spriteredrawmanager.cxx

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 * 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 <algorithm>
 
#include <basegfx/range/b2drectangle.hxx>
#include <basegfx/utils/canvastools.hxx>
#include <comphelper/diagnose_ex.hxx>
#include <sal/log.hxx>
 
#include <spriteredrawmanager.hxx>
#include <boost/range/adaptor/reversed.hpp>
#include <utility>
 
namespace canvas
{
    namespace
    {
        class SpriteTracer
        {
        public:
            explicit SpriteTracer( Sprite::Reference rAffectedSprite ) :
                mpAffectedSprite(std::move(rAffectedSprite)),
                mbIsMove( false ),
                mbIsGenericUpdate( false )
            {
            }
 
            void operator()( const SpriteRedrawManager::SpriteChangeRecord& rSpriteRecord )
            {
                // only deal with change events from the currently
                // affected sprite
                if( rSpriteRecord.mpAffectedSprite != mpAffectedSprite )
                    return;
 
                switch( rSpriteRecord.meChangeType )
                {
                    case SpriteRedrawManager::SpriteChangeRecord::ChangeType::move:
                        if( !mbIsMove )
                        {
                            // no move yet - this must be the first one
                            maMoveStartArea = ::basegfx::B2DRectangle(
                                rSpriteRecord.maOldPos,
                                rSpriteRecord.maOldPos + rSpriteRecord.maUpdateArea.getRange() );
                            mbIsMove        = true;
                        }
 
                        maMoveEndArea   = rSpriteRecord.maUpdateArea;
                        break;
 
                    case SpriteRedrawManager::SpriteChangeRecord::ChangeType::update:
                        // update end update area of the
                        // sprite. Thus, every update() action
                        // _after_ the last move will correctly
                        // update the final repaint area. And this
                        // does not interfere with subsequent
                        // moves, because moves always perform a
                        // hard set of maMoveEndArea to their
                        // stored value
                        maMoveEndArea.expand( rSpriteRecord.maUpdateArea );
                        mbIsGenericUpdate = true;
                        break;
 
                    default:
                        ENSURE_OR_THROW( false,
                                          "Unexpected case in SpriteUpdater::operator()" );
                        break;
                }
            }
 
            void commit( SpriteRedrawManager::SpriteConnectedRanges& rUpdateCollector ) const
            {
                if( mbIsMove )
                {
                    if( !maMoveStartArea.isEmpty() ||
                        !maMoveEndArea.isEmpty() )
                    {
                        // if mbIsGenericUpdate is false, this is a
                        // pure move (i.e. no other update
                        // operations). Pass that information on to
                        // the SpriteInfo
                        const bool bIsPureMove( !mbIsGenericUpdate );
 
                        // ignore the case that start and end update
                        // area overlap - the b2dconnectedranges
                        // handle that, anyway. doing it this way
                        // ensures that we have both old and new area
                        // stored
 
                        // round all given range up to enclosing
                        // integer rectangle - since the whole thing
                        // here is about
 
                        // first, draw the new sprite position
                        rUpdateCollector.addRange(
                            ::basegfx::unotools::b2DSurroundingIntegerRangeFromB2DRange( maMoveEndArea ),
                            SpriteRedrawManager::SpriteInfo(
                                mpAffectedSprite,
                                maMoveEndArea,
                                true,
                                bIsPureMove ) );
 
                        // then, clear the old place (looks smoother
                        // this way)
                        rUpdateCollector.addRange(
                            ::basegfx::unotools::b2DSurroundingIntegerRangeFromB2DRange( maMoveStartArea ),
                            SpriteRedrawManager::SpriteInfo(
                                Sprite::Reference(),
                                maMoveStartArea,
                                true,
                                bIsPureMove ) );
                    }
                }
                else if( mbIsGenericUpdate &&
                         !maMoveEndArea.isEmpty() )
                {
                    rUpdateCollector.addRange(
                        ::basegfx::unotools::b2DSurroundingIntegerRangeFromB2DRange( maMoveEndArea ),
                        SpriteRedrawManager::SpriteInfo(
                            mpAffectedSprite,
                            maMoveEndArea,
                            true ) );
                }
            }
 
        private:
            Sprite::Reference       mpAffectedSprite;
            ::basegfx::B2DRectangle maMoveStartArea;
            ::basegfx::B2DRectangle maMoveEndArea;
 
            bool                    mbIsMove;
 
            bool                    mbIsGenericUpdate;
        };
 
 
        class SpriteUpdater
        {
        public:
            SpriteUpdater( SpriteRedrawManager::SpriteConnectedRanges&          rUpdater,
                           const SpriteRedrawManager::VectorOfChangeRecords&    rChangeContainer ) :
                mrUpdater( rUpdater ),
                mrChangeContainer( rChangeContainer )
            {
            }
 
            void operator()( const Sprite::Reference& rSprite )
            {
                SpriteTracer aSpriteTracer( rSprite );
 
                for (auto const& aChange : mrChangeContainer)
                    aSpriteTracer( aChange );
 
                aSpriteTracer.commit( mrUpdater );
            }
 
        private:
            SpriteRedrawManager::SpriteConnectedRanges&         mrUpdater;
            const SpriteRedrawManager::VectorOfChangeRecords&   mrChangeContainer;
        };
    }
 
    void SpriteRedrawManager::setupUpdateAreas( SpriteConnectedRanges& rUpdateAreas ) const
    {
        // TODO(T3): This is NOT thread safe at all. This only works
        // under the assumption that NOBODY changes ANYTHING
        // concurrently, while this method is on the stack. We should
        // really rework the canvas::Sprite interface, in such a way
        // that it dumps ALL its state with a single, atomic
        // call. Then, we store that state locally. This prolly goes
        // in line with the problem of having sprite state available
        // for the frame before the last frame; plus, it avoids
        // frequent locks of the object mutexes
        SpriteWeakOrder aSpriteComparator;
 
        // put all sprites that have changed content into update areas
        for( const auto& pSprite : maSprites )
        {
            if( pSprite->isContentChanged() )
                const_cast< SpriteRedrawManager* >( this )->updateSprite( pSprite,
                                                                          pSprite->getPosPixel(),
                                                                          pSprite->getUpdateArea() );
        }
 
        // sort sprites after prio
        VectorOfSprites aSortedSpriteVector( maSprites.begin(), maSprites.end() );
        std::sort( aSortedSpriteVector.begin(),
                     aSortedSpriteVector.end(),
                     aSpriteComparator );
 
        // extract all referenced sprites from the maChangeRecords
        // (copy sprites, make the list unique, regarding the
        // sprite pointer). This assumes that, until this scope
        // ends, nobody changes the maChangeRecords vector!
        VectorOfSprites aUpdatableSprites;
        for( const auto& rChangeRecord : maChangeRecords )
        {
            const Sprite::Reference& rSprite( rChangeRecord.getSprite() );
            if( rSprite.is() )
                aUpdatableSprites.push_back( rSprite );
        }
 
        std::sort( aUpdatableSprites.begin(),
                     aUpdatableSprites.end(),
                     aSpriteComparator );
 
        VectorOfSprites::iterator aEnd=
            std::unique( aUpdatableSprites.begin(),
                           aUpdatableSprites.end() );
 
        // for each unique sprite, check the change event vector,
        // calculate the update operation from that, and add the
        // result to the aUpdateArea.
        std::for_each( aUpdatableSprites.begin(),
                         aEnd,
                         SpriteUpdater( rUpdateAreas,
                                        maChangeRecords) );
 
        // TODO(P2): Implement your own output iterator adapter, to
        // avoid that totally superfluous temp aUnchangedSprites
        // vector.
 
        // add all sprites to rUpdateAreas, that are _not_ already
        // contained in the uniquified vector of changed ones
        // (i.e. the difference between aSortedSpriteVector and
        // aUpdatableSprites).
        VectorOfSprites aUnchangedSprites;
        std::set_difference( aSortedSpriteVector.begin(),
                               aSortedSpriteVector.end(),
                               aUpdatableSprites.begin(),
                               aEnd,
                               std::back_insert_iterator< VectorOfSprites >(aUnchangedSprites),
                               aSpriteComparator );
 
        // add each remaining unchanged sprite to connected ranges,
        // marked as "don't need update"
        for( const auto& pUnchangedSprite : aUnchangedSprites )
        {
            const ::basegfx::B2DRange& rUpdateArea( pUnchangedSprite->getUpdateArea() );
            rUpdateAreas.addRange(
                ::basegfx::unotools::b2DSurroundingIntegerRangeFromB2DRange( rUpdateArea ),
                SpriteInfo( pUnchangedSprite,
                            rUpdateArea,
                            false ) );
        }
    }
 
#if OSL_DEBUG_LEVEL > 0
    static bool impIsEqualB2DRange(const basegfx::B2DRange& rRangeA, const basegfx::B2DRange& rRangeB, double fSmallValue)
    {
        return fabs(rRangeB.getMinX() - rRangeA.getMinX()) <= fSmallValue
            && fabs(rRangeB.getMinY() - rRangeA.getMinY()) <= fSmallValue
            && fabs(rRangeB.getMaxX() - rRangeA.getMaxX()) <= fSmallValue
            && fabs(rRangeB.getMaxY() - rRangeA.getMaxY()) <= fSmallValue;
    }
 
    static bool impIsEqualB2DVector(const basegfx::B2DVector& rVecA, const basegfx::B2DVector& rVecB, double fSmallValue)
    {
        return fabs(rVecB.getX() - rVecA.getX()) <= fSmallValue
            && fabs(rVecB.getY() - rVecA.getY()) <= fSmallValue;
    }
#endif
 
    bool SpriteRedrawManager::isAreaUpdateScroll( ::basegfx::B2DRectangle&  o_rMoveStart,
                                                  ::basegfx::B2DRectangle&  o_rMoveEnd,
                                                  const UpdateArea&         rUpdateArea,
                                                  std::size_t             nNumSprites ) const
    {
        // check for a solitary move, which consists of exactly two
        // pure-move entries, the first with valid, the second with
        // invalid sprite (see SpriteTracer::commit()).  Note that we
        // cannot simply store some flag in SpriteTracer::commit()
        // above and just check that here, since during the connected
        // range calculations, other sprites might get merged into the
        // same region (thus spoiling the scrolling move
        // optimization).
        if( nNumSprites != 2 )
            return false;
 
        const SpriteConnectedRanges::ComponentListType::const_iterator aFirst(
            rUpdateArea.maComponentList.begin() );
        SpriteConnectedRanges::ComponentListType::const_iterator aSecond(
            aFirst );
        ++aSecond;
 
        if( !aFirst->second.isPureMove() ||
            !aSecond->second.isPureMove() ||
            !aFirst->second.getSprite().is() ||
            // use _true_ update area, not the rounded version
            !aFirst->second.getSprite()->isAreaUpdateOpaque( aFirst->second.getUpdateArea() ) ||
            aSecond->second.getSprite().is() )
        {
            // either no move update, or incorrect sprite, or sprite
            // content not fully opaque over update region.
            return false;
        }
 
        o_rMoveStart      = aSecond->second.getUpdateArea();
        o_rMoveEnd        = aFirst->second.getUpdateArea();
 
#if OSL_DEBUG_LEVEL > 0
        ::basegfx::B2DRectangle aTotalBounds( o_rMoveStart );
        aTotalBounds.expand( o_rMoveEnd );
 
        SAL_WARN_IF(!impIsEqualB2DRange(rUpdateArea.maTotalBounds, basegfx::unotools::b2DSurroundingIntegerRangeFromB2DRange(aTotalBounds), 0.5),
            "canvas",
            "SpriteRedrawManager::isAreaUpdateScroll(): sprite area and total area mismatch");
        SAL_WARN_IF(!impIsEqualB2DVector(o_rMoveStart.getRange(), o_rMoveEnd.getRange(), 0.5),
            "canvas",
            "SpriteRedrawManager::isAreaUpdateScroll(): scroll start and end area have mismatching size");
#endif
 
        return true;
    }
 
    bool SpriteRedrawManager::isAreaUpdateNotOpaque( const ::basegfx::B2DRectangle& rUpdateRect,
                                                     const AreaComponent&           rComponent ) const
    {
        const Sprite::Reference& pAffectedSprite( rComponent.second.getSprite() );
 
        if( !pAffectedSprite.is() )
            return true; // no sprite, no opaque update!
 
        return !pAffectedSprite->isAreaUpdateOpaque( rUpdateRect );
    }
 
    bool SpriteRedrawManager::isAreaUpdateOpaque( const UpdateArea& rUpdateArea,
                                                  std::size_t     nNumSprites ) const
    {
        // check whether the sprites in the update area's list will
        // fully cover the given area _and_ do that in an opaque way
        // (i.e. no alpha, no non-rectangular sprite content).
 
        // TODO(P1): Come up with a smarter early-exit criterion here
        // (though, I think, the case that _lots_ of sprites _fully_
        // cover a rectangular area _without_ any holes is extremely
        // improbable)
 
        // avoid checking large number of sprites (and probably fail,
        // anyway). Note: the case nNumSprites < 1 should normally not
        // happen, as handleArea() calls backgroundPaint() then.
        if( nNumSprites > 3 || nNumSprites < 1 )
            return false;
 
        // now, calc the _true_ update area, by merging all sprite's
        // true update areas into one rectangle
        ::basegfx::B2DRange aTrueArea( rUpdateArea.maComponentList.begin()->second.getUpdateArea() );
        for( const auto& rArea : rUpdateArea.maComponentList )
            aTrueArea.expand(rArea.second.getUpdateArea());
 
        const SpriteConnectedRanges::ComponentListType::const_iterator aEnd(
            rUpdateArea.maComponentList.end() );
 
        // and check whether _any_ of the sprites tells that its area
        // update will not be opaque.
        return std::none_of( rUpdateArea.maComponentList.begin(),
                                aEnd,
                                [&aTrueArea, this]( const std::pair< ::basegfx::B2DRange, SpriteInfo >& cp )
                                { return this->isAreaUpdateNotOpaque(aTrueArea, cp); } );
    }
 
    bool SpriteRedrawManager::areSpritesChanged( const UpdateArea& rUpdateArea ) const
    {
        // check whether SpriteInfo::needsUpdate returns false for
        // all elements of this area's contained sprites
 
        // if not a single changed sprite found - just ignore this
        // component (return false)
        const SpriteConnectedRanges::ComponentListType::const_iterator aEnd(
            rUpdateArea.maComponentList.end() );
        return std::any_of( rUpdateArea.maComponentList.begin(),
                                aEnd,
                                []( const std::pair< ::basegfx::B2DRange, SpriteInfo >& cp )
                                { return cp.second.needsUpdate(); } );
    }
 
    SpriteRedrawManager::SpriteRedrawManager()
    {
    }
 
    void SpriteRedrawManager::disposing()
    {
        // drop all references
        maChangeRecords.clear();
 
        // dispose all sprites - the spritecanvas, and by delegation,
        // this object, is the owner of the sprites. After all, a
        // sprite without a canvas to render into makes not terribly
        // much sense.
        for( const auto& rCurr : boost::adaptors::reverse(maSprites) )
            rCurr->dispose();
 
        maSprites.clear();
    }
 
    void SpriteRedrawManager::clearChangeRecords()
    {
        maChangeRecords.clear();
    }
 
    void SpriteRedrawManager::showSprite( const Sprite::Reference& rSprite )
    {
        maSprites.push_back( rSprite );
    }
 
    void SpriteRedrawManager::hideSprite( const Sprite::Reference& rSprite )
    {
        maSprites.erase(std::remove(maSprites.begin(), maSprites.end(), rSprite), maSprites.end());
    }
 
    void SpriteRedrawManager::moveSprite( const Sprite::Reference&      rSprite,
                                          const ::basegfx::B2DPoint&    rOldPos,
                                          const ::basegfx::B2DPoint&    rNewPos,
                                          const ::basegfx::B2DVector&   rSpriteSize )
    {
        maChangeRecords.emplace_back( rSprite,
                                      rOldPos,
                                      rNewPos,
                                      rSpriteSize );
    }
 
    void SpriteRedrawManager::updateSprite( const Sprite::Reference&    rSprite,
                                            const ::basegfx::B2DPoint&  rPos,
                                            const ::basegfx::B2DRange&  rUpdateArea )
    {
        maChangeRecords.emplace_back( rSprite,
                                      rPos,
                                      rUpdateArea );
    }
 
}
 
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