tdf#130768 speedup huge pixel graphics Cairo

For more information/documentation please
refer to the bugzilla task

Fixed a crash in CppunitTest_desktop_lib which
led to a missing test of mpGraphics in
OutputDevice::DrawTransformedBitmapEx. Other
public methods test that and one of the goals
of the cange was to use that method more often,
so this may have never been detected before

Change-Id: I10e57bd05db0c8cf868ff98d63f5af3d116a3015
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89230
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <Armin.Le.Grand@me.com>

4 files changed, 403 insertions, 134 deletions

diff --git a/vcl/headless/svpbmp.cxx b/vcl/headless/svpbmp.cxx
index 6dd5aeb64bfb..4d881f025d0b 100644
--- a/vcl/headless/svpbmp.cxx
+++ b/vcl/headless/svpbmp.cxx
@@ -34,6 +34,13 @@
 
 using namespace basegfx;
 
+SvpSalBitmap::SvpSalBitmap()
+:   SalBitmap(),
+    basegfx::SystemDependentDataHolder(), // MM02
+    mpDIB()
+{
+}
+
 SvpSalBitmap::~SvpSalBitmap()
 {
     Destroy();
diff --git a/vcl/headless/svpgdi.cxx b/vcl/headless/svpgdi.cxx
index cd59eee1af16..9a2fe936e782 100644
--- a/vcl/headless/svpgdi.cxx
+++ b/vcl/headless/svpgdi.cxx
@@ -323,6 +323,44 @@ namespace
         SourceHelper& operator=(const SourceHelper&) = delete;
     };
 
+    class SystemDependentData_SourceHelper : public basegfx::SystemDependentData
+    {
+    private:
+        std::shared_ptr<SourceHelper>       maSourceHelper;
+
+    public:
+        SystemDependentData_SourceHelper(
+            basegfx::SystemDependentDataManager& rSystemDependentDataManager,
+            const std::shared_ptr<SourceHelper>& rSourceHelper)
+        :   basegfx::SystemDependentData(rSystemDependentDataManager),
+            maSourceHelper(rSourceHelper)
+        {
+        }
+
+        const std::shared_ptr<SourceHelper>& getSourceHelper() const { return maSourceHelper; };
+        virtual sal_Int64 estimateUsageInBytes() const override;
+    };
+
+    // MM02 class to allow buffering of SourceHelper
+    sal_Int64 SystemDependentData_SourceHelper::estimateUsageInBytes() const
+    {
+        sal_Int64 nRetval(0);
+        cairo_surface_t* source(maSourceHelper ? maSourceHelper->getSurface() : nullptr);
+
+        if(source)
+        {
+            const long nStride(cairo_image_surface_get_stride(source));
+            const long nHeight(cairo_image_surface_get_height(source));
+
+            if(0 != nStride && 0 != nHeight)
+            {
+                nRetval = nStride * nHeight;
+            }
+        }
+
+        return nRetval;
+    }
+
     class MaskHelper
     {
     public:
@@ -388,6 +426,123 @@ namespace
         MaskHelper(const MaskHelper&) = delete;
         MaskHelper& operator=(const MaskHelper&) = delete;
     };
+
+    class SystemDependentData_MaskHelper : public basegfx::SystemDependentData
+    {
+    private:
+        std::shared_ptr<MaskHelper>       maMaskHelper;
+
+    public:
+        SystemDependentData_MaskHelper(
+            basegfx::SystemDependentDataManager& rSystemDependentDataManager,
+            const std::shared_ptr<MaskHelper>& rMaskHelper)
+        :   basegfx::SystemDependentData(rSystemDependentDataManager),
+            maMaskHelper(rMaskHelper)
+        {
+        }
+
+        const std::shared_ptr<MaskHelper>& getMaskHelper() const { return maMaskHelper; };
+        virtual sal_Int64 estimateUsageInBytes() const override;
+    };
+
+    // MM02 class to allow buffering of MaskHelper
+    sal_Int64 SystemDependentData_MaskHelper::estimateUsageInBytes() const
+    {
+        sal_Int64 nRetval(0);
+        cairo_surface_t* mask(maMaskHelper ? maMaskHelper->getMask() : nullptr);
+
+        if(mask)
+        {
+            const long nStride(cairo_image_surface_get_stride(mask));
+            const long nHeight(cairo_image_surface_get_height(mask));
+
+            if(0 != nStride && 0 != nHeight)
+            {
+                nRetval = nStride * nHeight;
+            }
+        }
+
+        return nRetval;
+    }
+
+    // MM02 decide to use buffers or not
+    static const char* pDisableMM02Goodies(getenv("SAL_DISABLE_MM02_GOODIES"));
+    static bool bUseBuffer(nullptr == pDisableMM02Goodies);
+    static long nMinimalSquareSizeToBuffer(64*64);
+
+    void tryToUseSourceBuffer(
+        const SalBitmap& rSourceBitmap,
+        std::shared_ptr<SourceHelper>& rSurface)
+    {
+        // MM02 try to access buffered SourceHelper
+        std::shared_ptr<SystemDependentData_SourceHelper> pSystemDependentData_SourceHelper;
+        const bool bBufferSource(bUseBuffer
+            && rSourceBitmap.GetSize().Width() * rSourceBitmap.GetSize().Height() > nMinimalSquareSizeToBuffer);
+
+        if(bBufferSource)
+        {
+            const SvpSalBitmap& rSrcBmp(static_cast<const SvpSalBitmap&>(rSourceBitmap));
+            pSystemDependentData_SourceHelper = rSrcBmp.getSystemDependentData<SystemDependentData_SourceHelper>();
+
+            if(pSystemDependentData_SourceHelper)
+            {
+                // reuse buffered data
+                rSurface = pSystemDependentData_SourceHelper->getSourceHelper();
+            }
+        }
+
+        if(!rSurface)
+        {
+            // create data on-demand
+            rSurface = std::make_shared<SourceHelper>(rSourceBitmap);
+
+            if(bBufferSource)
+            {
+                // add to buffering mechanism to potentially reuse next time
+                const SvpSalBitmap& rSrcBmp(static_cast<const SvpSalBitmap&>(rSourceBitmap));
+                rSrcBmp.addOrReplaceSystemDependentData<SystemDependentData_SourceHelper>(
+                    ImplGetSystemDependentDataManager(),
+                    rSurface);
+            }
+        }
+    }
+
+    void tryToUseMaskBuffer(
+        const SalBitmap& rMaskBitmap,
+        std::shared_ptr<MaskHelper>& rMask)
+    {
+        // MM02 try to access buffered MaskHelper
+        std::shared_ptr<SystemDependentData_MaskHelper> pSystemDependentData_MaskHelper;
+        const bool bBufferMask(bUseBuffer
+            && rMaskBitmap.GetSize().Width() * rMaskBitmap.GetSize().Height() > nMinimalSquareSizeToBuffer);
+
+        if(bBufferMask)
+        {
+            const SvpSalBitmap& rSrcBmp(static_cast<const SvpSalBitmap&>(rMaskBitmap));
+            pSystemDependentData_MaskHelper = rSrcBmp.getSystemDependentData<SystemDependentData_MaskHelper>();
+
+            if(pSystemDependentData_MaskHelper)
+            {
+                // reuse buffered data
+                rMask = pSystemDependentData_MaskHelper->getMaskHelper();
+            }
+        }
+
+        if(!rMask)
+        {
+            // create data on-demand
+            rMask = std::make_shared<MaskHelper>(rMaskBitmap);
+
+            if(bBufferMask)
+            {
+                // add to buffering mechanism to potentially reuse next time
+                const SvpSalBitmap& rSrcBmp(static_cast<const SvpSalBitmap&>(rMaskBitmap));
+                rSrcBmp.addOrReplaceSystemDependentData<SystemDependentData_MaskHelper>(
+                    ImplGetSystemDependentDataManager(),
+                    rMask);
+            }
+        }
+    }
 }
 
 bool SvpSalGraphics::drawAlphaBitmap( const SalTwoRect& rTR, const SalBitmap& rSourceBitmap, const SalBitmap& rAlphaBitmap )
@@ -398,16 +553,22 @@ bool SvpSalGraphics::drawAlphaBitmap( const SalTwoRect& rTR, const SalBitmap& rS
         return false;
     }
 
-    SourceHelper aSurface(rSourceBitmap);
-    cairo_surface_t* source = aSurface.getSurface();
+    // MM02 try to access buffered SourceHelper
+    std::shared_ptr<SourceHelper> aSurface;
+    tryToUseSourceBuffer(rSourceBitmap, aSurface);
+    cairo_surface_t* source = aSurface->getSurface();
+
     if (!source)
     {
         SAL_WARN("vcl.gdi", "unsupported SvpSalGraphics::drawAlphaBitmap case");
         return false;
     }
 
-    MaskHelper aMask(rAlphaBitmap);
-    cairo_surface_t *mask = aMask.getMask();
+    // MM02 try to access buffered MaskHelper
+    std::shared_ptr<MaskHelper> aMask;
+    tryToUseMaskBuffer(rAlphaBitmap, aMask);
+    cairo_surface_t *mask = aMask->getMask();
+
     if (!mask)
     {
         SAL_WARN("vcl.gdi", "unsupported SvpSalGraphics::drawAlphaBitmap case");
@@ -468,29 +629,34 @@ bool SvpSalGraphics::drawTransformedBitmap(
         return false;
     }
 
-    SourceHelper aSurface(rSourceBitmap);
-    cairo_surface_t* source = aSurface.getSurface();
-    if (!source)
+    // MM02 try to access buffered SourceHelper
+    std::shared_ptr<SourceHelper> aSurface;
+    tryToUseSourceBuffer(rSourceBitmap, aSurface);
+    cairo_surface_t* source(aSurface->getSurface());
+
+    if(!source)
     {
         SAL_WARN("vcl.gdi", "unsupported SvpSalGraphics::drawTransformedBitmap case");
         return false;
     }
 
-    std::unique_ptr<MaskHelper> xMask;
-    cairo_surface_t *mask = nullptr;
-    if (pAlphaBitmap)
+    // MM02 try to access buffered MaskHelper
+    std::shared_ptr<MaskHelper> aMask;
+
+    if(nullptr != pAlphaBitmap)
     {
-        xMask.reset(new MaskHelper(*pAlphaBitmap));
-        mask = xMask->getMask();
-        if (!mask)
-        {
-            SAL_WARN("vcl.gdi", "unsupported SvpSalGraphics::drawTransformedBitmap case");
-            return false;
-        }
+        tryToUseMaskBuffer(*pAlphaBitmap, aMask);
     }
 
-    const Size aSize = rSourceBitmap.GetSize();
+    // access cairo_surface_t from MaskHelper
+    cairo_surface_t* mask(aMask ? aMask->getMask() : nullptr);
+    if(nullptr != pAlphaBitmap && nullptr == mask)
+    {
+        SAL_WARN("vcl.gdi", "unsupported SvpSalGraphics::drawTransformedBitmap case");
+        return false;
+    }
 
+    const Size aSize = rSourceBitmap.GetSize();
     cairo_t* cr = getCairoContext(false);
     clipRegion(cr);
 
@@ -1761,8 +1927,17 @@ void SvpSalGraphics::copyBits( const SalTwoRect& rTR,
 
 void SvpSalGraphics::drawBitmap(const SalTwoRect& rTR, const SalBitmap& rSourceBitmap)
 {
-    SourceHelper aSurface(rSourceBitmap);
-    cairo_surface_t* source = aSurface.getSurface();
+    // MM02 try to access buffered SourceHelper
+    std::shared_ptr<SourceHelper> aSurface;
+    tryToUseSourceBuffer(rSourceBitmap, aSurface);
+    cairo_surface_t* source = aSurface->getSurface();
+
+    if (!source)
+    {
+        SAL_WARN("vcl.gdi", "unsupported SvpSalGraphics::drawAlphaBitmap case");
+        return;
+    }
+
     copyWithOperator(rTR, source, CAIRO_OPERATOR_OVER);
 }
 
@@ -1786,6 +1961,10 @@ void SvpSalGraphics::drawMask( const SalTwoRect& rTR,
 {
     /** creates an image from the given rectangle, replacing all black pixels
      *  with nMaskColor and make all other full transparent */
+    // MM02 here decided *against* using buffered SourceHelper
+    // because the data gets somehow 'unmuliplied'. This may also be
+    // done just once, but I am not sure if this is safe to do.
+    // So for now dispense re-using data here.
     SourceHelper aSurface(rSalBitmap, true); // The mask is argb32
     if (!aSurface.getSurface())
     {
diff --git a/vcl/inc/headless/svpbmp.hxx b/vcl/inc/headless/svpbmp.hxx
index 7f79dda8e9bc..1551fc844a82 100644
--- a/vcl/inc/headless/svpbmp.hxx
+++ b/vcl/inc/headless/svpbmp.hxx
@@ -23,11 +23,13 @@
 #include <sal/config.h>
 
 #include <salbmp.hxx>
+#include <basegfx/utils/systemdependentdata.hxx>
 
-class VCL_DLLPUBLIC SvpSalBitmap final : public SalBitmap
+class VCL_DLLPUBLIC SvpSalBitmap final : public SalBitmap, public basegfx::SystemDependentDataHolder // MM02
 {
     std::unique_ptr<BitmapBuffer> mpDIB;
 public:
+             SvpSalBitmap();
     virtual ~SvpSalBitmap() override;
 
     // SalBitmap
@@ -58,6 +60,28 @@ public:
     virtual bool            ScalingSupported() const override;
     virtual bool            Scale( const double& rScaleX, const double& rScaleY, BmpScaleFlag nScaleFlag ) override;
     virtual bool            Replace( const Color& rSearchColor, const Color& rReplaceColor, sal_uInt8 nTol ) override;
+
+    // MM02 exclusive management op's for SystemDependentData at WinSalBitmap
+    template<class T>
+    std::shared_ptr<T> getSystemDependentData() const
+    {
+        return std::static_pointer_cast<T>(basegfx::SystemDependentDataHolder::getSystemDependentData(typeid(T).hash_code()));
+    }
+
+    template<class T, class... Args>
+    std::shared_ptr<T> addOrReplaceSystemDependentData(basegfx::SystemDependentDataManager& manager, Args&&... args) const
+    {
+        std::shared_ptr<T> r = std::make_shared<T>(manager, std::forward<Args>(args)...);
+
+        // tdf#129845 only add to buffer if a relevant buffer time is estimated
+        if(r->calculateCombinedHoldCyclesInSeconds() > 0)
+        {
+            basegfx::SystemDependentData_SharedPtr r2(r);
+            const_cast< SvpSalBitmap* >(this)->basegfx::SystemDependentDataHolder::addOrReplaceSystemDependentData(r2);
+        }
+
+        return r;
+    }
 };
 
 #endif // INCLUDED_VCL_INC_HEADLESS_SVPBMP_HXX
diff --git a/vcl/source/outdev/bitmap.cxx b/vcl/source/outdev/bitmap.cxx
index 7ab069c2f443..9821fa0aade5 100644
--- a/vcl/source/outdev/bitmap.cxx
+++ b/vcl/source/outdev/bitmap.cxx
@@ -1157,6 +1157,32 @@ bool OutputDevice::TransformAndReduceBitmapExToTargetRange(
     return true;
 }
 
+// MM02 add som etest class to get a simple timer-based output to be able
+// to check if it gets faster - and how much. Uncomment next line or set
+// DO_TIME_TEST for compile tiome if you want to use it
+// #define DO_TIME_TEST
+#ifdef DO_TIME_TEST
+#include <tools/time.hxx>
+struct LocalTimeTest
+{
+    const sal_uInt64 nStartTime;
+    LocalTimeTest() : nStartTime(tools::Time::GetSystemTicks()) {}
+    ~LocalTimeTest()
+    {
+        const sal_uInt64 nEndTime(tools::Time::GetSystemTicks());
+        const sal_uInt64 nDiffTime(nEndTime - nStartTime);
+
+        if(nDiffTime > 0)
+        {
+            OStringBuffer aOutput("Time: ");
+            OString aNumber(OString::number(nDiffTime));
+            aOutput.append(aNumber);
+            OSL_FAIL(aOutput.getStr());
+        }
+    }
+};
+#endif
+
 void OutputDevice::DrawTransformedBitmapEx(
     const basegfx::B2DHomMatrix& rTransformation,
     const BitmapEx& rBitmapEx)
@@ -1169,6 +1195,42 @@ void OutputDevice::DrawTransformedBitmapEx(
     if(rBitmapEx.IsEmpty())
         return;
 
+    // MM02 compared to other public methods of OutputDevice
+    // this test was missing and led to zero-ptr-accesses
+    if ( !mpGraphics && !AcquireGraphics() )
+        return;
+
+#ifdef DO_TIME_TEST
+    // MM02 start time test when some data (not for trivial stuff). Will
+    // trigger and show data when leaving this method by destructing helper
+    static const char* pEnableBitmapDrawTimerTimer(getenv("SAL_ENABLE_TIMER_BITMAPDRAW"));
+    static bool bUseTimer(nullptr != pEnableBitmapDrawTimerTimer);
+    std::unique_ptr<LocalTimeTest> aTimeTest(
+        bUseTimer && rBitmapEx.GetSizeBytes() > 10000
+        ? new LocalTimeTest()
+        : nullptr);
+#endif
+
+    // MM02 reorganize order: Prefer DrawTransformBitmapExDirect due
+    // to this having evolved and is improved on quite some systems.
+    // Check for exclusion parameters that may prevent using it
+    static bool bAllowPreferDirectPaint(true);
+    const bool bInvert(RasterOp::Invert == meRasterOp);
+    const bool bBitmapChangedColor(mnDrawMode & (DrawModeFlags::BlackBitmap | DrawModeFlags::WhiteBitmap | DrawModeFlags::GrayBitmap ));
+    const bool bMetafile(nullptr != mpMetaFile);
+    const bool bTryDirectPaint(!bInvert && !bBitmapChangedColor && !bMetafile);
+
+    if(bAllowPreferDirectPaint && bTryDirectPaint)
+    {
+        const basegfx::B2DHomMatrix aFullTransform(GetViewTransformation() * rTransformation);
+
+        if(DrawTransformBitmapExDirect(aFullTransform, rBitmapEx))
+        {
+            // we are done
+            return;
+        }
+    }
+
     // decompose matrix to check rotation and shear
     basegfx::B2DVector aScale, aTranslate;
     double fRotate, fShearX;
@@ -1178,8 +1240,6 @@ void OutputDevice::DrawTransformedBitmapEx(
     const bool bMirroredX(basegfx::fTools::less(aScale.getX(), 0.0));
     const bool bMirroredY(basegfx::fTools::less(aScale.getY(), 0.0));
 
-    const bool bMetafile = mpMetaFile != nullptr;
-
     if(!bRotated && !bSheared && !bMirroredX && !bMirroredY)
     {
         // with no rotation, shear or mirroring it can be mapped to DrawBitmapEx
@@ -1205,139 +1265,138 @@ void OutputDevice::DrawTransformedBitmapEx(
         return;
     }
 
-    // we have rotation,shear or mirror, check if some crazy mode needs the
-    // created transformed bitmap
-    const bool bInvert(RasterOp::Invert == meRasterOp);
-    const bool bBitmapChangedColor(mnDrawMode & (DrawModeFlags::BlackBitmap | DrawModeFlags::WhiteBitmap | DrawModeFlags::GrayBitmap ));
-    bool bDone(false);
-    basegfx::B2DHomMatrix aFullTransform(GetViewTransformation() * rTransformation);
-    const bool bTryDirectPaint(!bInvert && !bBitmapChangedColor && !bMetafile );
-
+    // MM02 bAllowPreferDirectPaint may have been false to allow
+    // to specify order of executions, so give bTryDirectPaint a call
     if(bTryDirectPaint)
     {
-        bDone = DrawTransformBitmapExDirect(aFullTransform, rBitmapEx);
-    }
+        const basegfx::B2DHomMatrix aFullTransform(GetViewTransformation() * rTransformation);
 
-    if(!bDone)
-    {
-        // take the fallback when no rotate and shear, but mirror (else we would have done this above)
-        if(!bRotated && !bSheared)
+        if(DrawTransformBitmapExDirect(aFullTransform, rBitmapEx))
         {
-            // with no rotation or shear it can be mapped to DrawBitmapEx
-            // do *not* execute the mirroring here, it's done in the fallback
-            // #i124580# the correct DestSize needs to be calculated based on MaxXY values
-            const Point aDestPt(basegfx::fround(aTranslate.getX()), basegfx::fround(aTranslate.getY()));
-            const Size aDestSize(
-                basegfx::fround(aScale.getX() + aTranslate.getX()) - aDestPt.X(),
-                basegfx::fround(aScale.getY() + aTranslate.getY()) - aDestPt.Y());
-
-            DrawBitmapEx(aDestPt, aDestSize, rBitmapEx);
+            // we are done
             return;
         }
+    }
+
+    // take the fallback when no rotate and shear, but mirror (else we would have done this above)
+    if(!bRotated && !bSheared)
+    {
+        // with no rotation or shear it can be mapped to DrawBitmapEx
+        // do *not* execute the mirroring here, it's done in the fallback
+        // #i124580# the correct DestSize needs to be calculated based on MaxXY values
+        const Point aDestPt(basegfx::fround(aTranslate.getX()), basegfx::fround(aTranslate.getY()));
+        const Size aDestSize(
+            basegfx::fround(aScale.getX() + aTranslate.getX()) - aDestPt.X(),
+            basegfx::fround(aScale.getY() + aTranslate.getY()) - aDestPt.Y());
 
-        assert(bSheared || bRotated); // at this point we are either sheared or rotated or both
+        DrawBitmapEx(aDestPt, aDestSize, rBitmapEx);
+        return;
+    }
 
-        // fallback; create transformed bitmap the hard way (back-transform
-        // the pixels) and paint
-        basegfx::B2DRange aVisibleRange(0.0, 0.0, 1.0, 1.0);
+    // at this point we are either sheared or rotated or both
+    assert(bSheared || bRotated);
+
+    // fallback; create transformed bitmap the hard way (back-transform
+    // the pixels) and paint
+    basegfx::B2DRange aVisibleRange(0.0, 0.0, 1.0, 1.0);
+
+    // limit maximum area to something looking good for non-pixel-based targets (metafile, printer)
+    // by using a fixed minimum (allow at least, but no need to utilize) for good smoothing and an area
+    // dependent of original size for good quality when e.g. rotated/sheared. Still, limit to a maximum
+    // to avoid crashes/resource problems (ca. 1500x3000 here)
+    const Size& rOriginalSizePixel(rBitmapEx.GetSizePixel());
+    const double fOrigArea(rOriginalSizePixel.Width() * rOriginalSizePixel.Height() * 0.5);
+    const double fOrigAreaScaled(fOrigArea * 1.44);
+    double fMaximumArea(std::min(4500000.0, std::max(1000000.0, fOrigAreaScaled)));
+    basegfx::B2DHomMatrix aFullTransform(GetViewTransformation() * rTransformation);
 
-        // limit maximum area to something looking good for non-pixel-based targets (metafile, printer)
-        // by using a fixed minimum (allow at least, but no need to utilize) for good smoothing and an area
-        // dependent of original size for good quality when e.g. rotated/sheared. Still, limit to a maximum
-        // to avoid crashes/resource problems (ca. 1500x3000 here)
-        const Size& rOriginalSizePixel(rBitmapEx.GetSizePixel());
-        const double fOrigArea(rOriginalSizePixel.Width() * rOriginalSizePixel.Height() * 0.5);
-        const double fOrigAreaScaled(fOrigArea * 1.44);
-        double fMaximumArea(std::min(4500000.0, std::max(1000000.0, fOrigAreaScaled)));
+    if(!bMetafile)
+    {
+        if ( !TransformAndReduceBitmapExToTargetRange( aFullTransform, aVisibleRange, fMaximumArea ) )
+            return;
+    }
 
-        if(!bMetafile)
-        {
-            if ( !TransformAndReduceBitmapExToTargetRange( aFullTransform, aVisibleRange, fMaximumArea ) )
-                return;
-        }
+    if(!aVisibleRange.isEmpty())
+    {
+        BitmapEx aTransformed(rBitmapEx);
 
-        if(!aVisibleRange.isEmpty())
+        // #122923# when the result needs an alpha channel due to being rotated or sheared
+        // and thus uncovering areas, add these channels so that the own transformer (used
+        // in getTransformed) also creates a transformed alpha channel
+        if(!aTransformed.IsTransparent() && (bSheared || bRotated))
         {
-            BitmapEx aTransformed(rBitmapEx);
+            // parts will be uncovered, extend aTransformed with a mask bitmap
+            const Bitmap aContent(aTransformed.GetBitmap());
 
-            // #122923# when the result needs an alpha channel due to being rotated or sheared
-            // and thus uncovering areas, add these channels so that the own transformer (used
-            // in getTransformed) also creates a transformed alpha channel
-            if(!aTransformed.IsTransparent() && (bSheared || bRotated))
-            {
-                // parts will be uncovered, extend aTransformed with a mask bitmap
-                const Bitmap aContent(aTransformed.GetBitmap());
-
-                AlphaMask aMaskBmp(aContent.GetSizePixel());
-                aMaskBmp.Erase(0);
+            AlphaMask aMaskBmp(aContent.GetSizePixel());
+            aMaskBmp.Erase(0);
 
-                aTransformed = BitmapEx(aContent, aMaskBmp);
-            }
+            aTransformed = BitmapEx(aContent, aMaskBmp);
+        }
 
-            // Remove scaling from aFulltransform: we transform due to shearing or rotation, scaling
-            // will happen according to aDestSize.
-            basegfx::B2DVector aFullScale, aFullTranslate;
-            double fFullRotate, fFullShearX;
-            aFullTransform.decompose(aFullScale, aFullTranslate, fFullRotate, fFullShearX);
-            // Require positive scaling, negative scaling would loose horizontal or vertical flip.
-            if (aFullScale.getX() > 0 && aFullScale.getY() > 0)
-            {
-                basegfx::B2DHomMatrix aTransform = basegfx::utils::createScaleB2DHomMatrix(
-                    rOriginalSizePixel.getWidth() / aFullScale.getX(),
-                    rOriginalSizePixel.getHeight() / aFullScale.getY());
-                aFullTransform *= aTransform;
-            }
+        // Remove scaling from aFulltransform: we transform due to shearing or rotation, scaling
+        // will happen according to aDestSize.
+        basegfx::B2DVector aFullScale, aFullTranslate;
+        double fFullRotate, fFullShearX;
+        aFullTransform.decompose(aFullScale, aFullTranslate, fFullRotate, fFullShearX);
+        // Require positive scaling, negative scaling would loose horizontal or vertical flip.
+        if (aFullScale.getX() > 0 && aFullScale.getY() > 0)
+        {
+            basegfx::B2DHomMatrix aTransform = basegfx::utils::createScaleB2DHomMatrix(
+                rOriginalSizePixel.getWidth() / aFullScale.getX(),
+                rOriginalSizePixel.getHeight() / aFullScale.getY());
+            aFullTransform *= aTransform;
+        }
 
-            double fSourceRatio = 1.0;
-            if (rOriginalSizePixel.getHeight() != 0)
-            {
-                fSourceRatio = rOriginalSizePixel.getWidth() / rOriginalSizePixel.getHeight();
-            }
-            double fTargetRatio = 1.0;
-            if (aFullScale.getY() != 0)
-            {
-                fTargetRatio = aFullScale.getX() / aFullScale.getY();
-            }
-            bool bAspectRatioKept = rtl::math::approxEqual(fSourceRatio, fTargetRatio);
-            if (bSheared || !bAspectRatioKept)
-            {
-                // Not only rotation, or scaling does not keep aspect ratio.
-                aTransformed = aTransformed.getTransformed(
-                    aFullTransform,
-                    aVisibleRange,
-                    fMaximumArea);
-            }
-            else
+        double fSourceRatio = 1.0;
+        if (rOriginalSizePixel.getHeight() != 0)
+        {
+            fSourceRatio = rOriginalSizePixel.getWidth() / rOriginalSizePixel.getHeight();
+        }
+        double fTargetRatio = 1.0;
+        if (aFullScale.getY() != 0)
+        {
+            fTargetRatio = aFullScale.getX() / aFullScale.getY();
+        }
+        bool bAspectRatioKept = rtl::math::approxEqual(fSourceRatio, fTargetRatio);
+        if (bSheared || !bAspectRatioKept)
+        {
+            // Not only rotation, or scaling does not keep aspect ratio.
+            aTransformed = aTransformed.getTransformed(
+                aFullTransform,
+                aVisibleRange,
+                fMaximumArea);
+        }
+        else
+        {
+            // Just rotation, can do that directly.
+            fFullRotate = fmod(fFullRotate * -1, F_2PI);
+            if (fFullRotate < 0)
             {
-                // Just rotation, can do that directly.
-                fFullRotate = fmod(fFullRotate * -1, F_2PI);
-                if (fFullRotate < 0)
-                {
-                    fFullRotate += F_2PI;
-                }
-                long nAngle10 = basegfx::fround(basegfx::rad2deg(fFullRotate) * 10);
-                aTransformed.Rotate(nAngle10, COL_TRANSPARENT);
+                fFullRotate += F_2PI;
             }
-            basegfx::B2DRange aTargetRange(0.0, 0.0, 1.0, 1.0);
+            long nAngle10 = basegfx::fround(basegfx::rad2deg(fFullRotate) * 10);
+            aTransformed.Rotate(nAngle10, COL_TRANSPARENT);
+        }
+        basegfx::B2DRange aTargetRange(0.0, 0.0, 1.0, 1.0);
 
-            // get logic object target range
-            aTargetRange.transform(rTransformation);
+        // get logic object target range
+        aTargetRange.transform(rTransformation);
 
-            // get from unified/relative VisibleRange to logoc one
-            aVisibleRange.transform(
-                basegfx::utils::createScaleTranslateB2DHomMatrix(
-                    aTargetRange.getRange(),
-                    aTargetRange.getMinimum()));
+        // get from unified/relative VisibleRange to logoc one
+        aVisibleRange.transform(
+            basegfx::utils::createScaleTranslateB2DHomMatrix(
+                aTargetRange.getRange(),
+                aTargetRange.getMinimum()));
 
-            // extract point and size; do not remove size, the bitmap may have been prepared reduced by purpose
-            // #i124580# the correct DestSize needs to be calculated based on MaxXY values
-            const Point aDestPt(basegfx::fround(aVisibleRange.getMinX()), basegfx::fround(aVisibleRange.getMinY()));
-            const Size aDestSize(
-                basegfx::fround(aVisibleRange.getMaxX()) - aDestPt.X(),
-                basegfx::fround(aVisibleRange.getMaxY()) - aDestPt.Y());
+        // extract point and size; do not remove size, the bitmap may have been prepared reduced by purpose
+        // #i124580# the correct DestSize needs to be calculated based on MaxXY values
+        const Point aDestPt(basegfx::fround(aVisibleRange.getMinX()), basegfx::fround(aVisibleRange.getMinY()));
+        const Size aDestSize(
+            basegfx::fround(aVisibleRange.getMaxX()) - aDestPt.X(),
+            basegfx::fround(aVisibleRange.getMaxY()) - aDestPt.Y());
 
-            DrawBitmapEx(aDestPt, aDestSize, aTransformed);
-        }
+        DrawBitmapEx(aDestPt, aDestSize, aTransformed);
     }
 }