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, 856 insertions, 0 deletions

diff --git a/slideshow/source/engine/shapes/viewshape.cxx b/slideshow/source/engine/shapes/viewshape.cxx
new file mode 100644
index 000000000..f2d909524
--- /dev/null
+++ b/slideshow/source/engine/shapes/viewshape.cxx
@@ -0,0 +1,856 @@
+/* -*- 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 <tools/diagnose_ex.h>
+
+#include <algorithm>
+
+#include <rtl/math.hxx>
+#include <sal/log.hxx>
+
+#include <com/sun/star/rendering/PanoseLetterForm.hpp>
+#include <com/sun/star/awt/FontSlant.hpp>
+
+#include <basegfx/numeric/ftools.hxx>
+#include <basegfx/matrix/b2dhommatrix.hxx>
+#include <basegfx/matrix/b2dhommatrixtools.hxx>
+
+#include <canvas/canvastools.hxx>
+#include <cppcanvas/vclfactory.hxx>
+#include <cppcanvas/basegfxfactory.hxx>
+
+#include "viewshape.hxx"
+#include <tools.hxx>
+
+using namespace ::com::sun::star;
+
+namespace slideshow::internal
+{
+
+        // TODO(F2): Provide sensible setup for mtf-related attributes (fill mode,
+        // char rotation etc.). Do that via mtf argument at this object
+
+        bool ViewShape::prefetch( RendererCacheEntry&                   io_rCacheEntry,
+                                  const ::cppcanvas::CanvasSharedPtr&   rDestinationCanvas,
+                                  const GDIMetaFileSharedPtr&           rMtf,
+                                  const ShapeAttributeLayerSharedPtr&   rAttr )
+        {
+            ENSURE_OR_RETURN_FALSE( rMtf,
+                               "ViewShape::prefetch(): no valid metafile!" );
+
+            if( rMtf != io_rCacheEntry.mpMtf ||
+                rDestinationCanvas != io_rCacheEntry.getDestinationCanvas() )
+            {
+                // buffered renderer invalid, re-create
+                ::cppcanvas::Renderer::Parameters aParms;
+
+                // rendering attribute override parameter struct.  For
+                // every valid attribute, the corresponding struct
+                // member is filled, which in the metafile renderer
+                // forces rendering with the given attribute.
+                if( rAttr )
+                {
+                    if( rAttr->isFillColorValid() )
+                    {
+                        // convert RGBColor to RGBA32 integer. Note
+                        // that getIntegerColor() also truncates
+                        // out-of-range values appropriately
+                        aParms.maFillColor =
+                            rAttr->getFillColor().getIntegerColor();
+                    }
+                    if( rAttr->isLineColorValid() )
+                    {
+                        // convert RGBColor to RGBA32 integer. Note
+                        // that getIntegerColor() also truncates
+                        // out-of-range values appropriately
+                        aParms.maLineColor =
+                            rAttr->getLineColor().getIntegerColor();
+                    }
+                    if( rAttr->isCharColorValid() )
+                    {
+                        // convert RGBColor to RGBA32 integer. Note
+                        // that getIntegerColor() also truncates
+                        // out-of-range values appropriately
+                        aParms.maTextColor =
+                            rAttr->getCharColor().getIntegerColor();
+                    }
+                    if( rAttr->isDimColorValid() )
+                    {
+                        // convert RGBColor to RGBA32 integer. Note
+                        // that getIntegerColor() also truncates
+                        // out-of-range values appropriately
+
+                        // dim color overrides all other colors
+                        aParms.maFillColor =
+                        aParms.maLineColor =
+                        aParms.maTextColor =
+                            rAttr->getDimColor().getIntegerColor();
+                    }
+                    if( rAttr->isFontFamilyValid() )
+                    {
+                        aParms.maFontName =
+                            rAttr->getFontFamily();
+                    }
+                    if( rAttr->isCharScaleValid() )
+                    {
+                        ::basegfx::B2DHomMatrix aMatrix;
+
+                        // enlarge text by given scale factor. Do that
+                        // with the middle of the shape as the center
+                        // of scaling.
+                        aMatrix.translate( -0.5, -0.5 );
+                        aMatrix.scale( rAttr->getCharScale(),
+                                       rAttr->getCharScale() );
+                        aMatrix.translate( 0.5, 0.5 );
+
+                        aParms.maTextTransformation = aMatrix;
+                    }
+                    if( rAttr->isCharWeightValid() )
+                    {
+                        aParms.maFontWeight =
+                            static_cast< sal_Int8 >(
+                                ::basegfx::fround(
+                                    ::std::max( 0.0,
+                                                ::std::min( 11.0,
+                                                            rAttr->getCharWeight() / 20.0 ) ) ) );
+                    }
+                    if( rAttr->isCharPostureValid() )
+                    {
+                        aParms.maFontLetterForm =
+                            rAttr->getCharPosture() == sal_Int16(awt::FontSlant_NONE) ?
+                            rendering::PanoseLetterForm::ANYTHING :
+                            rendering::PanoseLetterForm::OBLIQUE_CONTACT;
+                    }
+                    if( rAttr->isUnderlineModeValid() )
+                    {
+                        aParms.maFontUnderline =
+                            rAttr->getUnderlineMode();
+                    }
+                }
+
+                io_rCacheEntry.mpRenderer = ::cppcanvas::VCLFactory::createRenderer( rDestinationCanvas,
+                                                                                     *rMtf,
+                                                                                     aParms );
+
+                io_rCacheEntry.mpMtf               = rMtf;
+                io_rCacheEntry.mpDestinationCanvas = rDestinationCanvas;
+
+                // also invalidate alpha compositing bitmap (created
+                // new renderer, which possibly generates different
+                // output). Do NOT invalidate, if we're incidentally
+                // rendering INTO it.
+                if( rDestinationCanvas != io_rCacheEntry.mpLastBitmapCanvas )
+                {
+                    io_rCacheEntry.mpLastBitmapCanvas.reset();
+                    io_rCacheEntry.mpLastBitmap.reset();
+                }
+            }
+
+            return static_cast< bool >(io_rCacheEntry.mpRenderer);
+        }
+
+        bool ViewShape::draw( const ::cppcanvas::CanvasSharedPtr&   rDestinationCanvas,
+                              const GDIMetaFileSharedPtr&           rMtf,
+                              const ShapeAttributeLayerSharedPtr&   rAttr,
+                              const ::basegfx::B2DHomMatrix&        rTransform,
+                              const ::basegfx::B2DPolyPolygon*      pClip,
+                              const VectorOfDocTreeNodes&           rSubsets ) const
+        {
+            ::cppcanvas::RendererSharedPtr pRenderer(
+                getRenderer( rDestinationCanvas, rMtf, rAttr ) );
+
+            ENSURE_OR_RETURN_FALSE( pRenderer, "ViewShape::draw(): Invalid renderer" );
+
+            pRenderer->setTransformation( rTransform );
+#if OSL_DEBUG_LEVEL >= 2
+            rendering::RenderState aRenderState;
+            ::canvas::tools::initRenderState(aRenderState);
+            ::canvas::tools::setRenderStateTransform(aRenderState,
+                                                     rTransform);
+            aRenderState.DeviceColor.realloc(4);
+            aRenderState.DeviceColor[0] = 1.0;
+            aRenderState.DeviceColor[1] = 0.0;
+            aRenderState.DeviceColor[2] = 0.0;
+            aRenderState.DeviceColor[3] = 1.0;
+
+            try
+            {
+                rDestinationCanvas->getUNOCanvas()->drawLine( geometry::RealPoint2D(0.0,0.0),
+                                                              geometry::RealPoint2D(1.0,1.0),
+                                                              rDestinationCanvas->getViewState(),
+                                                              aRenderState );
+                rDestinationCanvas->getUNOCanvas()->drawLine( geometry::RealPoint2D(1.0,0.0),
+                                                              geometry::RealPoint2D(0.0,1.0),
+                                                              rDestinationCanvas->getViewState(),
+                                                              aRenderState );
+            }
+            catch( uno::Exception& )
+            {
+                DBG_UNHANDLED_EXCEPTION("slideshow");
+            }
+#endif
+            if( pClip )
+                pRenderer->setClip( *pClip );
+            else
+                pRenderer->setClip();
+
+            if( rSubsets.empty() )
+            {
+                return pRenderer->draw();
+            }
+            else
+            {
+                // render subsets of whole metafile
+
+
+                bool bRet(true);
+                for( const auto& rSubset : rSubsets )
+                {
+                    if( !pRenderer->drawSubset( rSubset.getStartIndex(),
+                                                rSubset.getEndIndex() ) )
+                        bRet = false;
+                }
+
+                return bRet;
+            }
+        }
+
+        namespace
+        {
+            /// Convert untransformed shape update area to device pixel.
+            ::basegfx::B2DRectangle shapeArea2AreaPixel( const ::basegfx::B2DHomMatrix& rCanvasTransformation,
+                                                         const ::basegfx::B2DRectangle& rUntransformedArea      )
+            {
+                // convert area to pixel, and add anti-aliasing border
+
+                // TODO(P1): Should the view transform some
+                // day contain rotation/shear, transforming
+                // the original bounds with the total
+                // transformation might result in smaller
+                // overall bounds.
+
+                ::basegfx::B2DRectangle aBoundsPixel;
+                ::canvas::tools::calcTransformedRectBounds( aBoundsPixel,
+                                                            rUntransformedArea,
+                                                            rCanvasTransformation );
+
+                // add antialiasing border around the shape (AA
+                // touches pixel _outside_ the nominal bound rect)
+                aBoundsPixel.grow( ::cppcanvas::Canvas::ANTIALIASING_EXTRA_SIZE );
+
+                return aBoundsPixel;
+            }
+
+            /// Convert shape unit rect to device pixel.
+            ::basegfx::B2DRectangle calcUpdateAreaPixel( const ::basegfx::B2DRectangle&         rUnitBounds,
+                                                         const ::basegfx::B2DHomMatrix&         rShapeTransformation,
+                                                         const ::basegfx::B2DHomMatrix&         rCanvasTransformation,
+                                                         const ShapeAttributeLayerSharedPtr&    pAttr                   )
+            {
+                // calc update area for whole shape (including
+                // character scaling)
+                return shapeArea2AreaPixel( rCanvasTransformation,
+                                            getShapeUpdateArea( rUnitBounds,
+                                                                rShapeTransformation,
+                                                                pAttr ) );
+            }
+        }
+
+        bool ViewShape::renderSprite( const ViewLayerSharedPtr&             rViewLayer,
+                                      const GDIMetaFileSharedPtr&           rMtf,
+                                      const ::basegfx::B2DRectangle&        rOrigBounds,
+                                      const ::basegfx::B2DRectangle&        rBounds,
+                                      const ::basegfx::B2DRectangle&        rUnitBounds,
+                                      UpdateFlags                           nUpdateFlags,
+                                      const ShapeAttributeLayerSharedPtr&   pAttr,
+                                      const VectorOfDocTreeNodes&           rSubsets,
+                                      double                                nPrio,
+                                      bool                                  bIsVisible ) const
+        {
+            // TODO(P1): For multiple views, it might pay off to reorg Shape and ViewShape,
+            // in that all the common setup steps here are refactored to Shape (would then
+            // have to be performed only _once_ per Shape paint).
+
+            if( !bIsVisible ||
+                rUnitBounds.isEmpty() ||
+                rOrigBounds.isEmpty() ||
+                rBounds.isEmpty() )
+            {
+                // shape is invisible or has zero size, no need to
+                // update anything.
+                if( mpSprite )
+                    mpSprite->hide();
+
+                return true;
+            }
+
+
+            // calc sprite position, size and content transformation
+            // =====================================================
+
+            // the shape transformation for a sprite is always a
+            // simple scale-up to the nominal shape size. Everything
+            // else is handled via the sprite transformation
+            ::basegfx::B2DHomMatrix aNonTranslationalShapeTransformation;
+            aNonTranslationalShapeTransformation.scale( rOrigBounds.getWidth(),
+                                                        rOrigBounds.getHeight() );
+            ::basegfx::B2DHomMatrix aShapeTransformation( aNonTranslationalShapeTransformation );
+            aShapeTransformation.translate( rOrigBounds.getMinX(),
+                                            rOrigBounds.getMinY() );
+
+            const ::basegfx::B2DHomMatrix& rCanvasTransform(
+                rViewLayer->getSpriteTransformation() );
+
+            // area actually needed for the sprite
+            const ::basegfx::B2DRectangle& rSpriteBoundsPixel(
+                calcUpdateAreaPixel( rUnitBounds,
+                                     aShapeTransformation,
+                                     rCanvasTransform,
+                                     pAttr ) );
+
+            // actual area for the shape (without subsetting, but
+            // including char scaling)
+            const ::basegfx::B2DRectangle& rShapeBoundsPixel(
+                calcUpdateAreaPixel( ::basegfx::B2DRectangle(0.0,0.0,1.0,1.0),
+                                     aShapeTransformation,
+                                     rCanvasTransform,
+                                     pAttr ) );
+
+            // nominal area for the shape (without subsetting, without
+            // char scaling). NOTE: to cancel the shape translation,
+            // contained in rSpriteBoundsPixel, this is _without_ any
+            // translational component.
+            ::basegfx::B2DRectangle        aLogShapeBounds;
+            const ::basegfx::B2DRectangle& rNominalShapeBoundsPixel(
+                shapeArea2AreaPixel( rCanvasTransform,
+                                     ::canvas::tools::calcTransformedRectBounds(
+                                         aLogShapeBounds,
+                                         ::basegfx::B2DRectangle(0.0,0.0,1.0,1.0),
+                                         aNonTranslationalShapeTransformation ) ) );
+
+            // create (or resize) sprite with sprite's pixel size, if
+            // not done already
+            const ::basegfx::B2DSize& rSpriteSizePixel(rSpriteBoundsPixel.getRange());
+            if( !mpSprite )
+            {
+                mpSprite = std::make_shared<AnimatedSprite>( mpViewLayer,
+                                        rSpriteSizePixel,
+                                        nPrio );
+            }
+            else
+            {
+                // TODO(F2): when the sprite _actually_ gets resized,
+                // content needs a repaint!
+                mpSprite->resize( rSpriteSizePixel );
+            }
+
+            ENSURE_OR_RETURN_FALSE( mpSprite, "ViewShape::renderSprite(): No sprite" );
+
+            SAL_INFO("slideshow", "ViewShape::renderSprite(): Rendering sprite " <<
+                           mpSprite.get() );
+
+
+            // always show the sprite (might have been hidden before)
+            mpSprite->show();
+
+            // determine center of sprite output position in pixel
+            // (assumption here: all shape transformations have the
+            // shape center as the pivot point). From that, subtract
+            // distance of rSpriteBoundsPixel's left, top edge from
+            // rShapeBoundsPixel's center. This moves the sprite at
+            // the appropriate output position within the virtual
+            // rShapeBoundsPixel area.
+            ::basegfx::B2DPoint aSpritePosPixel( rBounds.getCenter() );
+            aSpritePosPixel *= rCanvasTransform;
+            aSpritePosPixel -= rShapeBoundsPixel.getCenter() - rSpriteBoundsPixel.getMinimum();
+
+            // the difference between rShapeBoundsPixel and
+            // rSpriteBoundsPixel upper, left corner is: the offset we
+            // have to move sprite output to the right, top (to make
+            // the desired subset content visible at all)
+            const ::basegfx::B2DSize& rSpriteCorrectionOffset(
+                rSpriteBoundsPixel.getMinimum() - rNominalShapeBoundsPixel.getMinimum() );
+
+            // offset added top, left for anti-aliasing (otherwise,
+            // shapes fully filling the sprite will have anti-aliased
+            // pixel cut off)
+            const ::basegfx::B2DSize aAAOffset(
+                ::cppcanvas::Canvas::ANTIALIASING_EXTRA_SIZE,
+                ::cppcanvas::Canvas::ANTIALIASING_EXTRA_SIZE );
+
+            // set pixel output offset to sprite: we always leave
+            // ANTIALIASING_EXTRA_SIZE room atop and to the left, and,
+            // what's more, for subsetted shapes, we _have_ to cancel
+            // the effect of the shape renderer outputting the subset
+            // at its absolute position inside the shape, instead of
+            // at the origin.
+            // NOTE: As for now, sprites are always positioned on
+            // integer pixel positions on screen, have to round to
+            // nearest integer here, too
+            mpSprite->setPixelOffset(
+                aAAOffset - ::basegfx::B2DSize(
+                    ::basegfx::fround( rSpriteCorrectionOffset.getX() ),
+                    ::basegfx::fround( rSpriteCorrectionOffset.getY() ) ) );
+
+            // always set sprite position and transformation, since
+            // they do not relate directly to the update flags
+            // (e.g. sprite position changes when sprite size changes)
+            mpSprite->movePixel( aSpritePosPixel );
+            mpSprite->transform( getSpriteTransformation( rSpriteSizePixel,
+                                                          rOrigBounds.getRange(),
+                                                          pAttr ) );
+
+
+            // process flags
+            // =============
+
+            bool bRedrawRequired( mbForceUpdate || (nUpdateFlags & UpdateFlags::Force) );
+
+            if( mbForceUpdate || (nUpdateFlags & UpdateFlags::Alpha) )
+            {
+                mpSprite->setAlpha( (pAttr && pAttr->isAlphaValid()) ?
+                                    std::clamp(pAttr->getAlpha(),
+                                                     0.0,
+                                                     1.0) :
+                                    1.0 );
+            }
+            if( mbForceUpdate || (nUpdateFlags & UpdateFlags::Clip) )
+            {
+                if( pAttr && pAttr->isClipValid() )
+                {
+                    ::basegfx::B2DPolyPolygon aClipPoly( pAttr->getClip() );
+
+                    // extract linear part of canvas view transformation
+                    // (linear means: without translational components)
+                    ::basegfx::B2DHomMatrix aViewTransform(
+                        mpViewLayer->getTransformation() );
+                    aViewTransform.set( 0, 2, 0.0 );
+                    aViewTransform.set( 1, 2, 0.0 );
+
+                    // make the clip 2*ANTIALIASING_EXTRA_SIZE larger
+                    // such that it's again centered over the sprite.
+                    aViewTransform.scale(rSpriteSizePixel.getX()/
+                                         (rSpriteSizePixel.getX()-2*::cppcanvas::Canvas::ANTIALIASING_EXTRA_SIZE),
+                                         rSpriteSizePixel.getY()/
+                                         (rSpriteSizePixel.getY()-2*::cppcanvas::Canvas::ANTIALIASING_EXTRA_SIZE));
+
+                    // transform clip polygon from view to device
+                    // coordinate space
+                    aClipPoly.transform( aViewTransform );
+
+                    mpSprite->clip( aClipPoly );
+                }
+                else
+                    mpSprite->clip();
+            }
+            if( mbForceUpdate || (nUpdateFlags & UpdateFlags::Content) )
+            {
+                bRedrawRequired = true;
+
+                // TODO(P1): maybe provide some appearance change methods at
+                // the Renderer interface
+
+                // force the renderer to be regenerated below, for the
+                // different attributes to take effect
+                invalidateRenderer();
+            }
+
+            mbForceUpdate = false;
+
+            if( !bRedrawRequired )
+                return true;
+
+
+            // sprite needs repaint - output to sprite canvas
+            // ==============================================
+
+            ::cppcanvas::CanvasSharedPtr pContentCanvas( mpSprite->getContentCanvas() );
+
+            return draw( pContentCanvas,
+                         rMtf,
+                         pAttr,
+                         aShapeTransformation,
+                         nullptr, // clipping is done via Sprite::clip()
+                         rSubsets );
+        }
+
+        bool ViewShape::render( const ::cppcanvas::CanvasSharedPtr& rDestinationCanvas,
+                                const GDIMetaFileSharedPtr&         rMtf,
+                                const ::basegfx::B2DRectangle&      rBounds,
+                                const ::basegfx::B2DRectangle&      rUpdateBounds,
+                                UpdateFlags                         nUpdateFlags,
+                                const ShapeAttributeLayerSharedPtr& pAttr,
+                                const VectorOfDocTreeNodes&         rSubsets,
+                                bool                                bIsVisible ) const
+        {
+            // TODO(P1): For multiple views, it might pay off to reorg Shape and ViewShape,
+            // in that all the common setup steps here are refactored to Shape (would then
+            // have to be performed only _once_ per Shape paint).
+
+            if( !bIsVisible )
+            {
+                SAL_INFO("slideshow", "ViewShape::render(): skipping shape " << this );
+
+                // shape is invisible, no need to update anything.
+                return true;
+            }
+
+            // since we have no sprite here, _any_ update request
+            // translates into a required redraw.
+            bool bRedrawRequired( mbForceUpdate || nUpdateFlags != UpdateFlags::NONE );
+
+            if( nUpdateFlags & UpdateFlags::Content )
+            {
+                // TODO(P1): maybe provide some appearance change methods at
+                // the Renderer interface
+
+                // force the renderer to be regenerated below, for the
+                // different attributes to take effect
+                invalidateRenderer();
+            }
+
+            mbForceUpdate = false;
+
+            if( !bRedrawRequired )
+                return true;
+
+            SAL_INFO( "slideshow", "ViewShape::render(): rendering shape " <<
+                      this <<
+                      " at position (" <<
+                      rBounds.getMinX() << "," <<
+                      rBounds.getMinY() << ")" );
+
+
+            // shape needs repaint - setup all that's needed
+
+
+            std::optional<basegfx::B2DPolyPolygon> aClip;
+
+            if( pAttr )
+            {
+                // setup clip poly
+                if( pAttr->isClipValid() )
+                    aClip = pAttr->getClip();
+
+                // emulate global shape alpha by first rendering into
+                // a temp bitmap, and then to screen (this would have
+                // been much easier if we'd be currently a sprite -
+                // see above)
+                if( pAttr->isAlphaValid() )
+                {
+                    const double nAlpha( pAttr->getAlpha() );
+
+                    if( !::basegfx::fTools::equalZero( nAlpha ) &&
+                        !::rtl::math::approxEqual(nAlpha, 1.0) )
+                    {
+                        // render with global alpha - have to prepare
+                        // a bitmap, and render that with modulated
+                        // alpha
+
+
+                        const ::basegfx::B2DHomMatrix aTransform(
+                            getShapeTransformation( rBounds,
+                                                    pAttr ) );
+
+                        // TODO(P1): Should the view transform some
+                        // day contain rotation/shear, transforming
+                        // the original bounds with the total
+                        // transformation might result in smaller
+                        // overall bounds.
+
+                        // determine output rect of _shape update
+                        // area_ in device pixel
+                        const ::basegfx::B2DHomMatrix aCanvasTransform(
+                            rDestinationCanvas->getTransformation() );
+                        ::basegfx::B2DRectangle aTmpRect;
+                        ::canvas::tools::calcTransformedRectBounds( aTmpRect,
+                                                                    rUpdateBounds,
+                                                                    aCanvasTransform );
+
+                        // pixel size of cache bitmap: round up to
+                        // nearest int
+                        const ::basegfx::B2ISize aBmpSize( static_cast<sal_Int32>( aTmpRect.getWidth() )+1,
+                                                           static_cast<sal_Int32>( aTmpRect.getHeight() )+1 );
+
+                        // try to fetch temporary surface for alpha
+                        // compositing (to achieve the global alpha
+                        // blend effect, have to first render shape as
+                        // a whole, then blit that surface with global
+                        // alpha to the destination)
+                        const RendererCacheVector::iterator aCompositingSurface(
+                            getCacheEntry( rDestinationCanvas ) );
+
+                        if( !aCompositingSurface->mpLastBitmapCanvas ||
+                            aCompositingSurface->mpLastBitmapCanvas->getSize() != aBmpSize )
+                        {
+                            // create a bitmap of appropriate size
+                            ::cppcanvas::BitmapSharedPtr pBitmap(
+                                ::cppcanvas::BaseGfxFactory::createAlphaBitmap(
+                                    rDestinationCanvas,
+                                    aBmpSize ) );
+
+                            ENSURE_OR_THROW(pBitmap,
+                                             "ViewShape::render(): Could not create compositing surface");
+
+                            aCompositingSurface->mpDestinationCanvas = rDestinationCanvas;
+                            aCompositingSurface->mpLastBitmap        = pBitmap;
+                            aCompositingSurface->mpLastBitmapCanvas  = pBitmap->getBitmapCanvas();
+                        }
+
+                        // buffer aCompositingSurface iterator content
+                        // - said one might get invalidated during
+                        // draw() below.
+                        ::cppcanvas::BitmapCanvasSharedPtr pBitmapCanvas(
+                            aCompositingSurface->mpLastBitmapCanvas );
+
+                        ::cppcanvas::BitmapSharedPtr pBitmap(
+                            aCompositingSurface->mpLastBitmap);
+
+                        // setup bitmap canvas transformation -
+                        // which happens to be the destination
+                        // canvas transformation without any
+                        // translational components.
+
+                        // But then, the render transformation as
+                        // calculated by getShapeTransformation()
+                        // above outputs the shape at its real
+                        // destination position. Thus, we have to
+                        // offset the output back to the origin,
+                        // for which we simply plug in the
+                        // negative position of the left, top edge
+                        // of the shape's bound rect in device
+                        // pixel into aLinearTransform below.
+                        ::basegfx::B2DHomMatrix aAdjustedCanvasTransform( aCanvasTransform );
+                        aAdjustedCanvasTransform.translate( -aTmpRect.getMinX(),
+                                                            -aTmpRect.getMinY() );
+
+                        pBitmapCanvas->setTransformation( aAdjustedCanvasTransform );
+
+                        // TODO(P2): If no update flags, or only
+                        // alpha_update is set, we can save us the
+                        // rendering into the bitmap (uh, it's not
+                        // _that_ easy - for a forced redraw,
+                        // e.g. when ending an animation, we always
+                        // get UPDATE_FORCE here).
+
+                        // render into this bitmap
+                        if( !draw( pBitmapCanvas,
+                                   rMtf,
+                                   pAttr,
+                                   aTransform,
+                                   !aClip ? nullptr : &(*aClip),
+                                   rSubsets ) )
+                        {
+                            return false;
+                        }
+
+                        // render bitmap to screen, with given global
+                        // alpha. Since the bitmap already contains
+                        // pixel-equivalent output, we have to use the
+                        // inverse view transformation, adjusted with
+                        // the final shape output position (note:
+                        // cannot simply change the view
+                        // transformation here, as that would affect a
+                        // possibly set clip!)
+                        ::basegfx::B2DHomMatrix aBitmapTransform( aCanvasTransform );
+                        OSL_ENSURE( aBitmapTransform.isInvertible(),
+                                    "ViewShape::render(): View transformation is singular!" );
+
+                        aBitmapTransform.invert();
+
+                        const basegfx::B2DHomMatrix aTranslation(basegfx::utils::createTranslateB2DHomMatrix(
+                            aTmpRect.getMinX(), aTmpRect.getMinY()));
+
+                        aBitmapTransform = aBitmapTransform * aTranslation;
+                        pBitmap->setTransformation( aBitmapTransform );
+
+                        // finally, render bitmap alpha-modulated
+                        pBitmap->drawAlphaModulated( nAlpha );
+
+                        return true;
+                    }
+                }
+            }
+
+            // retrieve shape transformation, _with_ shape translation
+            // to actual page position.
+            const ::basegfx::B2DHomMatrix aTransform(
+                getShapeTransformation( rBounds,
+                                        pAttr ) );
+
+            return draw( rDestinationCanvas,
+                         rMtf,
+                         pAttr,
+                         aTransform,
+                         !aClip ? nullptr : &(*aClip),
+                         rSubsets );
+        }
+
+
+        ViewShape::ViewShape( const ViewLayerSharedPtr& rViewLayer ) :
+            mpViewLayer( rViewLayer ),
+            maRenderers(),
+            mpSprite(),
+            mbAnimationMode( false ),
+            mbForceUpdate( true )
+        {
+            ENSURE_OR_THROW( mpViewLayer, "ViewShape::ViewShape(): Invalid View" );
+        }
+
+        const ViewLayerSharedPtr& ViewShape::getViewLayer() const
+        {
+            return mpViewLayer;
+        }
+
+        ViewShape::RendererCacheVector::iterator ViewShape::getCacheEntry( const ::cppcanvas::CanvasSharedPtr&  rDestinationCanvas ) const
+        {
+            // lookup destination canvas - is there already a renderer
+            // created for that target?
+            RendererCacheVector::iterator       aIter;
+            const RendererCacheVector::iterator aEnd( maRenderers.end() );
+
+            // already there?
+            if( (aIter=::std::find_if( maRenderers.begin(),
+                                       aEnd,
+                                       [&rDestinationCanvas]( const RendererCacheEntry& rCacheEntry )
+                                       { return rDestinationCanvas == rCacheEntry.getDestinationCanvas(); } ) ) == aEnd )
+            {
+                if( maRenderers.size() >= MAX_RENDER_CACHE_ENTRIES )
+                {
+                    // cache size exceeded - prune entries. For now,
+                    // simply remove the first one, which of course
+                    // breaks for more complex access schemes. But in
+                    // general, this leads to most recently used
+                    // entries to reside at the end of the vector.
+                    maRenderers.erase( maRenderers.begin() );
+
+                    // ATTENTION: after this, both aIter and aEnd are
+                    // invalid!
+                }
+
+                // not yet in cache - add default-constructed cache
+                // entry, to have something to return
+                maRenderers.emplace_back( );
+                aIter = maRenderers.end()-1;
+            }
+
+            return aIter;
+        }
+
+        ::cppcanvas::RendererSharedPtr ViewShape::getRenderer( const ::cppcanvas::CanvasSharedPtr&  rDestinationCanvas,
+                                                               const GDIMetaFileSharedPtr&          rMtf,
+                                                               const ShapeAttributeLayerSharedPtr&  rAttr ) const
+        {
+            // lookup destination canvas - is there already a renderer
+            // created for that target?
+            const RendererCacheVector::iterator aIter(
+                getCacheEntry( rDestinationCanvas ) );
+
+            // now we have a valid entry, either way. call prefetch()
+            // on it, nevertheless - maybe the metafile changed, and
+            // the renderer still needs an update (prefetch() will
+            // detect that)
+            if( prefetch( *aIter,
+                          rDestinationCanvas,
+                          rMtf,
+                          rAttr ) )
+            {
+                return aIter->mpRenderer;
+            }
+            else
+            {
+                // prefetch failed - renderer is invalid
+                return ::cppcanvas::RendererSharedPtr();
+            }
+        }
+
+        void ViewShape::invalidateRenderer() const
+        {
+            // simply clear the cache. Subsequent getRenderer() calls
+            // will regenerate the Renderers.
+            maRenderers.clear();
+        }
+
+        ::basegfx::B2DSize ViewShape::getAntialiasingBorder() const
+        {
+            ENSURE_OR_THROW( mpViewLayer->getCanvas(),
+                              "ViewShape::getAntialiasingBorder(): Invalid ViewLayer canvas" );
+
+            const ::basegfx::B2DHomMatrix& rViewTransform(
+                mpViewLayer->getTransformation() );
+
+            // TODO(F1): As a quick shortcut (did not want to invert
+            // whole matrix here), taking only scale components of
+            // view transformation matrix. This will be wrong when
+            // e.g. shearing is involved.
+            const double nXBorder( ::cppcanvas::Canvas::ANTIALIASING_EXTRA_SIZE / rViewTransform.get(0,0) );
+            const double nYBorder( ::cppcanvas::Canvas::ANTIALIASING_EXTRA_SIZE / rViewTransform.get(1,1) );
+
+            return ::basegfx::B2DSize( nXBorder,
+                                       nYBorder );
+        }
+
+        void ViewShape::enterAnimationMode()
+        {
+            mbForceUpdate   = true;
+            mbAnimationMode = true;
+        }
+
+        void ViewShape::leaveAnimationMode()
+        {
+            mpSprite.reset();
+            mbAnimationMode = false;
+            mbForceUpdate   = true;
+        }
+
+        bool ViewShape::update( const GDIMetaFileSharedPtr& rMtf,
+                                const RenderArgs&           rArgs,
+                                UpdateFlags                 nUpdateFlags,
+                                bool                        bIsVisible ) const
+        {
+            ENSURE_OR_RETURN_FALSE( mpViewLayer->getCanvas(), "ViewShape::update(): Invalid layer canvas" );
+
+            // Shall we render to a sprite, or to a plain canvas?
+            if( mbAnimationMode )
+                return renderSprite( mpViewLayer,
+                                     rMtf,
+                                     rArgs.maOrigBounds,
+                                     rArgs.maBounds,
+                                     rArgs.maUnitBounds,
+                                     nUpdateFlags,
+                                     rArgs.mrAttr,
+                                     rArgs.mrSubsets,
+                                     rArgs.mnShapePriority,
+                                     bIsVisible );
+            else
+                return render( mpViewLayer->getCanvas(),
+                               rMtf,
+                               rArgs.maBounds,
+                               rArgs.maUpdateBounds,
+                               nUpdateFlags,
+                               rArgs.mrAttr,
+                               rArgs.mrSubsets,
+                               bIsVisible );
+        }
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */