qwt_plot_spectrogram.cpp

Go to the documentation of this file.

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#include "qwt_plot_spectrogram.h"
#include "qwt_painter.h"
#include "qwt_interval.h"
#include "qwt_scale_map.h"
#include "qwt_color_map.h"
#include <qimage.h>
#include <qpen.h>
#include <qpainter.h>
#include <qmath.h>
#include <qalgorithms.h>
#include <qthread.h>
#include <qfuture.h>
#include <qtconcurrentrun.h>

#define DEBUG_RENDER 0

#if DEBUG_RENDER
#include <QElapsedTimer>
#endif

static inline bool qwtIsNaN( double d )
{   
    // qt_is_nan is private header and qIsNaN is not inlined
    // so we need these code here too
    
    const uchar *ch = (const uchar *)&d;
    if ( QSysInfo::ByteOrder == QSysInfo::BigEndian )
    {   
        return (ch[0] & 0x7f) == 0x7f && ch[1] > 0xf0;
    } 
    else
    {   
        return (ch[7] & 0x7f) == 0x7f && ch[6] > 0xf0;
    }
}

class QwtPlotSpectrogram::PrivateData
{
public:
    PrivateData():
        data( NULL ),
        maxRGBColorTableSize( 0 )
    {
        colorMap = new QwtLinearColorMap();
        displayMode = ImageMode;

        conrecFlags = QwtRasterData::IgnoreAllVerticesOnLevel;
#if 0
        conrecFlags |= QwtRasterData::IgnoreOutOfRange;
#endif
    }
    ~PrivateData()
    {
        delete data;
        delete colorMap;
    }

    void updateColorTable()
    {
        if ( colorMap->format() == QwtColorMap::Indexed )
        {
            colorTable = colorMap->colorTable256();
        }
        else
        {
            if ( maxRGBColorTableSize == 0 )
                colorTable.clear();
            else
                colorTable = colorMap->colorTable( maxRGBColorTableSize );
        }
    }

    QwtRasterData *data;
    QwtColorMap *colorMap;
    DisplayModes displayMode;

    QList<double> contourLevels;
    QPen defaultContourPen;
    QwtRasterData::ConrecFlags conrecFlags;

    int maxRGBColorTableSize;
    QVector<QRgb> colorTable;
};

QwtPlotSpectrogram::QwtPlotSpectrogram( const QString &title ):
    QwtPlotRasterItem( title )
{
    d_data = new PrivateData();

    setItemAttribute( QwtPlotItem::AutoScale, true );
    setItemAttribute( QwtPlotItem::Legend, false );

    setZ( 8.0 );
}

QwtPlotSpectrogram::~QwtPlotSpectrogram()
{
    delete d_data;
}

int QwtPlotSpectrogram::rtti() const
{
    return QwtPlotItem::Rtti_PlotSpectrogram;
}

void QwtPlotSpectrogram::setDisplayMode( DisplayMode mode, bool on )
{
    if ( on != bool( mode & d_data->displayMode ) )
    {
        if ( on )
            d_data->displayMode |= mode;
        else
            d_data->displayMode &= ~mode;
    }

    legendChanged();
    itemChanged();
}

bool QwtPlotSpectrogram::testDisplayMode( DisplayMode mode ) const
{
    return ( d_data->displayMode & mode );
}

void QwtPlotSpectrogram::setColorMap( QwtColorMap *colorMap )
{
    if ( colorMap == NULL )
        return;

    if ( colorMap != d_data->colorMap )
    {
        delete d_data->colorMap;
        d_data->colorMap = colorMap;
    }

    d_data->updateColorTable();

    invalidateCache();

    legendChanged();
    itemChanged();
}

const QwtColorMap *QwtPlotSpectrogram::colorMap() const
{
    return d_data->colorMap;
}

void QwtPlotSpectrogram::setMaxRGBTableSize( int numColors )
{
    numColors = qMax( numColors, 0 );
    if ( numColors != d_data->maxRGBColorTableSize )
    {
        d_data->maxRGBColorTableSize = numColors;
        d_data->updateColorTable();
        invalidateCache();
    }
}

int QwtPlotSpectrogram::maxRGBTableSize() const
{
    return d_data->maxRGBColorTableSize;
}

void QwtPlotSpectrogram::setDefaultContourPen( 
    const QColor &color, qreal width, Qt::PenStyle style )
{   
    setDefaultContourPen( QPen( color, width, style ) );
}

void QwtPlotSpectrogram::setDefaultContourPen( const QPen &pen )
{
    if ( pen != d_data->defaultContourPen )
    {
        d_data->defaultContourPen = pen;

        legendChanged();
        itemChanged();
    }
}

QPen QwtPlotSpectrogram::defaultContourPen() const
{
    return d_data->defaultContourPen;
}

QPen QwtPlotSpectrogram::contourPen( double level ) const
{
    if ( d_data->data == NULL || d_data->colorMap == NULL )
        return QPen();

    const QwtInterval intensityRange = d_data->data->interval(Qt::ZAxis);
    const QColor c( d_data->colorMap->rgb( intensityRange, level ) );

    return QPen( c );
}

void QwtPlotSpectrogram::setConrecFlag(
    QwtRasterData::ConrecFlag flag, bool on )
{
    if ( bool( d_data->conrecFlags & flag ) == on )
        return;

    if ( on )
        d_data->conrecFlags |= flag;
    else
        d_data->conrecFlags &= ~flag;

    itemChanged();
}

bool QwtPlotSpectrogram::testConrecFlag(
    QwtRasterData::ConrecFlag flag ) const
{
    return d_data->conrecFlags & flag;
}

void QwtPlotSpectrogram::setContourLevels( const QList<double> &levels )
{
    d_data->contourLevels = levels;
    qSort( d_data->contourLevels );

    legendChanged();
    itemChanged();
}

QList<double> QwtPlotSpectrogram::contourLevels() const
{
    return d_data->contourLevels;
}

void QwtPlotSpectrogram::setData( QwtRasterData *data )
{
    if ( data != d_data->data )
    {
        delete d_data->data;
        d_data->data = data;

        invalidateCache();
        itemChanged();
    }
}

const QwtRasterData *QwtPlotSpectrogram::data() const
{
    return d_data->data;
}

QwtRasterData *QwtPlotSpectrogram::data()
{
    return d_data->data;
}

QwtInterval QwtPlotSpectrogram::interval(Qt::Axis axis) const
{
    if ( d_data->data == NULL )
        return QwtInterval();

    return d_data->data->interval( axis );
}

QRectF QwtPlotSpectrogram::pixelHint( const QRectF &area ) const
{
    if ( d_data->data == NULL )
        return QRectF();

    return d_data->data->pixelHint( area );
}

QImage QwtPlotSpectrogram::renderImage(
    const QwtScaleMap &xMap, const QwtScaleMap &yMap,
    const QRectF &area, const QSize &imageSize ) const
{
    if ( imageSize.isEmpty() || d_data->data == NULL 
        || d_data->colorMap == NULL )
    {
        return QImage();
    }

    const QwtInterval intensityRange = d_data->data->interval( Qt::ZAxis );
    if ( !intensityRange.isValid() )
        return QImage();

    const QImage::Format format = ( d_data->colorMap->format() == QwtColorMap::RGB )
        ? QImage::Format_ARGB32 : QImage::Format_Indexed8;

    QImage image( imageSize, format );

    if ( d_data->colorMap->format() == QwtColorMap::Indexed )
        image.setColorTable( d_data->colorMap->colorTable256() );

    d_data->data->initRaster( area, image.size() );

#if DEBUG_RENDER
    QElapsedTimer time;
    time.start();
#endif

#if !defined(QT_NO_QFUTURE)
    uint numThreads = renderThreadCount();

    if ( numThreads <= 0 )
        numThreads = QThread::idealThreadCount();

    if ( numThreads <= 0 )
        numThreads = 1;

    const int numRows = imageSize.height() / numThreads;

    QVector< QFuture<void> > futures;
    futures.reserve( numThreads - 1 );

    for ( uint i = 0; i < numThreads; i++ )
    {
        QRect tile( 0, i * numRows, image.width(), numRows );
        if ( i == numThreads - 1 )
        {
            tile.setHeight( image.height() - i * numRows );
            renderTile( xMap, yMap, tile, &image );
        }
        else
        {
            futures += QtConcurrent::run(
                this, &QwtPlotSpectrogram::renderTile,
                xMap, yMap, tile, &image );
        }
    }
    for ( int i = 0; i < futures.size(); i++ )
        futures[i].waitForFinished();

#else 
    const QRect tile( 0, 0, image.width(), image.height() );
    renderTile( xMap, yMap, tile, &image );
#endif

#if DEBUG_RENDER
    const qint64 elapsed = time.elapsed();
    qDebug() << "renderImage" << imageSize << elapsed;
#endif

    d_data->data->discardRaster();

    return image;
}

void QwtPlotSpectrogram::renderTile(
    const QwtScaleMap &xMap, const QwtScaleMap &yMap,
    const QRect &tile, QImage *image ) const
{
    const QwtInterval range = d_data->data->interval( Qt::ZAxis );
    if ( range.width() <= 0.0 )
        return;

    const bool hasGaps = !d_data->data->testAttribute( QwtRasterData::WithoutGaps );

    if ( d_data->colorMap->format() == QwtColorMap::RGB )
    {
        const int numColors = d_data->colorTable.size();
        const QRgb *rgbTable = d_data->colorTable.constData();
        const QwtColorMap *colorMap = d_data->colorMap;

        for ( int y = tile.top(); y <= tile.bottom(); y++ )
        {
            const double ty = yMap.invTransform( y );

            QRgb *line = reinterpret_cast<QRgb *>( image->scanLine( y ) );
            line += tile.left();

            for ( int x = tile.left(); x <= tile.right(); x++ )
            {
                const double tx = xMap.invTransform( x );

                const double value = d_data->data->value( tx, ty );

                if ( hasGaps && qwtIsNaN( value ) )
                {
                    *line++ = 0u;
                }
                else if ( numColors == 0 )
                {
                    *line++ = colorMap->rgb( range, value );
                }
                else
                {
                    const uint index = colorMap->colorIndex( numColors, range, value );
                    *line++ = rgbTable[index];
                }
            }
        }
    }
    else if ( d_data->colorMap->format() == QwtColorMap::Indexed )
    {
        for ( int y = tile.top(); y <= tile.bottom(); y++ )
        {
            const double ty = yMap.invTransform( y );

            unsigned char *line = image->scanLine( y );
            line += tile.left();

            for ( int x = tile.left(); x <= tile.right(); x++ )
            {
                const double tx = xMap.invTransform( x );

                const double value = d_data->data->value( tx, ty );

                if ( hasGaps && qwtIsNaN( value ) )
                {
                    *line++ = 0;
                }
                else
                {
                    const uint index = d_data->colorMap->colorIndex( 256, range, value );
                    *line++ = static_cast<unsigned char>( index );
                }
            }
        }
    }
}

QSize QwtPlotSpectrogram::contourRasterSize( 
    const QRectF &area, const QRect &rect ) const
{
    QSize raster = rect.size() / 2;

    const QRectF pixelRect = pixelHint( area );
    if ( !pixelRect.isEmpty() )
    {
        const QSize res( qCeil( rect.width() / pixelRect.width() ),
            qCeil( rect.height() / pixelRect.height() ) );
        raster = raster.boundedTo( res );
    }

    return raster;
}

QwtRasterData::ContourLines QwtPlotSpectrogram::renderContourLines(
    const QRectF &rect, const QSize &raster ) const
{
    if ( d_data->data == NULL )
        return QwtRasterData::ContourLines();

    return d_data->data->contourLines( rect, raster,
        d_data->contourLevels, d_data->conrecFlags );
}

void QwtPlotSpectrogram::drawContourLines( QPainter *painter,
        const QwtScaleMap &xMap, const QwtScaleMap &yMap,
        const QwtRasterData::ContourLines &contourLines ) const
{
    if ( d_data->data == NULL )
        return;

    const int numLevels = d_data->contourLevels.size();
    for ( int l = 0; l < numLevels; l++ )
    {
        const double level = d_data->contourLevels[l];

        QPen pen = defaultContourPen();
        if ( pen.style() == Qt::NoPen )
            pen = contourPen( level );

        if ( pen.style() == Qt::NoPen )
            continue;

        painter->setPen( pen );

        const QPolygonF &lines = contourLines[level];
        for ( int i = 0; i < lines.size(); i += 2 )
        {
            const QPointF p1( xMap.transform( lines[i].x() ),
                yMap.transform( lines[i].y() ) );
            const QPointF p2( xMap.transform( lines[i+1].x() ),
                yMap.transform( lines[i+1].y() ) );

            QwtPainter::drawLine( painter, p1, p2 );
        }
    }
}

void QwtPlotSpectrogram::draw( QPainter *painter,
    const QwtScaleMap &xMap, const QwtScaleMap &yMap,
    const QRectF &canvasRect ) const
{
    if ( d_data->displayMode & ImageMode )
        QwtPlotRasterItem::draw( painter, xMap, yMap, canvasRect );

    if ( d_data->displayMode & ContourMode )
    {
        // Add some pixels at the borders
        const int margin = 2;
        QRectF rasterRect( canvasRect.x() - margin, canvasRect.y() - margin,
            canvasRect.width() + 2 * margin, canvasRect.height() + 2 * margin );

        QRectF area = QwtScaleMap::invTransform( xMap, yMap, rasterRect );

        const QRectF br = boundingRect();
        if ( br.isValid() )
        {
            area &= br;
            if ( area.isEmpty() )
                return;

            rasterRect = QwtScaleMap::transform( xMap, yMap, area );
        }

        QSize raster = contourRasterSize( area, rasterRect.toRect() );
        raster = raster.boundedTo( rasterRect.toRect().size() );
        if ( raster.isValid() )
        {
            const QwtRasterData::ContourLines lines =
                renderContourLines( area, raster );

            drawContourLines( painter, xMap, yMap, lines );
        }
    }
}