qwt_plot_spectrogram.cpp

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/* -*- 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 <qimage.h>
#include <qpen.h>
#include <qpainter.h>
#include "qwt_painter.h"
#include "qwt_double_interval.h"
#include "qwt_scale_map.h"
#include "qwt_color_map.h"
#include "qwt_plot_spectrogram.h"

#if QT_VERSION < 0x040000
typedef QValueVector<QRgb> QwtColorTable;
#else
typedef QVector<QRgb> QwtColorTable;
#endif

class QwtPlotSpectrogramImage: public QImage
{
  // This class hides some Qt3/Qt4 API differences
public:
    QwtPlotSpectrogramImage(const QSize &size, QwtColorMap::Format format):
#if QT_VERSION < 0x040000
        QImage(size, format == QwtColorMap::RGB ? 32 : 8)
#else
        QImage(size, format == QwtColorMap::RGB
            ? QImage::Format_ARGB32 : QImage::Format_Indexed8 )
#endif
    {
    }

    QwtPlotSpectrogramImage(const QImage &other):
        QImage(other)
    {
    }

    void initColorTable(const QImage& other)
    {
#if QT_VERSION < 0x040000
        const unsigned int numColors = other.numColors();

        setNumColors(numColors);
        for ( unsigned int i = 0; i < numColors; i++ )
            setColor(i, other.color(i));
#else
        setColorTable(other.colorTable());
#endif
    }

#if QT_VERSION < 0x040000

    void setColorTable(const QwtColorTable &colorTable)
    {
        setNumColors(colorTable.size());
        for ( unsigned int i = 0; i < colorTable.size(); i++ )
            setColor(i, colorTable[i]);
    }

    QwtColorTable colorTable() const
    {
        QwtColorTable table(numColors());
        for ( int i = 0; i < numColors(); i++ )
            table[i] = color(i);

        return table;
    }
#endif
};

class QwtPlotSpectrogram::PrivateData
{
public:
    class DummyData: public QwtRasterData
    {
    public:
        virtual QwtRasterData *copy() const
        {
            return new DummyData();
        }

        virtual double value(double, double) const
        {
            return 0.0;
        }

        virtual QwtDoubleInterval range() const
        {
            return QwtDoubleInterval(0.0, 1.0);
        }
    };

    PrivateData()
    {
        data = new DummyData();
        colorMap = new QwtLinearColorMap();
        displayMode = ImageMode;

        conrecAttributes = QwtRasterData::IgnoreAllVerticesOnLevel;
        conrecAttributes |= QwtRasterData::IgnoreOutOfRange;
    }
    ~PrivateData()
    {
        delete data;
        delete colorMap;
    }

    QwtRasterData *data;
    QwtColorMap *colorMap;
    int displayMode;

    QwtValueList contourLevels;
    QPen defaultContourPen;
    int conrecAttributes;
};

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;
    }

    itemChanged();
}

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

void QwtPlotSpectrogram::setColorMap(const QwtColorMap &colorMap)
{
    delete d_data->colorMap;
    d_data->colorMap = colorMap.copy();

    invalidateCache();
    itemChanged();
}

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

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

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

QPen QwtPlotSpectrogram::contourPen(double level) const
{
    const QwtDoubleInterval intensityRange = d_data->data->range();
    const QColor c(d_data->colorMap->rgb(intensityRange, level));

    return QPen(c);
}

void QwtPlotSpectrogram::setConrecAttribute(
    QwtRasterData::ConrecAttribute attribute, bool on)
{
    if ( bool(d_data->conrecAttributes & attribute) == on )
        return;

    if ( on )
        d_data->conrecAttributes |= attribute;
    else
        d_data->conrecAttributes &= ~attribute;

    itemChanged();
}

bool QwtPlotSpectrogram::testConrecAttribute(
    QwtRasterData::ConrecAttribute attribute) const
{   
    return d_data->conrecAttributes & attribute;
}

void QwtPlotSpectrogram::setContourLevels(const QwtValueList &levels)
{
    d_data->contourLevels = levels;
#if QT_VERSION >= 0x040000
    qSort(d_data->contourLevels);
#else
    qHeapSort(d_data->contourLevels);
#endif
    itemChanged();
}

QwtValueList QwtPlotSpectrogram::contourLevels() const
{
    return d_data->contourLevels;
}

void QwtPlotSpectrogram::setData(const QwtRasterData &data)
{
    delete d_data->data;
    d_data->data = data.copy();

    invalidateCache();
    itemChanged();
}

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

QwtDoubleRect QwtPlotSpectrogram::boundingRect() const
{
    return d_data->data->boundingRect();
}

QSize QwtPlotSpectrogram::rasterHint(const QwtDoubleRect &rect) const
{
    return d_data->data->rasterHint(rect);
}

QImage QwtPlotSpectrogram::renderImage(
    const QwtScaleMap &xMap, const QwtScaleMap &yMap, 
    const QwtDoubleRect &area) const
{
    if ( area.isEmpty() )
        return QImage();

    QRect rect = transform(xMap, yMap, area);

    QwtScaleMap xxMap = xMap;
    QwtScaleMap yyMap = yMap;

    const QSize res = d_data->data->rasterHint(area);
    if ( res.isValid() )
    {
        /*
          It is useless to render an image with a higher resolution
          than the data offers. Of course someone will have to
          scale this image later into the size of the given rect, but f.e.
          in case of postscript this will done on the printer.
         */
        rect.setSize(rect.size().boundedTo(res));

        int px1 = rect.x();
        int px2 = rect.x() + rect.width();
        if ( xMap.p1() > xMap.p2() )
            qSwap(px1, px2);

        double sx1 = area.x();
        double sx2 = area.x() + area.width();
        if ( xMap.s1() > xMap.s2() )
            qSwap(sx1, sx2);

        int py1 = rect.y();
        int py2 = rect.y() + rect.height();
        if ( yMap.p1() > yMap.p2() )
            qSwap(py1, py2);

        double sy1 = area.y();
        double sy2 = area.y() + area.height();
        if ( yMap.s1() > yMap.s2() )
            qSwap(sy1, sy2);

        xxMap.setPaintInterval(px1, px2);
        xxMap.setScaleInterval(sx1, sx2);
        yyMap.setPaintInterval(py1, py2);
        yyMap.setScaleInterval(sy1, sy2); 
    }

    QwtPlotSpectrogramImage image(rect.size(), d_data->colorMap->format());

    const QwtDoubleInterval intensityRange = d_data->data->range();
    if ( !intensityRange.isValid() )
        return image;

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

    if ( d_data->colorMap->format() == QwtColorMap::RGB )
    {
        for ( int y = rect.top(); y <= rect.bottom(); y++ )
        {
            const double ty = yyMap.invTransform(y);

            QRgb *line = (QRgb *)image.scanLine(y - rect.top());
            for ( int x = rect.left(); x <= rect.right(); x++ )
            {
                const double tx = xxMap.invTransform(x);

                *line++ = d_data->colorMap->rgb(intensityRange,
                    d_data->data->value(tx, ty));
            }
        }
    }
    else if ( d_data->colorMap->format() == QwtColorMap::Indexed )
    {
        image.setColorTable(d_data->colorMap->colorTable(intensityRange));

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

            unsigned char *line = image.scanLine(y - rect.top());
            for ( int x = rect.left(); x <= rect.right(); x++ )
            {
                const double tx = xxMap.invTransform(x);

                *line++ = d_data->colorMap->colorIndex(intensityRange,
                    d_data->data->value(tx, ty));
            }
        }
    }

    d_data->data->discardRaster();

    // Mirror the image in case of inverted maps

    const bool hInvert = xxMap.p1() > xxMap.p2();
    const bool vInvert = yyMap.p1() < yyMap.p2();
    if ( hInvert || vInvert )
    {
#ifdef __GNUC__
#endif
#if QT_VERSION < 0x040000
        image = image.mirror(hInvert, vInvert);
#else
        image = image.mirrored(hInvert, vInvert);
#endif
    }

    return image;
}

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

    const QSize rasterHint = d_data->data->rasterHint(area);
    if ( rasterHint.isValid() )
        raster = raster.boundedTo(rasterHint);

    return raster;
}

QwtRasterData::ContourLines QwtPlotSpectrogram::renderContourLines(
    const QwtDoubleRect &rect, const QSize &raster) const
{
    return d_data->data->contourLines(rect, raster,
        d_data->contourLevels, d_data->conrecAttributes );
}

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

    const int numLevels = (int)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(QwtPainter::scaledPen(pen));

#if QT_VERSION >= 0x040000
        const QPolygonF &lines = contourLines[level];
#else
        const QwtArray<QwtDoublePoint> &lines = contourLines[level];
#endif
        for ( int i = 0; i < (int)lines.size(); i += 2 )
        {
            const QPoint p1( xMap.transform(lines[i].x()),
                yMap.transform(lines[i].y()) );
            const QPoint 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 QRect &canvasRect) const
{
    if ( d_data->displayMode & ImageMode )
        QwtPlotRasterItem::draw(painter, xMap, yMap, canvasRect);

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

        QwtDoubleRect area = invTransform(xMap, yMap, rasterRect);

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

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

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

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