Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 661 insertions, 0 deletions

diff --git a/canvas/source/vcl/spritecanvashelper.cxx b/canvas/source/vcl/spritecanvashelper.cxx
new file mode 100644
index 000000000..2eb622431
--- /dev/null
+++ b/canvas/source/vcl/spritecanvashelper.cxx
@@ -0,0 +1,661 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <sal/config.h>
+#include <sal/log.hxx>
+
+#include <boost/cast.hpp>
+
+#include <basegfx/range/b2drectangle.hxx>
+#include <rtl/math.hxx>
+#include <tools/diagnose_ex.h>
+#include <vcl/canvastools.hxx>
+#include <vcl/outdev.hxx>
+#include <vcl/window.hxx>
+
+#include <canvas/canvastools.hxx>
+
+#include "canvascustomsprite.hxx"
+#include "spritecanvashelper.hxx"
+#include "spritecanvas.hxx"
+
+using namespace ::com::sun::star;
+
+#define FPS_BOUNDS ::tools::Rectangle(0,0,130,90)
+#define INFO_COLOR COL_RED
+
+namespace vclcanvas
+{
+    namespace
+    {
+        /** Sprite redraw at original position
+
+            Used to repaint the whole canvas (background and all
+            sprites)
+         */
+        void spriteRedraw( OutputDevice&                      rOutDev,
+                           const ::canvas::Sprite::Reference& rSprite )
+        {
+            // downcast to derived vclcanvas::Sprite interface, which
+            // provides the actual redraw methods.
+            ::boost::polymorphic_downcast< Sprite* >(rSprite.get())->redraw(rOutDev,
+                                                                            true);
+        }
+
+        double calcNumPixel( const ::canvas::Sprite::Reference& rSprite )
+        {
+            const ::basegfx::B2DSize& rSize(
+                ::boost::polymorphic_downcast< Sprite* >(rSprite.get())->getSizePixel() );
+
+            return rSize.getX() * rSize.getY();
+        }
+
+        void repaintBackground( OutputDevice&               rOutDev,
+                                OutputDevice const &        rBackBuffer,
+                                const ::basegfx::B2DRange&  rArea )
+        {
+            const ::Point& rPos( vcl::unotools::pointFromB2DPoint( rArea.getMinimum()) );
+            const ::Size& rSize( vcl::unotools::sizeFromB2DSize( rArea.getRange()) );
+
+            rOutDev.DrawOutDev( rPos, rSize, rPos, rSize, rBackBuffer );
+        }
+
+        void opaqueUpdateSpriteArea( const ::canvas::Sprite::Reference& rSprite,
+                                     OutputDevice&                      rOutDev,
+                                     const ::basegfx::B2IRange&         rArea )
+        {
+            const ::tools::Rectangle& rRequestedArea(
+                vcl::unotools::rectangleFromB2IRectangle( rArea ) );
+
+            // clip output to actual update region (otherwise a)
+            // wouldn't save much render time, and b) will clutter
+            // scrolled sprite content outside this area)
+            rOutDev.EnableMapMode( false );
+            rOutDev.SetAntialiasing( AntialiasingFlags::Enable );
+            rOutDev.SetClipRegion(vcl::Region(rRequestedArea));
+
+            // repaint affected sprite directly to output device (at
+            // the actual screen output position)
+            ::boost::polymorphic_downcast< Sprite* >(
+                rSprite.get() )->redraw( rOutDev,
+                                         false ); // rendering
+                                                  // directly to
+                                                  // frontbuffer
+        }
+
+        void renderInfoText( OutputDevice&          rOutDev,
+                             const OUString& rStr,
+                             const Point&           rPos )
+        {
+            vcl::Font aVCLFont;
+            aVCLFont.SetFontHeight( 20 );
+            aVCLFont.SetColor( INFO_COLOR );
+
+            rOutDev.SetTextAlign(ALIGN_TOP);
+            rOutDev.SetTextColor( INFO_COLOR );
+            rOutDev.SetFont( aVCLFont );
+
+            rOutDev.DrawText( rPos, rStr );
+        }
+
+    }
+
+    SpriteCanvasHelper::SpriteCanvasHelper() :
+        mpRedrawManager( nullptr ),
+        mpOwningSpriteCanvas( nullptr ),
+        maVDev(VclPtr<VirtualDevice>::Create()),
+        mbShowFrameInfo( false ),
+        mbShowSpriteBounds( false ),
+        mbIsUnsafeScrolling( false )
+    {
+#if OSL_DEBUG_LEVEL > 0
+        // inverse defaults for verbose debug mode
+        mbShowFrameInfo = true;
+        // this looks like drawing errors, enable only if explicitly asked for
+        static bool enableShowSpriteBounds = getenv("CANVAS_SPRITE_BOUNDS") != nullptr;
+        mbShowSpriteBounds = enableShowSpriteBounds;
+#endif
+    }
+
+    SpriteCanvasHelper::~SpriteCanvasHelper()
+    {
+        SolarMutexGuard aGuard;
+        maVDev.disposeAndClear();
+    }
+
+    void SpriteCanvasHelper::init( const OutDevProviderSharedPtr& rOutDev,
+                                   SpriteCanvas&                  rOwningSpriteCanvas,
+                                   ::canvas::SpriteRedrawManager& rManager,
+                                   bool                           bProtect,
+                                   bool                           bHaveAlpha )
+    {
+        mpOwningSpriteCanvas = &rOwningSpriteCanvas;
+        mpRedrawManager = &rManager;
+
+        CanvasHelper::init(rOwningSpriteCanvas,rOutDev,bProtect,bHaveAlpha);
+    }
+
+    void SpriteCanvasHelper::disposing()
+    {
+        mpRedrawManager = nullptr;
+        mpOwningSpriteCanvas = nullptr;
+
+        // forward to base
+        CanvasHelper::disposing();
+    }
+
+    uno::Reference< rendering::XAnimatedSprite > SpriteCanvasHelper::createSpriteFromAnimation(
+        const uno::Reference< rendering::XAnimation >&  )
+    {
+        return uno::Reference< rendering::XAnimatedSprite >();
+    }
+
+    uno::Reference< rendering::XAnimatedSprite > SpriteCanvasHelper::createSpriteFromBitmaps(
+        const uno::Sequence< uno::Reference< rendering::XBitmap > >& ,
+        sal_Int8                                                      )
+    {
+        return uno::Reference< rendering::XAnimatedSprite >();
+    }
+
+    uno::Reference< rendering::XCustomSprite > SpriteCanvasHelper::createCustomSprite( const geometry::RealSize2D& spriteSize )
+    {
+        if( !mpRedrawManager || !mpDevice )
+            return uno::Reference< rendering::XCustomSprite >(); // we're disposed
+
+        return uno::Reference< rendering::XCustomSprite >(
+            new CanvasCustomSprite( spriteSize,
+                                    *mpDevice,
+                                    mpOwningSpriteCanvas,
+                                    mpOwningSpriteCanvas->getFrontBuffer(),
+                                    mbShowSpriteBounds ) );
+    }
+
+    uno::Reference< rendering::XSprite > SpriteCanvasHelper::createClonedSprite( const uno::Reference< rendering::XSprite >&  )
+    {
+        return uno::Reference< rendering::XSprite >();
+    }
+
+    bool SpriteCanvasHelper::updateScreen( bool bUpdateAll,
+                                           bool&    io_bSurfaceDirty )
+    {
+        if( !mpRedrawManager ||
+            !mpOwningSpriteCanvas ||
+            !mpOwningSpriteCanvas->getFrontBuffer() ||
+            !mpOwningSpriteCanvas->getBackBuffer() )
+        {
+            return false; // disposed, or otherwise dysfunctional
+        }
+
+        // commit to backbuffer
+        flush();
+
+        OutputDevice&       rOutDev( mpOwningSpriteCanvas->getFrontBuffer()->getOutDev() );
+        BackBufferSharedPtr pBackBuffer( mpOwningSpriteCanvas->getBackBuffer() );
+        OutputDevice&       rBackOutDev( pBackBuffer->getOutDev() );
+
+        // actual OutputDevice is a shared resource - restore its
+        // state when done.
+        tools::OutDevStateKeeper aStateKeeper( rOutDev );
+
+        const Size  aOutDevSize( rBackOutDev.GetOutputSizePixel() );
+        const Point aEmptyPoint(0,0);
+
+        vcl::Window* pTargetWindow = nullptr;
+        if( rOutDev.GetOutDevType() == OUTDEV_WINDOW )
+        {
+            pTargetWindow = rOutDev.GetOwnerWindow(); // TODO(Q3): Evil downcast.
+
+            // we're double-buffered, thus no need for paint area-limiting
+            // clips. besides that, will interfere with animations (as for
+            // Window-invalidate repaints, only parts of the window will
+            // be redrawn otherwise)
+            const vcl::Region aFullWindowRegion( ::tools::Rectangle(aEmptyPoint,
+                                                      aOutDevSize) );
+            pTargetWindow->ExpandPaintClipRegion(aFullWindowRegion);
+        }
+
+        // TODO(P1): Might be worthwhile to track areas of background
+        // changes, too.
+        if( !bUpdateAll && !io_bSurfaceDirty )
+        {
+            if( mbShowFrameInfo )
+            {
+                // also repaint background below frame counter (fake
+                // that as a sprite vanishing in this area)
+                mpRedrawManager->updateSprite( ::canvas::Sprite::Reference(),
+                                               ::basegfx::B2DPoint(),
+                                               ::basegfx::B2DRectangle( 0.0, 0.0,
+                                                                        FPS_BOUNDS.Right(),
+                                                                        FPS_BOUNDS.Bottom() ) );
+            }
+
+            // background has not changed, so we're free to optimize
+            // repaint to areas where a sprite has changed
+
+            // process each independent area of overlapping sprites
+            // separately.
+            mpRedrawManager->forEachSpriteArea( *this );
+        }
+        else
+        {
+            // background has changed, so we currently have no choice
+            // but repaint everything (or caller requested that)
+
+            maVDev->SetOutputSizePixel( aOutDevSize );
+            maVDev->EnableMapMode( false );
+            maVDev->DrawOutDev( aEmptyPoint, aOutDevSize,
+                                aEmptyPoint, aOutDevSize,
+                                rBackOutDev );
+
+            // repaint all active sprites on top of background into
+            // VDev.
+            OutputDevice& rTmpOutDev( *maVDev );
+            mpRedrawManager->forEachSprite(
+                    [&rTmpOutDev]( const ::canvas::Sprite::Reference& rSprite )
+                    { spriteRedraw( rTmpOutDev, rSprite ); }
+                    );
+
+            // flush to screen
+            rOutDev.EnableMapMode( false );
+            rOutDev.SetAntialiasing( AntialiasingFlags::Enable );
+            rOutDev.SetClipRegion();
+            rOutDev.DrawOutDev( aEmptyPoint, aOutDevSize,
+                                aEmptyPoint, aOutDevSize,
+                                *maVDev );
+        }
+
+        // change record vector must be cleared, for the next turn of
+        // rendering and sprite changing
+        mpRedrawManager->clearChangeRecords();
+
+        io_bSurfaceDirty = false;
+
+        if( mbShowFrameInfo )
+        {
+            renderFrameCounter( rOutDev );
+            renderSpriteCount( rOutDev );
+            renderMemUsage( rOutDev );
+        }
+
+#if OSL_DEBUG_LEVEL > 0
+        static ::canvas::tools::ElapsedTime aElapsedTime;
+
+        // log time immediately after surface flip
+        SAL_INFO("canvas.vcl", "SpriteCanvasHelper::updateScreen(): flip done at " <<
+                   aElapsedTime.getElapsedTime() );
+#endif
+
+        // sync output with screen, to ensure that we don't queue up
+        // render requests (calling code might rely on timing,
+        // i.e. assume that things are visible on screen after
+        // updateScreen() returns).
+        if( pTargetWindow )
+        {
+            // commit to screen
+            pTargetWindow->GetOutDev()->Flush();
+        }
+
+        return true;
+    }
+
+    void SpriteCanvasHelper::backgroundPaint( const ::basegfx::B2DRange& rUpdateRect )
+    {
+        ENSURE_OR_THROW( mpOwningSpriteCanvas &&
+                         mpOwningSpriteCanvas->getBackBuffer() &&
+                         mpOwningSpriteCanvas->getFrontBuffer(),
+                         "SpriteCanvasHelper::backgroundPaint(): NULL device pointer " );
+
+        OutputDevice&       rOutDev( mpOwningSpriteCanvas->getFrontBuffer()->getOutDev() );
+        BackBufferSharedPtr pBackBuffer( mpOwningSpriteCanvas->getBackBuffer() );
+        OutputDevice&       rBackOutDev( pBackBuffer->getOutDev() );
+
+        repaintBackground( rOutDev, rBackOutDev, rUpdateRect );
+    }
+
+    void SpriteCanvasHelper::scrollUpdate( const ::basegfx::B2DRange&                       rMoveStart,
+                                           const ::basegfx::B2DRange&                       rMoveEnd,
+                                           const ::canvas::SpriteRedrawManager::UpdateArea& rUpdateArea )
+    {
+        ENSURE_OR_THROW( mpOwningSpriteCanvas &&
+                         mpOwningSpriteCanvas->getBackBuffer() &&
+                         mpOwningSpriteCanvas->getFrontBuffer(),
+                         "SpriteCanvasHelper::scrollUpdate(): NULL device pointer " );
+
+        OutputDevice&       rOutDev( mpOwningSpriteCanvas->getFrontBuffer()->getOutDev() );
+        BackBufferSharedPtr pBackBuffer( mpOwningSpriteCanvas->getBackBuffer() );
+        OutputDevice&       rBackOutDev( pBackBuffer->getOutDev() );
+
+        const Size&                rTargetSizePixel( rOutDev.GetOutputSizePixel() );
+        const ::basegfx::B2IRange  aOutputBounds( 0,0,
+                                                  rTargetSizePixel.Width(),
+                                                  rTargetSizePixel.Height() );
+
+        // round rectangles to integer pixel. Note: have to be
+        // extremely careful here, to avoid off-by-one errors for
+        // the destination area: otherwise, the next scroll update
+        // would copy pixel that are not supposed to be part of
+        // the sprite.
+        ::basegfx::B2IRange aSourceRect(
+            ::canvas::tools::spritePixelAreaFromB2DRange( rMoveStart ) );
+        const ::basegfx::B2IRange& rDestRect(
+            ::canvas::tools::spritePixelAreaFromB2DRange( rMoveEnd ) );
+        ::basegfx::B2IPoint aDestPos( rDestRect.getMinimum() );
+
+        std::vector< ::basegfx::B2IRange > aUnscrollableAreas;
+
+        // Since strictly speaking, this scroll algorithm is plain
+        // buggy, the scrolled area might actually lie _below_ another
+        // window - we've made this feature configurable via
+        // mbIsUnsafeScrolling.
+
+        // clip to output bounds (cannot properly scroll stuff
+        // _outside_ our screen area)
+        if( !mbIsUnsafeScrolling ||
+            !::canvas::tools::clipScrollArea( aSourceRect,
+                                              aDestPos,
+                                              aUnscrollableAreas,
+                                              aOutputBounds ) )
+        {
+            // fully clipped scroll area: cannot simply scroll
+            // then. Perform normal opaque update (can use that, since
+            // one of the preconditions for scrollable update is
+            // opaque sprite content)
+
+            // repaint all affected sprites directly to output device
+            for( const auto& rComponent : rUpdateArea.maComponentList )
+            {
+                const ::canvas::Sprite::Reference& rSprite( rComponent.second.getSprite() );
+
+                if( rSprite.is() )
+                    ::boost::polymorphic_downcast< Sprite* >(
+                        rSprite.get() )->redraw( rOutDev,
+                                                 false );
+            }
+        }
+        else
+        {
+            // scroll rOutDev content
+            rOutDev.CopyArea( vcl::unotools::pointFromB2IPoint( aDestPos ),
+                              vcl::unotools::pointFromB2IPoint( aSourceRect.getMinimum() ),
+                              // TODO(Q2): use numeric_cast to check range
+                              ::Size( static_cast<sal_Int32>(aSourceRect.getRange().getX()),
+                                      static_cast<sal_Int32>(aSourceRect.getRange().getY()) ) );
+
+            const ::canvas::SpriteRedrawManager::SpriteConnectedRanges::ComponentListType::const_iterator
+                aFirst( rUpdateArea.maComponentList.begin() );
+
+            ENSURE_OR_THROW( aFirst->second.getSprite().is(),
+                              "VCLCanvas::scrollUpdate(): no sprite" );
+
+            // repaint uncovered areas from sprite. Need to actually
+            // clip here, since we're only repainting _parts_ of the
+            // sprite
+            rOutDev.Push( vcl::PushFlags::CLIPREGION );
+
+            for( const auto& rArea : aUnscrollableAreas )
+                opaqueUpdateSpriteArea( aFirst->second.getSprite(),
+                                        rOutDev, rArea );
+
+            rOutDev.Pop();
+        }
+
+        // repaint uncovered areas from backbuffer - take the
+        // _rounded_ rectangles from above, to have the update
+        // consistent with the scroll above.
+        std::vector< ::basegfx::B2DRange > aUncoveredAreas;
+        ::basegfx::computeSetDifference( aUncoveredAreas,
+                                         rUpdateArea.maTotalBounds,
+                                         ::basegfx::B2DRange( rDestRect ) );
+
+        for( const auto& rArea : aUncoveredAreas )
+            repaintBackground( rOutDev, rBackOutDev, rArea );
+    }
+
+    void SpriteCanvasHelper::opaqueUpdate( SAL_UNUSED_PARAMETER const ::basegfx::B2DRange&,
+                                           const std::vector< ::canvas::Sprite::Reference >& rSortedUpdateSprites )
+    {
+        ENSURE_OR_THROW( mpOwningSpriteCanvas &&
+                         mpOwningSpriteCanvas->getBackBuffer() &&
+                         mpOwningSpriteCanvas->getFrontBuffer(),
+                         "SpriteCanvasHelper::opaqueUpdate(): NULL device pointer " );
+
+        OutputDevice& rOutDev( mpOwningSpriteCanvas->getFrontBuffer()->getOutDev() );
+
+        // no need to clip output to actual update region - there will
+        // always be ALL sprites contained in the rectangular update
+        // area contained in rTotalArea (that's the way
+        // B2DConnectedRanges work). If rTotalArea appears to be
+        // smaller than the sprite - then this sprite carries a clip,
+        // and the update will be constrained to that rect.
+
+        // repaint all affected sprites directly to output device
+        for( const auto& rSprite : rSortedUpdateSprites )
+        {
+            if( rSprite.is() )
+                ::boost::polymorphic_downcast< Sprite* >(
+                    rSprite.get() )->redraw( rOutDev,
+                                             false );
+        }
+    }
+
+    void SpriteCanvasHelper::genericUpdate( const ::basegfx::B2DRange&                          rRequestedArea,
+                                            const std::vector< ::canvas::Sprite::Reference >& rSortedUpdateSprites )
+    {
+        ENSURE_OR_THROW( mpOwningSpriteCanvas &&
+                         mpOwningSpriteCanvas->getBackBuffer() &&
+                         mpOwningSpriteCanvas->getFrontBuffer(),
+                         "SpriteCanvasHelper::genericUpdate(): NULL device pointer " );
+
+        OutputDevice&       rOutDev( mpOwningSpriteCanvas->getFrontBuffer()->getOutDev() );
+        BackBufferSharedPtr pBackBuffer( mpOwningSpriteCanvas->getBackBuffer() );
+        OutputDevice&       rBackOutDev( pBackBuffer->getOutDev() );
+
+        // limit size of update VDev to target outdev's size
+        const Size& rTargetSizePixel( rOutDev.GetOutputSizePixel() );
+
+        // round output position towards zero. Don't want to truncate
+        // a fraction of a sprite pixel...  Clip position at origin,
+        // otherwise, truncation of size below might leave visible
+        // areas uncovered by VDev.
+        const ::Point aOutputPosition(
+            std::max( sal_Int32( 0 ),
+                        static_cast< sal_Int32 >(rRequestedArea.getMinX()) ),
+            std::max( sal_Int32( 0 ),
+                        static_cast< sal_Int32 >(rRequestedArea.getMinY()) ) );
+        // round output size towards +infty. Don't want to truncate a
+        // fraction of a sprite pixel... Limit coverage of VDev to
+        // output device's area (i.e. not only to total size, but to
+        // cover _only_ the visible parts).
+        const ::Size aOutputSize(
+            std::max( sal_Int32( 0 ),
+                        std::min( static_cast< sal_Int32 >(rTargetSizePixel.Width() - aOutputPosition.X()),
+                                    ::canvas::tools::roundUp( rRequestedArea.getMaxX() - aOutputPosition.X() ))),
+            std::max( sal_Int32( 0 ),
+                        std::min( static_cast< sal_Int32 >(rTargetSizePixel.Height() - aOutputPosition.Y()),
+                                    ::canvas::tools::roundUp( rRequestedArea.getMaxY() - aOutputPosition.Y() ))));
+
+        // early exit for empty output area.
+        if( aOutputSize.Width() == 0 &&
+            aOutputSize.Height() == 0 )
+        {
+            return;
+        }
+
+        const Point aEmptyPoint(0,0);
+        const Size  aCurrOutputSize( maVDev->GetOutputSizePixel() );
+
+        // adapt maVDev's size to the area that actually needs the
+        // repaint.
+        if( aCurrOutputSize.Width() < aOutputSize.Width() ||
+            aCurrOutputSize.Height() < aOutputSize.Height() )
+        {
+            // TODO(P1): Come up with a clever tactic to reduce maVDev
+            // from time to time. Reduction with threshold (say, if
+            // maVDev is more than twice too large) is not wise, as
+            // this might then toggle within the same updateScreen(),
+            // but for different disjunct sprite areas.
+            maVDev->SetOutputSizePixel( aOutputSize );
+        }
+
+        // paint background
+        maVDev->EnableMapMode( false );
+        maVDev->SetAntialiasing( AntialiasingFlags::Enable );
+        maVDev->SetClipRegion();
+        maVDev->DrawOutDev( aEmptyPoint, aOutputSize,
+                            aOutputPosition, aOutputSize,
+                            rBackOutDev );
+
+        // repaint all affected sprites on top of background into
+        // VDev.
+        for( const auto& rSprite : rSortedUpdateSprites )
+        {
+            if( rSprite.is() )
+            {
+                Sprite* pSprite = ::boost::polymorphic_downcast< Sprite* >( rSprite.get() );
+
+                // calc relative sprite position in rUpdateArea (which
+                // need not be the whole screen!)
+                const ::basegfx::B2DPoint& rSpriteScreenPos( pSprite->getPosPixel() );
+                const ::basegfx::B2DPoint& rSpriteRenderPos(
+                        rSpriteScreenPos - vcl::unotools::b2DPointFromPoint(aOutputPosition)
+                        );
+
+                pSprite->redraw( *maVDev, rSpriteRenderPos, true );
+            }
+        }
+
+        // flush to screen
+        rOutDev.EnableMapMode( false );
+        rOutDev.SetAntialiasing( AntialiasingFlags::Enable );
+        rOutDev.DrawOutDev( aOutputPosition, aOutputSize,
+                            aEmptyPoint, aOutputSize,
+                            *maVDev );
+    }
+
+    void SpriteCanvasHelper::renderFrameCounter( OutputDevice& rOutDev )
+    {
+        const double denominator( maLastUpdate.getElapsedTime() );
+        maLastUpdate.reset();
+
+        OUString text( ::rtl::math::doubleToUString( denominator == 0.0 ? 100.0 : 1.0/denominator,
+                                                            rtl_math_StringFormat_F,
+                                                            2,'.',nullptr,' ') );
+
+        // pad with leading space
+        while( text.getLength() < 6 )
+            text = " " + text;
+
+        text += " fps";
+
+        renderInfoText( rOutDev,
+                        text,
+                        Point(0, 0) );
+    }
+
+    namespace
+    {
+        template< typename T > struct Adder
+        {
+            typedef void result_type;
+
+            Adder( T& rAdderTarget,
+                   T  nIncrement ) :
+                mpTarget( &rAdderTarget ),
+                mnIncrement( nIncrement )
+            {
+            }
+
+            void operator()( const ::canvas::Sprite::Reference& ) { *mpTarget += mnIncrement; }
+            void operator()( T nIncrement ) { *mpTarget += nIncrement; }
+
+            T* mpTarget;
+            T  mnIncrement;
+        };
+
+        template< typename T> Adder<T> makeAdder( T& rAdderTarget,
+                                                  T  nIncrement )
+        {
+            return Adder<T>(rAdderTarget, nIncrement);
+        }
+    }
+
+    void SpriteCanvasHelper::renderSpriteCount( OutputDevice& rOutDev )
+    {
+        if( !mpRedrawManager )
+            return;
+
+        sal_Int32 nCount(0);
+
+        mpRedrawManager->forEachSprite( makeAdder(nCount,sal_Int32(1)) );
+        OUString text( OUString::number(nCount) );
+
+        // pad with leading space
+        while( text.getLength() < 3 )
+            text = " " + text;
+
+        text = "Sprites: " + text;
+
+        renderInfoText( rOutDev,
+                        text,
+                        Point(0, 30) );
+    }
+
+    void SpriteCanvasHelper::renderMemUsage( OutputDevice& rOutDev )
+    {
+        BackBufferSharedPtr pBackBuffer( mpOwningSpriteCanvas->getBackBuffer() );
+
+        if( !(mpRedrawManager &&
+            pBackBuffer) )
+            return;
+
+        double nPixel(0.0);
+
+        // accumulate pixel count for each sprite into fCount
+        mpRedrawManager->forEachSprite(
+                [&nPixel]( const ::canvas::Sprite::Reference& rSprite )
+                { makeAdder( nPixel, 1.0 )( calcNumPixel(rSprite) ); }
+                );
+
+        static const int NUM_VIRDEV(2);
+        static const int BYTES_PER_PIXEL(3);
+
+        const Size& rVDevSize( maVDev->GetOutputSizePixel() );
+        const Size& rBackBufferSize( pBackBuffer->getOutDev().GetOutputSizePixel() );
+
+        const double nMemUsage( nPixel * NUM_VIRDEV * BYTES_PER_PIXEL +
+                                rVDevSize.Width()*rVDevSize.Height() * BYTES_PER_PIXEL +
+                                rBackBufferSize.Width()*rBackBufferSize.Height() * BYTES_PER_PIXEL );
+
+        OUString text( ::rtl::math::doubleToUString( nMemUsage / 1048576.0,
+                                                            rtl_math_StringFormat_F,
+                                                            2,'.',nullptr,' ') );
+
+        // pad with leading space
+        while( text.getLength() < 4 )
+            text = " " + text;
+
+        text = "Mem: " + text + "MB";
+
+        renderInfoText( rOutDev,
+                        text,
+                        Point(0, 60) );
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */