pagepainter.cpp.svn-base

okular

/***************************************************************************
 *   Copyright (C) 2005 by Enrico Ros <[e-mail]>                  *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 ***************************************************************************/

// qt / kde includes
#include <qrect.h>
#include <qpainter.h>
#include <qpixmap.h>
#include <qimage.h>
#include <qapplication.h>
#include <kglobal.h>
#include <kimageeffect.h>
#include <kiconloader.h>
#include <kstaticdeleter.h>
#include <kdebug.h>

// system includes
#include <math.h>

// local includes
#include "pagepainter.h"
#include "core/area.h"
#include "core/page.h"
#include "core/annotations.h"
#include "settings.h"

static KStaticDeleter<QPixmap> sd;
QPixmap * busyPixmap = 0;

void PagePainter::paintPageOnPainter( QPainter * destPainter, const KPDFPage * page,
    int pixID, int flags, int scaledWidth, int scaledHeight, const QRect & limits )
{
    /** 1 - RETRIEVE THE 'PAGE+ID' PIXMAP OR A SIMILAR 'PAGE' ONE **/
    const QPixmap * pixmap = 0;

    // if a pixmap is present for given id, use it
    if ( page->m_pixmaps.contains( pixID ) )
        pixmap = page->m_pixmaps[ pixID ];

    // else find the closest match using pixmaps of other IDs (great optim!)
    else if ( !page->m_pixmaps.isEmpty() )
    {
        int minDistance = -1;
        QMap< int,QPixmap * >::const_iterator it = page->m_pixmaps.begin(), end = page->m_pixmaps.end();
        for ( ; it != end; ++it )
        {
            int pixWidth = (*it)->width(),
                distance = pixWidth > scaledWidth ? pixWidth - scaledWidth : scaledWidth - pixWidth;
            if ( minDistance == -1 || distance < minDistance )
            {
                pixmap = *it;
                minDistance = distance;
            }
        }
    }

    /** 1B - IF NO PIXMAP, DRAW EMPTY PAGE **/
    double pixmapRescaleRatio = pixmap ? scaledWidth / (double)pixmap->width() : -1;
    long pixmapPixels = pixmap ? (long)pixmap->width() * (long)pixmap->height() : 0;
    if ( !pixmap || pixmapRescaleRatio > 20.0 || pixmapRescaleRatio < 0.25 ||
         (scaledWidth != pixmap->width() && pixmapPixels > 6000000L) )
    {
        if ( KpdfSettings::changeColors() &&
             KpdfSettings::renderMode() == KpdfSettings::EnumRenderMode::Paper )
            destPainter->fillRect( limits, KpdfSettings::paperColor() );
        else
            destPainter->fillRect( limits, Qt::white );

        if ( !busyPixmap )
        {
            sd.setObject(busyPixmap, new QPixmap());
            *busyPixmap = KGlobal::iconLoader()->loadIcon("okular", K3Icon::NoGroup, 32, K3Icon::DefaultState, 0, true);
        }
        // draw something on the blank page: the okular icon or a cross (as a fallback)
        if ( busyPixmap && !busyPixmap->isNull() )
        {
            destPainter->drawPixmap( QPoint( 10, 10 ), *busyPixmap );
        }
        else
        {
            destPainter->setPen( Qt::gray );
            destPainter->drawLine( 0, 0, scaledWidth-1, scaledHeight-1 );
            destPainter->drawLine( 0, scaledHeight-1, scaledWidth-1, 0 );
        }
        return;
    }

    /** 2 - FIND OUT WHAT TO PAINT (Flags + Configuration + Presence) **/
    bool canDrawHighlights = (flags & Highlights) && !page->m_highlights.isEmpty();
    bool canDrawAnnotations = (flags & Annotations) && !page->m_annotations.isEmpty();
    bool enhanceLinks = (flags & EnhanceLinks) && KpdfSettings::highlightLinks();
    bool enhanceImages = (flags & EnhanceImages) && KpdfSettings::highlightImages();
    // vectors containing objects to draw
    // make this a qcolor, rect map, since we dont need 
    // to know s_id here! we are only drawing this right?
    QList< QPair<QColor, NormalizedRect *> > * bufferedHighlights = 0;
    QList< Annotation * > * bufferedAnnotations = 0;
    QList< Annotation * > * unbufferedAnnotations = 0;
    // fill up lists with visible annotation/highlight objects
    if ( canDrawHighlights || canDrawAnnotations )
    {
        // precalc normalized 'limits rect' for intersection
        double nXMin = (double)limits.left() / (double)scaledWidth,
               nXMax = (double)limits.right() / (double)scaledWidth,
               nYMin = (double)limits.top() / (double)scaledHeight,
               nYMax = (double)limits.bottom() / (double)scaledHeight;
        // append all highlights inside limits to their list
        if ( canDrawHighlights )
        {
            if ( !bufferedHighlights )
                 bufferedHighlights = new QList< QPair<QColor, NormalizedRect *>  >();
/*            else
            {*/
                
                NormalizedRect* limitRect = new NormalizedRect(nXMin, nYMin, nXMax, nYMax );
                QLinkedList< HighlightAreaRect * >::const_iterator h2It = page->m_highlights.begin(), hEnd = page->m_highlights.end();
                QList< NormalizedRect * >::const_iterator hIt;
                for ( ; h2It != hEnd; ++h2It )
                    for (hIt=(*h2It)->begin(); hIt!=(*h2It)->end(); ++hIt)
                    {
                        if ((*hIt)->intersects(limitRect))
                            bufferedHighlights->append( qMakePair((*h2It)->color,*hIt) );
                    }
                delete limitRect;
            //}
        }
        // append annotations inside limits to the un/buffered list
        if ( canDrawAnnotations )
        {
            QLinkedList< Annotation * >::const_iterator aIt = page->m_annotations.begin(), aEnd = page->m_annotations.end();
            for ( ; aIt != aEnd; ++aIt )
            {
                Annotation * ann = *aIt;
                if ( ann->boundary.intersects( nXMin, nYMin, nXMax, nYMax ) )
                {
                    Annotation::SubType type = ann->subType();
                    if ( type == Annotation::ALine || type == Annotation::AHighlight ||
                         type == Annotation::AInk  /*|| (type == Annotation::AGeom && ann->style.opacity < 0.99)*/ )
                    {
                        if ( !bufferedAnnotations )
                            bufferedAnnotations = new QList< Annotation * >();
                        bufferedAnnotations->append( ann );
                    }
                    else
                    {
                        if ( !unbufferedAnnotations )
                            unbufferedAnnotations = new QList< Annotation * >();
                        unbufferedAnnotations->append( ann );
                    }
                }
            }
        }
        // end of intersections checking
    }

    /** 3 - ENABLE BACKBUFFERING IF DIRECT IMAGE MANIPULATION IS NEEDED **/
    bool bufferAccessibility = (flags & Accessibility) && KpdfSettings::changeColors() && (KpdfSettings::renderMode() != KpdfSettings::EnumRenderMode::Paper);
    bool useBackBuffer = bufferAccessibility || bufferedHighlights || bufferedAnnotations;
    QPixmap * backPixmap = 0;
    QPainter * mixedPainter = 0;

    /** 4A -- REGULAR FLOW. PAINT PIXMAP NORMAL OR RESCALED USING GIVEN QPAINTER **/
    if ( !useBackBuffer )
    {
        // 4A.1. if size is ok, draw the page pixmap using painter
        if ( pixmap->width() == scaledWidth && pixmap->height() == scaledHeight )
            destPainter->drawPixmap( limits.topLeft(), *pixmap, limits );
        // else draw a scaled portion of the magnified pixmap
        else
        {
            QImage destImage;
            scalePixmapOnImage( destImage, pixmap, scaledWidth, scaledHeight, limits );
            destPainter->drawImage( limits.left(), limits.top(), destImage, 0, 0,
                                     limits.width(),limits.height() );
        }

        // 4A.2. active painter is the one passed to this method
        mixedPainter = destPainter;
    }
    /** 4B -- BUFFERED FLOW. IMAGE PAINTING + OPERATIONS. QPAINTER OVER PIXMAP  **/
    else
    {
        // the image over which we are going to draw
        QImage backImage;

        // 4B.1. draw the page pixmap: normal or scaled
        if ( pixmap->width() == scaledWidth && pixmap->height() == scaledHeight )
            cropPixmapOnImage( backImage, pixmap, limits );
        else
            scalePixmapOnImage( backImage, pixmap, scaledWidth, scaledHeight, limits );

        // 4B.2. modify pixmap following accessibility settings
        if ( bufferAccessibility )
        {
            switch ( KpdfSettings::renderMode() )
            {
                case KpdfSettings::EnumRenderMode::Inverted:
                    // Invert image pixels using QImage internal function
                    backImage.invertPixels(QImage::InvertRgb);
                    break;
                case KpdfSettings::EnumRenderMode::Recolor:
                    // Recolor image using KImageEffect::flatten with dither:0
                    KImageEffect::flatten( backImage, KpdfSettings::recolorForeground(), KpdfSettings::recolorBackground() );
                    break;
                case KpdfSettings::EnumRenderMode::BlackWhite:
                    // Manual Gray and Contrast
                    unsigned int * data = (unsigned int *)backImage.bits();
                    int val, pixels = backImage.width() * backImage.height(),
                        con = KpdfSettings::bWContrast(), thr = 255 - KpdfSettings::bWThreshold();
                    for( int i = 0; i < pixels; ++i )
                    {
                        val = qGray( data[i] );
                        if ( val > thr )
                            val = 128 + (127 * (val - thr)) / (255 - thr);
                        else if ( val < thr )
                            val = (128 * val) / thr;
                        if ( con > 2 )
                        {
                            val = con * ( val - thr ) / 2 + thr;
                            if ( val > 255 )
                                val = 255;
                            else if ( val < 0 )
                                val = 0;
                        }
                        data[i] = qRgba( val, val, val, 255 );
                    }
                    break;
            }
        }
        // 4B.3. highlight rects in page
        if ( bufferedHighlights )
        {
            // draw highlights that are inside the 'limits' paint region
            QList< QPair<QColor, NormalizedRect *> >::const_iterator hIt = bufferedHighlights->begin(), hEnd = bufferedHighlights->end();
            for ( ; hIt != hEnd; ++hIt )
            {
                NormalizedRect * r = (*hIt).second;
                // find out the rect to highlight on pixmap
                QRect highlightRect = r->geometry( scaledWidth, scaledHeight ).intersect( limits );
                highlightRect.translate( -limits.left(), -limits.top() );

                // highlight composition (product: highlight color * destcolor)
                unsigned int * data = (unsigned int *)backImage.bits();
                int val, newR, newG, newB,
                    rh = (*hIt).first.red(),
                    gh = (*hIt).first.green(),
                    bh = (*hIt).first.blue(),
                    offset = highlightRect.top() * backImage.width();
                for( int y = highlightRect.top(); y <= highlightRect.bottom(); ++y )
                {
                    for( int x = highlightRect.left(); x <= highlightRect.right(); ++x )
                    {
                        val = data[ x + offset ];
                        newR = (qRed(val) * rh) / 255;
                        newG = (qGreen(val) * gh) / 255;
                        newB = (qBlue(val) * bh) / 255;
                        data[ x + offset ] = qRgba( newR, newG, newB, 255 );
                    }
                    offset += backImage.width();
                }