annotate layer/SpectrumLayer.cpp @ 1127:9fb8dfd7ce4c spectrogram-minor-refactor

Fix threshold in spectrogram -- it wasn't working in the last release.
There is a new protocol for this. Formerly the threshold parameter had a
range from -50dB to 0 with the default at -50, and -50 treated internally
as "no threshold". However, there was a hardcoded, hidden internal threshold
for spectrogram colour mapping at -80dB with anything below this being rounded
to zero. Now the threshold parameter has range -81 to -1 with the default
at -80, -81 is treated internally as "no threshold", and there is no hidden
internal threshold. So the default behaviour is the same as before, an
effective -80dB threshold, but it is now possible to change this in both
directions. Sessions reloaded from prior versions may look slightly different
because, if the session says there should be no threshold, there will now
actually be no threshold instead of having the hidden internal one.

Still need to do something in the UI to make it apparent that the -81dB
setting removes the threshold entirely. This is at least no worse than the
previous, also obscured, magic -50dB setting.

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006-2007 QMUL.
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

#include "SpectrumLayer.h"

#include "data/model/FFTModel.h"
#include "view/View.h"
#include "base/AudioLevel.h"
#include "base/Preferences.h"
#include "base/RangeMapper.h"
#include "base/Pitch.h"

#include "ColourMapper.h"
#include "PaintAssistant.h"

#include <QPainter>
#include <QTextStream>


SpectrumLayer::SpectrumLayer() :
    m_originModel(0),
    m_channel(-1),
    m_channelSet(false),
    m_windowSize(4096),
    m_windowType(HanningWindow),
    m_windowHopLevel(3),
    m_showPeaks(false),
    m_newFFTNeeded(true)
{
    Preferences *prefs = Preferences::getInstance();
    connect(prefs, SIGNAL(propertyChanged(PropertyContainer::PropertyName)),
            this, SLOT(preferenceChanged(PropertyContainer::PropertyName)));
    setWindowType(prefs->getWindowType());

    setBinScale(LogBins);
}

SpectrumLayer::~SpectrumLayer()
{
    Model *m = const_cast<Model *>
        (static_cast<const Model *>(m_sliceableModel));
    if (m) m->aboutToDelete();
    m_sliceableModel = 0;
    delete m;
}

void
SpectrumLayer::setModel(DenseTimeValueModel *model)
{
    SVDEBUG << "SpectrumLayer::setModel(" << model << ") from " << m_originModel << endl;
    
    if (m_originModel == model) return;

    m_originModel = model;

    if (m_sliceableModel) {
        Model *m = const_cast<Model *>
            (static_cast<const Model *>(m_sliceableModel));
        m->aboutToDelete();
        setSliceableModel(0);
        delete m;
    }

    m_newFFTNeeded = true;

    emit layerParametersChanged();
}

void
SpectrumLayer::setChannel(int channel)
{
    SVDEBUG << "SpectrumLayer::setChannel(" << channel << ") from " << m_channel << endl;
    
    m_channelSet = true;
    
    if (m_channel == channel) return;

    m_channel = channel;

    m_newFFTNeeded = true;

    emit layerParametersChanged();
}

void
SpectrumLayer::setupFFT()
{
    if (m_sliceableModel) {
        Model *m = const_cast<Model *>
            (static_cast<const Model *>(m_sliceableModel));
        m->aboutToDelete();
        setSliceableModel(0);
        delete m;
    }

    if (!m_originModel) {
        return;
    }

    FFTModel *newFFT = new FFTModel(m_originModel,
                                    m_channel,
                                    m_windowType,
                                    m_windowSize,
                                    getWindowIncrement(),
                                    m_windowSize);

    setSliceableModel(newFFT);

    m_biasCurve.clear();
    for (int i = 0; i < m_windowSize; ++i) {
        m_biasCurve.push_back(1.f / (float(m_windowSize)/2.f));
    }

    m_newFFTNeeded = false;
}

Layer::PropertyList
SpectrumLayer::getProperties() const
{
    PropertyList list = SliceLayer::getProperties();
    list.push_back("Window Size");
    list.push_back("Window Increment");
    list.push_back("Show Peak Frequencies");
    return list;
}

QString
SpectrumLayer::getPropertyLabel(const PropertyName &name) const
{
    if (name == "Window Size") return tr("Window Size");
    if (name == "Window Increment") return tr("Window Overlap");
    if (name == "Show Peak Frequencies") return tr("Show Peak Frequencies");
    return SliceLayer::getPropertyLabel(name);
}

QString
SpectrumLayer::getPropertyIconName(const PropertyName &name) const
{
    if (name == "Show Peak Frequencies") return "show-peaks";
    return SliceLayer::getPropertyIconName(name);
}

Layer::PropertyType
SpectrumLayer::getPropertyType(const PropertyName &name) const
{
    if (name == "Window Size") return ValueProperty;
    if (name == "Window Increment") return ValueProperty;
    if (name == "Show Peak Frequencies") return ToggleProperty;
    return SliceLayer::getPropertyType(name);
}

QString
SpectrumLayer::getPropertyGroupName(const PropertyName &name) const
{
    if (name == "Window Size" ||
	name == "Window Increment") return tr("Window");
    if (name == "Show Peak Frequencies") return tr("Bins");
    return SliceLayer::getPropertyGroupName(name);
}

int
SpectrumLayer::getPropertyRangeAndValue(const PropertyName &name,
                                        int *min, int *max, int *deflt) const
{
    int val = 0;

    int garbage0, garbage1, garbage2;
    if (!min) min = &garbage0;
    if (!max) max = &garbage1;
    if (!deflt) deflt = &garbage2;

    if (name == "Window Size") {

	*min = 0;
	*max = 15;
        *deflt = 5;
	
	val = 0;
	int ws = m_windowSize;
	while (ws > 32) { ws >>= 1; val ++; }

    } else if (name == "Window Increment") {
	
	*min = 0;
	*max = 5;
        *deflt = 2;
	
        val = m_windowHopLevel;
    
    } else if (name == "Show Peak Frequencies") {

        return m_showPeaks ? 1 : 0;

    } else {

        val = SliceLayer::getPropertyRangeAndValue(name, min, max, deflt);
    }

    return val;
}

QString
SpectrumLayer::getPropertyValueLabel(const PropertyName &name,
				    int value) const
{
    if (name == "Window Size") {
	return QString("%1").arg(32 << value);
    }
    if (name == "Window Increment") {
	switch (value) {
	default:
	case 0: return tr("None");
	case 1: return tr("25 %");
	case 2: return tr("50 %");
	case 3: return tr("75 %");
	case 4: return tr("87.5 %");
	case 5: return tr("93.75 %");
	}
    }
    return SliceLayer::getPropertyValueLabel(name, value);
}

RangeMapper *
SpectrumLayer::getNewPropertyRangeMapper(const PropertyName &name) const
{
    return SliceLayer::getNewPropertyRangeMapper(name);
}

void
SpectrumLayer::setProperty(const PropertyName &name, int value)
{
    if (name == "Window Size") {
	setWindowSize(32 << value);
    } else if (name == "Window Increment") {
        setWindowHopLevel(value);
    } else if (name == "Show Peak Frequencies") {
        setShowPeaks(value ? true : false);
    } else {
        SliceLayer::setProperty(name, value);
    }
}

void
SpectrumLayer::setWindowSize(int ws)
{
    if (m_windowSize == ws) return;
    m_windowSize = ws;
    m_newFFTNeeded = true;
    emit layerParametersChanged();
}

void
SpectrumLayer::setWindowHopLevel(int v)
{
    if (m_windowHopLevel == v) return;
    m_windowHopLevel = v;
    m_newFFTNeeded = true;
    emit layerParametersChanged();
}

void
SpectrumLayer::setWindowType(WindowType w)
{
    if (m_windowType == w) return;
    m_windowType = w;
    m_newFFTNeeded = true;
    emit layerParametersChanged();
}

void
SpectrumLayer::setShowPeaks(bool show)
{
    if (m_showPeaks == show) return;
    m_showPeaks = show;
    emit layerParametersChanged();
}

void
SpectrumLayer::preferenceChanged(PropertyContainer::PropertyName name)
{
    if (name == "Window Type") {
        setWindowType(Preferences::getInstance()->getWindowType());
        return;
    }
}

bool
SpectrumLayer::getValueExtents(double &, double &, bool &, QString &) const
{
    return false;
}

double
SpectrumLayer::getXForBin(int bin, int totalBins, double w) const
{
    if (!m_sliceableModel) return SliceLayer::getXForBin(bin, totalBins, w);

    sv_samplerate_t sampleRate = m_sliceableModel->getSampleRate();
    double binfreq = (sampleRate * bin) / (totalBins * 2);
    
    return getXForFrequency(binfreq, w);
}

int
SpectrumLayer::getBinForX(double x, int totalBins, double w) const
{
    if (!m_sliceableModel) return SliceLayer::getBinForX(x, totalBins, w);

    sv_samplerate_t sampleRate = m_sliceableModel->getSampleRate();
    double binfreq = getFrequencyForX(x, w);

    return int((binfreq * totalBins * 2) / sampleRate);
}

double
SpectrumLayer::getFrequencyForX(double x, double w) const
{
    double freq = 0;
    if (!m_sliceableModel) return 0;

    sv_samplerate_t sampleRate = m_sliceableModel->getSampleRate();

    double maxfreq = double(sampleRate) / 2;

    switch (m_binScale) {

    case LinearBins:
        freq = ((x * maxfreq) / w);
        break;
        
    case LogBins:
        freq = pow(10.0, (x * log10(maxfreq)) / w);
        break;

    case InvertedLogBins:
        freq = maxfreq - pow(10.0, ((w - x) * log10(maxfreq)) / w);
        break;
    }

    return freq;
}

double
SpectrumLayer::getXForFrequency(double freq, double w) const
{
    double x = 0;
    if (!m_sliceableModel) return x;

    sv_samplerate_t sampleRate = m_sliceableModel->getSampleRate();

    double maxfreq = double(sampleRate) / 2;

    switch (m_binScale) {

    case LinearBins:
        x = (freq * w) / maxfreq;
        break;
        
    case LogBins:
        x = (log10(freq) * w) / log10(maxfreq);
        break;

    case InvertedLogBins:
        if (maxfreq == freq) x = w;
        else x = w - (log10(maxfreq - freq) * w) / log10(maxfreq);
        break;
    }

    return x;
}

bool
SpectrumLayer::getXScaleValue(const LayerGeometryProvider *v, int x, 
                              double &value, QString &unit) const
{
    if (m_xorigins.find(v) == m_xorigins.end()) return false;
    int xorigin = m_xorigins.find(v)->second;
    value = getFrequencyForX(x - xorigin, v->getPaintWidth() - xorigin - 1);
    unit = "Hz";
    return true;
}

bool
SpectrumLayer::getYScaleValue(const LayerGeometryProvider *v, int y,
                              double &value, QString &unit) const
{
    value = getValueForY(y, v);

    if (m_energyScale == dBScale || m_energyScale == MeterScale) {

        if (value > 0.0) {
            value = 10.0 * log10(value);
            if (value < m_threshold) value = m_threshold;
        } else value = m_threshold;

        unit = "dBV";

    } else {
        unit = "V";
    }

    return true;
}

bool
SpectrumLayer::getYScaleDifference(const LayerGeometryProvider *v, int y0, int y1,
                                   double &diff, QString &unit) const
{
    bool rv = SliceLayer::getYScaleDifference(v, y0, y1, diff, unit);
    if (rv && (unit == "dBV")) unit = "dB";
    return rv;
}


bool
SpectrumLayer::getCrosshairExtents(LayerGeometryProvider *v, QPainter &paint,
                                   QPoint cursorPos,
                                   std::vector<QRect> &extents) const
{
    QRect vertical(cursorPos.x(), cursorPos.y(), 1, v->getPaintHeight() - cursorPos.y());
    extents.push_back(vertical);

    QRect horizontal(0, cursorPos.y(), v->getPaintWidth(), 12);
    extents.push_back(horizontal);

    int hoffset = 2;
    if (m_binScale == LogBins) hoffset = 13;

    int sw = getVerticalScaleWidth(v, false, paint);

    QRect value(sw, cursorPos.y() - paint.fontMetrics().ascent() - 2,
                paint.fontMetrics().width("0.0000001 V") + 2,
                paint.fontMetrics().height());
    extents.push_back(value);

    QRect log(sw, cursorPos.y() + 2,
              paint.fontMetrics().width("-80.000 dBV") + 2,
              paint.fontMetrics().height());
    extents.push_back(log);

    QRect freq(cursorPos.x(),
               v->getPaintHeight() - paint.fontMetrics().height() - hoffset,
               paint.fontMetrics().width("123456 Hz") + 2,
               paint.fontMetrics().height());
    extents.push_back(freq);

    int w(paint.fontMetrics().width("C#10+50c") + 2);
    QRect pitch(cursorPos.x() - w,
                v->getPaintHeight() - paint.fontMetrics().height() - hoffset,
                w,
                paint.fontMetrics().height());
    extents.push_back(pitch);

    return true;
}

void
SpectrumLayer::paintCrosshairs(LayerGeometryProvider *v, QPainter &paint,
                               QPoint cursorPos) const
{
    if (!m_sliceableModel) return;

    paint.save();
    QFont fn = paint.font();
    if (fn.pointSize() > 8) {
        fn.setPointSize(fn.pointSize() - 1);
        paint.setFont(fn);
    }

    ColourMapper mapper(m_colourMap, 0, 1);
    paint.setPen(mapper.getContrastingColour());

    int xorigin = m_xorigins[v];
    int w = v->getPaintWidth() - xorigin - 1;
    
    paint.drawLine(xorigin, cursorPos.y(), v->getPaintWidth(), cursorPos.y());
    paint.drawLine(cursorPos.x(), cursorPos.y(), cursorPos.x(), v->getPaintHeight());
    
    double fundamental = getFrequencyForX(cursorPos.x() - xorigin, w);

    int hoffset = 2;
    if (m_binScale == LogBins) hoffset = 13;

    PaintAssistant::drawVisibleText(v, paint,
                       cursorPos.x() + 2,
                       v->getPaintHeight() - 2 - hoffset,
                       QString("%1 Hz").arg(fundamental),
                       PaintAssistant::OutlinedText);

    if (Pitch::isFrequencyInMidiRange(fundamental)) {
        QString pitchLabel = Pitch::getPitchLabelForFrequency(fundamental);
        PaintAssistant::drawVisibleText(v, paint,
                           cursorPos.x() - paint.fontMetrics().width(pitchLabel) - 2,
                           v->getPaintHeight() - 2 - hoffset,
                           pitchLabel,
                           PaintAssistant::OutlinedText);
    }

    double value = getValueForY(cursorPos.y(), v);
    double thresh = m_threshold;
    double db = thresh;
    if (value > 0.0) db = 10.0 * log10(value);
    if (db < thresh) db = thresh;

    PaintAssistant::drawVisibleText(v, paint,
                       xorigin + 2,
                       cursorPos.y() - 2,
                       QString("%1 V").arg(value),
                       PaintAssistant::OutlinedText);

    PaintAssistant::drawVisibleText(v, paint,
                       xorigin + 2,
                       cursorPos.y() + 2 + paint.fontMetrics().ascent(),
                       QString("%1 dBV").arg(db),
                       PaintAssistant::OutlinedText);
    
    int harmonic = 2;

    while (harmonic < 100) {

        int hx = int(lrint(getXForFrequency(fundamental * harmonic, w)));
        hx += xorigin;

        if (hx < xorigin || hx > v->getPaintWidth()) break;
        
        int len = 7;

        if (harmonic % 2 == 0) {
            if (harmonic % 4 == 0) {
                len = 12;
            } else {
                len = 10;
            }
        }

        paint.drawLine(hx,
                       cursorPos.y(),
                       hx,
                       cursorPos.y() + len);

        ++harmonic;
    }

    paint.restore();
}

QString
SpectrumLayer::getFeatureDescription(LayerGeometryProvider *v, QPoint &p) const
{
    if (!m_sliceableModel) return "";

    int minbin = 0, maxbin = 0, range = 0;
    QString genericDesc = SliceLayer::getFeatureDescriptionAux
        (v, p, false, minbin, maxbin, range);

    if (genericDesc == "") return "";

    double minvalue = 0.f;
    if (minbin < int(m_values.size())) minvalue = m_values[minbin];

    double maxvalue = minvalue;
    if (maxbin < int(m_values.size())) maxvalue = m_values[maxbin];
        
    if (minvalue > maxvalue) std::swap(minvalue, maxvalue);
    
    QString binstr;
    QString hzstr;
    int minfreq = int(lrint((minbin * m_sliceableModel->getSampleRate()) /
                            m_windowSize));
    int maxfreq = int(lrint((std::max(maxbin, minbin+1)
                             * m_sliceableModel->getSampleRate()) /
                            m_windowSize));

    if (maxbin != minbin) {
        binstr = tr("%1 - %2").arg(minbin+1).arg(maxbin+1);
    } else {
        binstr = QString("%1").arg(minbin+1);
    }
    if (minfreq != maxfreq) {
        hzstr = tr("%1 - %2 Hz").arg(minfreq).arg(maxfreq);
    } else {
        hzstr = tr("%1 Hz").arg(minfreq);
    }
    
    QString valuestr;
    if (maxvalue != minvalue) {
        valuestr = tr("%1 - %2").arg(minvalue).arg(maxvalue);
    } else {
        valuestr = QString("%1").arg(minvalue);
    }
    
    QString dbstr;
    double mindb = AudioLevel::multiplier_to_dB(minvalue);
    double maxdb = AudioLevel::multiplier_to_dB(maxvalue);
    QString mindbstr;
    QString maxdbstr;
    if (mindb == AudioLevel::DB_FLOOR) {
        mindbstr = tr("-Inf");
    } else {
        mindbstr = QString("%1").arg(lrint(mindb));
    }
    if (maxdb == AudioLevel::DB_FLOOR) {
        maxdbstr = tr("-Inf");
    } else {
        maxdbstr = QString("%1").arg(lrint(maxdb));
    }
    if (lrint(mindb) != lrint(maxdb)) {
        dbstr = tr("%1 - %2").arg(mindbstr).arg(maxdbstr);
    } else {
        dbstr = tr("%1").arg(mindbstr);
    }

    QString description;

    if (range > int(m_sliceableModel->getResolution())) {
        description = tr("%1\nBin:\t%2 (%3)\n%4 value:\t%5\ndB:\t%6")
            .arg(genericDesc)
            .arg(binstr)
            .arg(hzstr)
            .arg(m_samplingMode == NearestSample ? tr("First") :
                 m_samplingMode == SampleMean ? tr("Mean") : tr("Peak"))
            .arg(valuestr)
            .arg(dbstr);
    } else {
        description = tr("%1\nBin:\t%2 (%3)\nValue:\t%4\ndB:\t%5")
            .arg(genericDesc)
            .arg(binstr)
            .arg(hzstr)
            .arg(valuestr)
            .arg(dbstr);
    }
    
    return description;
}

void
SpectrumLayer::paint(LayerGeometryProvider *v, QPainter &paint, QRect rect) const
{
    if (!m_originModel || !m_originModel->isOK() ||
        !m_originModel->isReady()) {
        SVDEBUG << "SpectrumLayer::paint: no origin model, or origin model not OK or not ready" << endl;
        return;
    }

    if (m_newFFTNeeded) {
        SVDEBUG << "SpectrumLayer::paint: new FFT needed, calling setupFFT" << endl;
        const_cast<SpectrumLayer *>(this)->setupFFT(); //ugh
    }

    FFTModel *fft = dynamic_cast<FFTModel *>
        (const_cast<DenseThreeDimensionalModel *>(m_sliceableModel));

    double thresh = (pow(10, -6) / m_gain) * (m_windowSize / 2.0); // -60dB adj

    int xorigin = getVerticalScaleWidth(v, false, paint) + 1;
    int w = v->getPaintWidth() - xorigin - 1;

    int pkh = 0;
//!!!    if (m_binScale == LogBins) {
        pkh = 10;
//!!!    }

    paint.save();

    if (fft && m_showPeaks) {

        // draw peak lines

//        SVDEBUG << "Showing peaks..." << endl;

        int col = int(v->getCentreFrame() / fft->getResolution());

        paint.save();
        paint.setRenderHint(QPainter::Antialiasing, false);
        paint.setPen(QColor(160, 160, 160)); //!!!

        int peakminbin = 0;
        int peakmaxbin = fft->getHeight() - 1;
        double peakmaxfreq = Pitch::getFrequencyForPitch(128);
        peakmaxbin = int(((peakmaxfreq * fft->getHeight() * 2) / fft->getSampleRate()));
        
        FFTModel::PeakSet peaks = fft->getPeakFrequencies
            (FFTModel::MajorPitchAdaptivePeaks, col, peakminbin, peakmaxbin);

        ColourMapper mapper(ColourMapper::BlackOnWhite, 0, 1);

        BiasCurve curve;
        getBiasCurve(curve);
        int cs = int(curve.size());

        std::vector<double> values;
        
        for (int bin = 0; bin < fft->getHeight(); ++bin) {
            double value = m_sliceableModel->getValueAt(col, bin);
            if (bin < cs) value *= curve[bin];
            values.push_back(value);
        }

        for (FFTModel::PeakSet::iterator i = peaks.begin();
             i != peaks.end(); ++i) {

            int bin = i->first;
            
//            cerr << "bin = " << bin << ", thresh = " << thresh << ", value = " << fft->getMagnitudeAt(col, bin) << endl;

            if (!fft->isOverThreshold(col, bin, float(thresh))) continue;
            
            double freq = i->second;
          
            int x = int(lrint(getXForFrequency(freq, w)));

            double norm = 0.f;
            (void)getYForValue(values[bin], v, norm); // don't need return value, need norm

            paint.setPen(mapper.map(norm));
            paint.drawLine(xorigin + x, 0, xorigin + x, v->getPaintHeight() - pkh - 1);
        }

        paint.restore();
    }
    
    SliceLayer::paint(v, paint, rect);

    //!!! All of this stuff relating to depicting frequencies
    //(keyboard, crosshairs etc) should be applicable to any slice
    //layer whose model has a vertical scale unit of Hz.  However, the
    //dense 3d model at the moment doesn't record its vertical scale
    //unit -- we need to fix that and hoist this code as appropriate.
    //Same really goes for any code in SpectrogramLayer that could be
    //relevant to Colour3DPlotLayer with unit Hz, but that's a bigger
    //proposition.

//    if (m_binScale == LogBins) {

//        int pkh = 10;
        int h = v->getPaintHeight();

        // piano keyboard
        //!!! should be in a new paintHorizontalScale()?
        // nice to have a piano keyboard class, of course

	paint.drawLine(xorigin, h - pkh - 1, w + xorigin, h - pkh - 1);

	int px = xorigin, ppx = xorigin;
	paint.setBrush(paint.pen().color());

	for (int i = 0; i < 128; ++i) {

	    double f = Pitch::getFrequencyForPitch(i);
	    int x = int(lrint(getXForFrequency(f, w)));
                           
            x += xorigin;

            if (i == 0) {
                px = ppx = x;
            }
            if (i == 1) {
                ppx = px - (x - px);
            }

            if (x < xorigin) {
                ppx = px;
                px = x;
                continue;
            }
                
            if (x > w) {
                break;
            }

	    int n = (i % 12);

            if (n == 1) {
                // C# -- fill the C from here
                QColor col = Qt::gray;
                if (i == 61) { // filling middle C
                    col = Qt::blue;
                    col = col.light(150);
                }
                if (x - ppx > 2) {
                    paint.fillRect((px + ppx) / 2 + 1,
                                   h - pkh,
                                   x - (px + ppx) / 2 - 1,
                                   pkh,
                                   col);
                }
            }

	    if (n == 1 || n == 3 || n == 6 || n == 8 || n == 10) {
		// black notes
		paint.drawLine(x, h - pkh, x, h);
		int rw = int(lrint(double(x - px) / 4) * 2);
		if (rw < 2) rw = 2;
		paint.drawRect(x - rw/2, h - pkh, rw, pkh/2);
	    } else if (n == 0 || n == 5) {
		// C, F
		if (px < w) {
		    paint.drawLine((x + px) / 2, h - pkh, (x + px) / 2, h);
		}
	    }

            ppx = px;
	    px = x;
	}
//    }

    paint.restore();
}

void
SpectrumLayer::getBiasCurve(BiasCurve &curve) const
{
    curve = m_biasCurve;
}

void
SpectrumLayer::toXml(QTextStream &stream,
                     QString indent, QString extraAttributes) const
{
    QString s = QString("windowSize=\"%1\" "
                        "windowHopLevel=\"%2\" "
                        "showPeaks=\"%3\" ")
        .arg(m_windowSize)
        .arg(m_windowHopLevel)
        .arg(m_showPeaks ? "true" : "false");

    SliceLayer::toXml(stream, indent, extraAttributes + " " + s);
}

void
SpectrumLayer::setProperties(const QXmlAttributes &attributes)
{
    SliceLayer::setProperties(attributes);

    bool ok = false;

    int windowSize = attributes.value("windowSize").toUInt(&ok);
    if (ok) setWindowSize(windowSize);

    int windowHopLevel = attributes.value("windowHopLevel").toUInt(&ok);
    if (ok) setWindowHopLevel(windowHopLevel);

    bool showPeaks = (attributes.value("showPeaks").trimmed() == "true");
    setShowPeaks(showPeaks);
}