annotate layer/SliceLayer.cpp @ 274:b9380f679f70

* Fix centre line position
* Fix failure to update overview when generating peaks from wav file
* Provide y-coordinate scale values and differences for spectrum measurement
  mode, and fix values for waveform (inc dB for both)
* Add Printer colour scheme (may be futile)

/* -*- 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 "SliceLayer.h"

#include "view/View.h"
#include "base/AudioLevel.h"
#include "base/RangeMapper.h"
#include "base/RealTime.h"

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

#include <QPainter>
#include <QPainterPath>

SliceLayer::SliceLayer() :
    m_sliceableModel(0),
    m_colour(Qt::darkBlue),
    m_colourMap(0),
    m_energyScale(dBScale),
    m_samplingMode(SampleMean),
    m_plotStyle(PlotSteps),
    m_binScale(LinearBins),
    m_normalize(false),
    m_gain(1.0),
    m_currentf0(0),
    m_currentf1(0)
{
}

SliceLayer::~SliceLayer()
{

}

void
SliceLayer::setSliceableModel(const Model *model)
{
    const DenseThreeDimensionalModel *sliceable =
        dynamic_cast<const DenseThreeDimensionalModel *>(model);

    if (model && !sliceable) {
        std::cerr << "WARNING: SliceLayer::setSliceableModel(" << model
                  << "): model is not a DenseThreeDimensionalModel" << std::endl;
    }

    if (m_sliceableModel == sliceable) return;

    m_sliceableModel = sliceable;

    connect(m_sliceableModel, SIGNAL(modelChanged()),
            this, SIGNAL(modelChanged()));

    connect(m_sliceableModel, SIGNAL(modelChanged(size_t, size_t)),
	    this, SIGNAL(modelChanged(size_t, size_t)));

    connect(m_sliceableModel, SIGNAL(completionChanged()),
	    this, SIGNAL(modelCompletionChanged()));

    emit modelReplaced();
}

void
SliceLayer::sliceableModelReplaced(const Model *orig, const Model *replacement)
{
    std::cerr << "SliceLayer::sliceableModelReplaced(" << orig << ", " << replacement << ")" << std::endl;

    if (orig == m_sliceableModel) {
        setSliceableModel
            (dynamic_cast<const DenseThreeDimensionalModel *>(replacement));
    }
}

void
SliceLayer::modelAboutToBeDeleted(Model *m)
{
    std::cerr << "SliceLayer::modelAboutToBeDeleted(" << m << ")" << std::endl;

    if (m == m_sliceableModel) {
        setSliceableModel(0);
    }
}

QString
SliceLayer::getFeatureDescription(View *v, QPoint &p) const
{
    int minbin, maxbin, range;
    return getFeatureDescription(v, p, true, minbin, maxbin, range);
}

QString
SliceLayer::getFeatureDescription(View *v, QPoint &p,
                                  bool includeBinDescription,
                                  int &minbin, int &maxbin, int &range) const
{
    minbin = 0;
    maxbin = 0;
    if (!m_sliceableModel) return "";

    int xorigin = m_xorigins[v];
    int w = v->width() - xorigin - 1;
    
    int mh = m_sliceableModel->getHeight();
    minbin = getBinForX(p.x() - xorigin, mh, w);
    maxbin = getBinForX(p.x() - xorigin + 1, mh, w);

    if (minbin >= mh) minbin = mh - 1;
    if (maxbin >= mh) maxbin = mh - 1;
    if (minbin < 0) minbin = 0;
    if (maxbin < 0) maxbin = 0;
    
    int sampleRate = m_sliceableModel->getSampleRate();

    size_t f0 = m_currentf0;
    size_t f1 = m_currentf1;

    RealTime rt0 = RealTime::frame2RealTime(f0, sampleRate);
    RealTime rt1 = RealTime::frame2RealTime(f1, sampleRate);
    
    range = f1 - f0 + 1;

    if (includeBinDescription) {

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

        float maxvalue = minvalue;
        if (maxbin < int(m_values.size())) maxvalue = m_values[maxbin];
        
        if (minvalue > maxvalue) std::swap(minvalue, maxvalue);
        
        QString binstr;
        if (maxbin != minbin) {
            binstr = tr("%1 - %2").arg(minbin+1).arg(maxbin+1);
        } else {
            binstr = QString("%1").arg(minbin+1);
        }

        QString valuestr;
        if (maxvalue != minvalue) {
            valuestr = tr("%1 - %2").arg(minvalue).arg(maxvalue);
        } else {
            valuestr = QString("%1").arg(minvalue);
        }

        QString description = tr("Time:\t%1 - %2\nRange:\t%3 samples\nBin:\t%4\n%5 value:\t%6")
            .arg(QString::fromStdString(rt0.toText(true)))
            .arg(QString::fromStdString(rt1.toText(true)))
            .arg(range)
            .arg(binstr)
            .arg(m_samplingMode == NearestSample ? tr("First") :
                 m_samplingMode == SampleMean ? tr("Mean") : tr("Peak"))
            .arg(valuestr);
        
        return description;
    
    } else {

        QString description = tr("Time:\t%1 - %2\nRange:\t%3 samples")
            .arg(QString::fromStdString(rt0.toText(true)))
            .arg(QString::fromStdString(rt1.toText(true)))
            .arg(range);
        
        return description;
    }
}

float
SliceLayer::getXForBin(int bin, int count, float w) const
{
    float x = 0;

    switch (m_binScale) {

    case LinearBins:
        x = (float(w) * bin) / count;
        break;
        
    case LogBins:
        x = (float(w) * log10f(bin + 1)) / log10f(count + 1);
        break;
        
    case InvertedLogBins:
        x = w - (float(w) * log10f(count - bin - 1)) / log10f(count);
        break;
    }

    return x;
}

int
SliceLayer::getBinForX(float x, int count, float w) const
{
    int bin = 0;

    switch (m_binScale) {

    case LinearBins:
        bin = int((x * count) / w + 0.0001);
        break;
        
    case LogBins:
        bin = int(powf(10.f, (x * log10f(count + 1)) / w) - 1 + 0.0001);
        break;

    case InvertedLogBins:
        bin = count + 1 - int(powf(10.f, (log10f(count) * (w - x)) / float(w)) + 0.0001);
        break;
    }

    return bin;
}

float
SliceLayer::getYForValue(float value, const View *v, float &norm) const
{
    norm = 0.f;

    if (m_yorigins.find(v) == m_yorigins.end()) return 0;

    value *= m_gain;

    int yorigin = m_yorigins[v];
    int h = m_heights[v];
    float thresh = -80.f;

    float y = 0.f;

    if (h <= 0) return y;

    switch (m_energyScale) {

    case dBScale:
    {
        float db = thresh;
        if (value > 0.f) db = 10.f * log10f(value);
        if (db < thresh) db = thresh;
        norm = (db - thresh) / -thresh;
        y = yorigin - (float(h) * norm);
        break;
    }
    
    case MeterScale:
        y = AudioLevel::multiplier_to_preview(value, h);
        norm = float(y) / float(h);
        y = yorigin - y;
        break;
        
    default:
        norm = value;
        y = yorigin - (float(h) * value);
        break;
    }
    
    return y;
}

float
SliceLayer::getValueForY(float y, const View *v) const
{
    float value = 0.f;

    if (m_yorigins.find(v) == m_yorigins.end()) return value;

    int yorigin = m_yorigins[v];
    int h = m_heights[v];
    float thresh = -80.f;

    if (h <= 0) return value;

    y = yorigin - y;

    switch (m_energyScale) {

    case dBScale:
    {
        float db = ((y / h) * -thresh) + thresh;
        value = powf(10.f, db/10.f);
        break;
    }

    case MeterScale:
        value = AudioLevel::preview_to_multiplier(lrintf(y), h);
        break;

    default:
        value = y / h;
    }

    return value / m_gain;
}

void
SliceLayer::paint(View *v, QPainter &paint, QRect rect) const
{
    if (!m_sliceableModel || !m_sliceableModel->isOK() ||
        !m_sliceableModel->isReady()) return;

    paint.save();
    paint.setRenderHint(QPainter::Antialiasing, false);

    if (v->getViewManager() && v->getViewManager()->shouldShowScaleGuides()) {
        if (!m_scalePoints.empty()) {
            paint.setPen(QColor(240, 240, 240)); //!!! and dark background?
            for (size_t i = 0; i < m_scalePoints.size(); ++i) {
                paint.drawLine(0, m_scalePoints[i], rect.width(), m_scalePoints[i]);
            }
        }
    }

    paint.setPen(m_colour);

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

    m_xorigins[v] = xorigin; // for use in getFeatureDescription
    
    int yorigin = v->height() - 20 - paint.fontMetrics().height() - 7;
    int h = yorigin - paint.fontMetrics().height() - 8;

    m_yorigins[v] = yorigin; // for getYForValue etc
    m_heights[v] = h;

    if (h <= 0) return;

    QPainterPath path;

    size_t mh = m_sliceableModel->getHeight();

    int divisor = 0;

    m_values.clear();
    for (size_t bin = 0; bin < mh; ++bin) {
        m_values.push_back(0.f);
    }

    size_t f0 = v->getCentreFrame();
    int f0x = v->getXForFrame(f0);
    f0 = v->getFrameForX(f0x);
    size_t f1 = v->getFrameForX(f0x + 1);
    if (f1 > f0) --f1;

    std::cerr << "centre frame " << v->getCentreFrame() << ", x " << f0x << ", f0 " << f0 << ", f1 " << f1 << std::endl;

    size_t res = m_sliceableModel->getResolution();
    size_t col0 = f0 / res;
    size_t col1 = col0;
    if (m_samplingMode != NearestSample) col1 = f1 / res;
    f0 = col0 * res;
    f1 = (col1 + 1) * res - 1;

    std::cerr << "resolution " << res << ", col0 " << col0 << ", col1 " << col1 << ", f0 " << f0 << ", f1 " << f1 << std::endl;

    m_currentf0 = f0;
    m_currentf1 = f1;

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

    for (size_t col = col0; col <= col1; ++col) {
        for (size_t bin = 0; bin < mh; ++bin) {
            float value = m_sliceableModel->getValueAt(col, bin);
            if (bin < cs) value *= curve[bin];
            if (m_samplingMode == SamplePeak) {
                if (value > m_values[bin]) m_values[bin] = value;
            } else {
                m_values[bin] += value;
            }
        }
        ++divisor;
    }

    float max = 0.f;
    for (size_t bin = 0; bin < mh; ++bin) {
        if (m_samplingMode == SampleMean) m_values[bin] /= divisor;
        if (m_values[bin] > max) max = m_values[bin];
    }
    if (max != 0.f && m_normalize) {
        for (size_t bin = 0; bin < mh; ++bin) {
            m_values[bin] /= max;
        }
    }

    float py = 0;
    float nx = xorigin;

    ColourMapper mapper(m_colourMap, 0, 1);

    for (size_t bin = 0; bin < mh; ++bin) {

        float x = nx;
        nx = xorigin + getXForBin(bin + 1, mh, w);

        float value = m_values[bin];
        float norm = 0.f;
        float y = getYForValue(value, v, norm);

        if (m_plotStyle == PlotLines) {

            if (bin == 0) {
                path.moveTo(x, y);
            } else {
                path.lineTo(x, y);
            }

        } else if (m_plotStyle == PlotSteps) {

            if (bin == 0) {
                path.moveTo(x, y);
            } else {
                path.lineTo(x, y);
            }
            path.lineTo(nx, y);

        } else if (m_plotStyle == PlotBlocks) {

            path.moveTo(x, yorigin);
            path.lineTo(x, y);
            path.lineTo(nx, y);
            path.lineTo(nx, yorigin);
            path.lineTo(x, yorigin);

        } else if (m_plotStyle == PlotFilledBlocks) {

            paint.fillRect(QRectF(x, y, nx - x, yorigin - y), mapper.map(norm));
        }

        py = y;
    }

    if (m_plotStyle != PlotFilledBlocks) {
        paint.drawPath(path);
    }
    paint.restore();
/*
    QPoint discard;

    if (v->getViewManager() && v->getViewManager()->shouldShowFrameCount() &&
        v->shouldIlluminateLocalFeatures(this, discard)) {

        int sampleRate = m_sliceableModel->getSampleRate();

        QString startText = QString("%1 / %2")
            .arg(QString::fromStdString
                 (RealTime::frame2RealTime
                  (f0, sampleRate).toText(true)))
            .arg(f0);

        QString endText = QString(" %1 / %2")
            .arg(QString::fromStdString
                 (RealTime::frame2RealTime
                  (f1, sampleRate).toText(true)))
            .arg(f1);

        QString durationText = QString("(%1 / %2) ")
            .arg(QString::fromStdString
                 (RealTime::frame2RealTime
                  (f1 - f0 + 1, sampleRate).toText(true)))
            .arg(f1 - f0 + 1);

        v->drawVisibleText
            (paint, xorigin + 5,
             paint.fontMetrics().ascent() + 5,
             startText, View::OutlinedText);
        
        v->drawVisibleText
            (paint, xorigin + 5,
             paint.fontMetrics().ascent() + paint.fontMetrics().height() + 10,
             endText, View::OutlinedText);
        
        v->drawVisibleText
            (paint, xorigin + 5,
             paint.fontMetrics().ascent() + 2*paint.fontMetrics().height() + 15,
             durationText, View::OutlinedText);
    }
*/
}

int
SliceLayer::getVerticalScaleWidth(View *, QPainter &paint) const
{
    if (m_energyScale == LinearScale) {
	return std::max(paint.fontMetrics().width("0.0") + 13,
                        paint.fontMetrics().width("x10-10"));
    } else {
	return std::max(paint.fontMetrics().width(tr("0dB")),
			paint.fontMetrics().width(tr("-Inf"))) + 13;
    }
}

void
SliceLayer::paintVerticalScale(View *v, QPainter &paint, QRect rect) const
{
    float thresh = 0;
    if (m_energyScale != LinearScale) {
        thresh = AudioLevel::dB_to_multiplier(-80); //!!! thresh
    }
    
//    int h = (rect.height() * 3) / 4;
//    int y = (rect.height() / 2) - (h / 2);
    
    int yorigin = v->height() - 20 - paint.fontMetrics().height() - 6;
    int h = yorigin - paint.fontMetrics().height() - 8;
    if (h < 0) return;

    QRect actual(rect.x(), rect.y() + yorigin - h, rect.width(), h);

    int mult = 1;

    PaintAssistant::paintVerticalLevelScale
        (paint, actual, thresh, 1.0 / m_gain,
         PaintAssistant::Scale(m_energyScale),
         mult,
         const_cast<std::vector<int> *>(&m_scalePoints));

    if (mult != 1 && mult != 0) {
        int log = lrintf(log10f(mult));
        QString a = tr("x10");
        QString b = QString("%1").arg(-log);
        paint.drawText(3, 8 + paint.fontMetrics().ascent(), a);
        paint.drawText(3 + paint.fontMetrics().width(a),
                       3 + paint.fontMetrics().ascent(), b);
    }
}

Layer::PropertyList
SliceLayer::getProperties() const
{
    PropertyList list;
    list.push_back("Colour");
    list.push_back("Plot Type");
//    list.push_back("Sampling Mode");
    list.push_back("Scale");
    list.push_back("Normalize");
    list.push_back("Gain");
    list.push_back("Bin Scale");

    return list;
}

QString
SliceLayer::getPropertyLabel(const PropertyName &name) const
{
    if (name == "Colour") return tr("Colour");
    if (name == "Plot Type") return tr("Plot Type");
    if (name == "Energy Scale") return tr("Scale");
    if (name == "Normalize") return tr("Normalize");
    if (name == "Gain") return tr("Gain");
    if (name == "Sampling Mode") return tr("Sampling Mode");
    if (name == "Bin Scale") return tr("Plot X Scale");
    return "";
}

Layer::PropertyType
SliceLayer::getPropertyType(const PropertyName &name) const
{
    if (name == "Gain") return RangeProperty;
    if (name == "Normalize") return ToggleProperty;
    return ValueProperty;
}

QString
SliceLayer::getPropertyGroupName(const PropertyName &name) const
{
    if (name == "Scale" ||
        name == "Normalize" ||
        name == "Sampling Mode" ||
        name == "Gain") return tr("Scale");
    if (name == "Plot Type" ||
        name == "Bin Scale") return tr("Plot Type");
    return QString();
}

int
SliceLayer::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 == "Gain") {

	*min = -50;
	*max = 50;
        *deflt = 0;

        std::cerr << "gain is " << m_gain << ", mode is " << m_samplingMode << std::endl;

	val = lrint(log10(m_gain) * 20.0);
	if (val < *min) val = *min;
	if (val > *max) val = *max;

    } else if (name == "Normalize") {
	
	val = (m_normalize ? 1 : 0);
        *deflt = 0;

    } else if (name == "Colour") {

        if (m_plotStyle == PlotFilledBlocks) {
            
            *min = 0;
            *max = ColourMapper::getColourMapCount() - 1;
            *deflt = 0;

            val = m_colourMap;

        } else {

            *min = 0;
            *max = 5;
            *deflt = 0;

            if (m_colour == Qt::black) val = 0;
            else if (m_colour == Qt::darkRed) val = 1;
            else if (m_colour == Qt::darkBlue) val = 2;
            else if (m_colour == Qt::darkGreen) val = 3;
            else if (m_colour == QColor(200, 50, 255)) val = 4;
            else if (m_colour == QColor(255, 150, 50)) val = 5;
        }

    } else if (name == "Scale") {

	*min = 0;
	*max = 2;
        *deflt = (int)dBScale;

	val = (int)m_energyScale;

    } else if (name == "Sampling Mode") {

	*min = 0;
	*max = 2;
        *deflt = (int)SampleMean;
        
	val = (int)m_samplingMode;

    } else if (name == "Plot Type") {
        
        *min = 0;
        *max = 3;
        *deflt = (int)PlotSteps;

        val = (int)m_plotStyle;

    } else if (name == "Bin Scale") {
        
        *min = 0;
        *max = 2;
        *deflt = (int)LinearBins;
//        *max = 1; // I don't think we really do want to offer inverted log

        val = (int)m_binScale;

    } else {
	val = Layer::getPropertyRangeAndValue(name, min, max, deflt);
    }

    return val;
}

QString
SliceLayer::getPropertyValueLabel(const PropertyName &name,
				    int value) const
{
    if (name == "Colour") {
        if (m_plotStyle == PlotFilledBlocks) {
            return ColourMapper::getColourMapName(value);
        } else {
            switch (value) {
            default:
            case 0: return tr("Black");
            case 1: return tr("Red");
            case 2: return tr("Blue");
            case 3: return tr("Green");
            case 4: return tr("Purple");
            case 5: return tr("Orange");
            }
	}
    }
    if (name == "Scale") {
	switch (value) {
	default:
	case 0: return tr("Linear");
	case 1: return tr("Meter");
	case 2: return tr("dB");
	}
    }
    if (name == "Sampling Mode") {
	switch (value) {
	default:
	case 0: return tr("Any");
	case 1: return tr("Mean");
	case 2: return tr("Peak");
	}
    }
    if (name == "Plot Type") {
	switch (value) {
	default:
	case 0: return tr("Lines");
	case 1: return tr("Steps");
	case 2: return tr("Blocks");
	case 3: return tr("Colours");
	}
    }
    if (name == "Bin Scale") {
	switch (value) {
	default:
	case 0: return tr("Linear Bins");
	case 1: return tr("Log Bins");
	case 2: return tr("Rev Log Bins");
	}
    }
    return tr("<unknown>");
}

RangeMapper *
SliceLayer::getNewPropertyRangeMapper(const PropertyName &name) const
{
    if (name == "Gain") {
        return new LinearRangeMapper(-50, 50, -25, 25, tr("dB"));
    }
    return 0;
}

void
SliceLayer::setProperty(const PropertyName &name, int value)
{
    if (name == "Gain") {
	setGain(pow(10, float(value)/20.0));
    } else if (name == "Colour") {
        if (m_plotStyle == PlotFilledBlocks) {
            setFillColourMap(value);
        } else {
            switch (value) {
            default:
            case 0: setBaseColour(Qt::black); break;
            case 1: setBaseColour(Qt::darkRed); break;
            case 2: setBaseColour(Qt::darkBlue); break;
            case 3: setBaseColour(Qt::darkGreen); break;
            case 4: setBaseColour(QColor(200, 50, 255)); break;
            case 5: setBaseColour(QColor(255, 150, 50)); break;
            }
	}
    } else if (name == "Scale") {
	switch (value) {
	default:
	case 0: setEnergyScale(LinearScale); break;
	case 1: setEnergyScale(MeterScale); break;
	case 2: setEnergyScale(dBScale); break;
	}
    } else if (name == "Plot Type") {
	setPlotStyle(PlotStyle(value));
    } else if (name == "Sampling Mode") {
	switch (value) {
	default:
	case 0: setSamplingMode(NearestSample); break;
	case 1: setSamplingMode(SampleMean); break;
	case 2: setSamplingMode(SamplePeak); break;
	}
    } else if (name == "Bin Scale") {
	switch (value) {
	default:
	case 0: setBinScale(LinearBins); break;
	case 1: setBinScale(LogBins); break;
	case 2: setBinScale(InvertedLogBins); break;
	}
    } else if (name == "Normalize") {
	setNormalize(value ? true : false);
    }
}

void
SliceLayer::setBaseColour(QColor colour)
{
    if (m_colour == colour) return;
    m_colour = colour;
    emit layerParametersChanged();
}

void
SliceLayer::setFillColourMap(int map)
{
    if (m_colourMap == map) return;
    m_colourMap = map;
    emit layerParametersChanged();
}

void
SliceLayer::setEnergyScale(EnergyScale scale)
{
    if (m_energyScale == scale) return;
    m_energyScale = scale;
    emit layerParametersChanged();
}

void
SliceLayer::setSamplingMode(SamplingMode mode)
{
    if (m_samplingMode == mode) return;
    m_samplingMode = mode;
    emit layerParametersChanged();
}

void
SliceLayer::setPlotStyle(PlotStyle style)
{
    if (m_plotStyle == style) return;
    bool colourTypeChanged = (style == PlotFilledBlocks ||
                              m_plotStyle == PlotFilledBlocks);
    m_plotStyle = style;
    if (colourTypeChanged) {
        emit layerParameterRangesChanged();
    }
    emit layerParametersChanged();
}

void
SliceLayer::setBinScale(BinScale scale)
{
    if (m_binScale == scale) return;
    m_binScale = scale;
    emit layerParametersChanged();
}

void
SliceLayer::setNormalize(bool n)
{
    if (m_normalize == n) return;
    m_normalize = n;
    emit layerParametersChanged();
}

void
SliceLayer::setGain(float gain)
{
    if (m_gain == gain) return;
    m_gain = gain;
    emit layerParametersChanged();
}

QString
SliceLayer::toXmlString(QString indent, QString extraAttributes) const
{
    QString s;
    
    s += QString("colour=\"%1\" "
                 "colourScheme=\"%2\" "
		 "energyScale=\"%3\" "
                 "samplingMode=\"%4\" "
                 "gain=\"%5\" "
                 "normalize=\"%6\"")
	.arg(encodeColour(m_colour))
        .arg(m_colourMap)
	.arg(m_energyScale)
        .arg(m_samplingMode)
        .arg(m_gain)
        .arg(m_normalize ? "true" : "false");

    return Layer::toXmlString(indent, extraAttributes + " " + s);
}

void
SliceLayer::setProperties(const QXmlAttributes &attributes)
{
    bool ok = false;

    QString colourSpec = attributes.value("colour");
    if (colourSpec != "") {
	QColor colour(colourSpec);
	if (colour.isValid()) {
	    setBaseColour(QColor(colourSpec));
	}
    }

    EnergyScale scale = (EnergyScale)
	attributes.value("energyScale").toInt(&ok);
    if (ok) setEnergyScale(scale);

    SamplingMode mode = (SamplingMode)
	attributes.value("samplingMode").toInt(&ok);
    if (ok) setSamplingMode(mode);

    int colourMap = attributes.value("colourScheme").toInt(&ok);
    if (ok) setFillColourMap(colourMap);

    float gain = attributes.value("gain").toFloat(&ok);
    if (ok) setGain(gain);

    bool normalize = (attributes.value("normalize").trimmed() == "true");
    setNormalize(normalize);
}

bool
SliceLayer::getValueExtents(float &, float &, bool &, QString &) const
{
    return false;
}