetScanlineFormat() == BMP_FORMAT_8BIT_PAL ||
+                pAlphaReadAccess->GetScanlineFormat()  == BMP_FORMAT_8BIT_TC_MASK,
+                "OutputDevice::ImplDrawAlpha(): non-8bit alpha no longer supported!" );
+
+    // #i38887# reading from screen may sometimes fail
+    if (aBmp.ImplGetImpBitmap())
+    {
+        Bitmap aNewBitmap;
+
+        if (mpAlphaVDev)
+        {
+            aNewBitmap = BlendBitmapWithAlpha(
+                            aBmp, pBitmapReadAccess.get(), pAlphaReadAccess.get(),
+                            aDstRect,
+                            nOffY, nDstHeight,
+                            nOffX, nDstWidth,
+                            pMapX.get(), pMapY.get() );
         }
+        else
+        {
+            aNewBitmap = BlendBitmap(
+                            aBmp, pBitmapReadAccess.get(), pAlphaReadAccess.get(),
+                            nOffY, nDstHeight,
+                            nOffX, nDstWidth,
+                            aBmpRect, aOutSize,
+                            bHMirr, bVMirr,
+                            pMapX.get(), pMapY.get() );
+        }
+
+        // #110958# Disable alpha VDev, we're doing the necessary
+        // stuff explicitly furher below
+        if (mpAlphaVDev)
+            mpAlphaVDev = NULL;
+
+        DrawBitmap(aDstRect.TopLeft(), aNewBitmap);
+
+        // #110958# Enable alpha VDev again
+        mpAlphaVDev = pOldVDev;
     }
+
+    mbMap = bOldMap;
+    mpMetaFile = pOldMetaFile;
 }
 
 void OutputDevice::ScaleBitmap (Bitmap &rBmp, SalTwoRect &rPosAry)