view layer/SliceLayer.cpp @ 789:9fd1bdf214dd tonioni

Play pointer: when user drags pane during playback such that the pointer is no longer visible, accept that and stop trying to track it until pointer naturally comes back within visible area
author Chris Cannam
date Thu, 12 Jun 2014 12:48:11 +0100
parents 1a0dfcbffaf1
children 1d526ba11a24
line wrap: on
line source
/* -*- 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 "ColourDatabase.h"

#include "PaintAssistant.h"

#include <QPainter>
#include <QPainterPath>
#include <QTextStream>


SliceLayer::SliceLayer() :
    m_sliceableModel(0),
    m_colourMap(0),
    m_energyScale(dBScale),
    m_samplingMode(SampleMean),
    m_plotStyle(PlotSteps),
    m_binScale(LinearBins),
    m_normalize(false),
    m_threshold(0.0),
    m_initialThreshold(0.0),
    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) {
        cerr << "WARNING: SliceLayer::setSliceableModel(" << model
                  << "): model is not a DenseThreeDimensionalModel" << endl;
    }

    if (m_sliceableModel == sliceable) return;

    m_sliceableModel = sliceable;

    connectSignals(m_sliceableModel);

    emit modelReplaced();
}

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

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

void
SliceLayer::modelAboutToBeDeleted(Model *m)
{
    SVDEBUG << "SliceLayer::modelAboutToBeDeleted(" << m << ")" << 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;

    QString rtrangestr = QString("%1 s").arg((rt1 - rt0).toText().c_str());

    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 (%4)\nBin:\t%5\n%6 value:\t%7")
            .arg(QString::fromStdString(rt0.toText(true)))
            .arg(QString::fromStdString(rt1.toText(true)))
            .arg(range)
            .arg(rtrangestr)
            .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 (%4)")
            .arg(QString::fromStdString(rt0.toText(true)))
            .arg(QString::fromStdString(rt1.toText(true)))
            .arg(range)
            .arg(rtrangestr);
        
        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 = getThresholdDb();

    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(fabsf(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;
        
    case AbsoluteScale:
        value = fabsf(value);
        // and fall through
        
    default:
        norm = (value - m_threshold);
        if (norm < 0) norm = 0;
        y = yorigin - (float(h) * norm);
        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 = getThresholdDb();

    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 + m_threshold;
    }

    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);
    paint.setBrush(Qt::NoBrush);

    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(getBaseQColor());

    int xorigin = getVerticalScaleWidth(v, true, 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;

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

//    cerr << "resolution " << res << ", col0 " << col0 << ", col1 " << col1 << ", f0 " << f0 << ", f1 " << f1 << 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 *, bool, QPainter &paint) const
{
    if (m_energyScale == LinearScale || m_energyScale == AbsoluteScale) {
	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, bool, QPainter &paint, QRect rect) const
{
    float thresh = m_threshold;
    if (m_energyScale != LinearScale && m_energyScale != AbsoluteScale) {
        thresh = AudioLevel::dB_to_multiplier(getThresholdDb());
    }
    
//    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 = SingleColourLayer::getProperties();
    list.push_back("Bin Scale");
    list.push_back("Plot Type");
    list.push_back("Scale");
    list.push_back("Normalize");
    list.push_back("Threshold");
    list.push_back("Gain");

    return list;
}

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

QString
SliceLayer::getPropertyIconName(const PropertyName &name) const
{
    if (name == "Normalize") return "normalise";
    return "";
}

Layer::PropertyType
SliceLayer::getPropertyType(const PropertyName &name) const
{
    if (name == "Gain") return RangeProperty;
    if (name == "Normalize") return ToggleProperty;
    if (name == "Threshold") return RangeProperty;
    if (name == "Plot Type") return ValueProperty;
    if (name == "Scale") return ValueProperty;
    if (name == "Sampling Mode") return ValueProperty;
    if (name == "Bin Scale") return ValueProperty;
    if (name == "Colour" && m_plotStyle == PlotFilledBlocks) return ValueProperty;
    return SingleColourLayer::getPropertyType(name);
}

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

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;

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

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

    } else if (name == "Threshold") {
        
	*min = -80;
	*max = 0;

        *deflt = lrintf(AudioLevel::multiplier_to_dB(m_initialThreshold));
	if (*deflt < *min) *deflt = *min;
	if (*deflt > *max) *deflt = *max;

	val = lrintf(AudioLevel::multiplier_to_dB(m_threshold));
	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" && m_plotStyle == PlotFilledBlocks) {
            
        *min = 0;
        *max = ColourMapper::getColourMapCount() - 1;
        *deflt = 0;
        
        val = m_colourMap;

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

	*min = 0;
	*max = 3;
        *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 = SingleColourLayer::getPropertyRangeAndValue(name, min, max, deflt);
    }

    return val;
}

QString
SliceLayer::getPropertyValueLabel(const PropertyName &name,
				    int value) const
{
    if (name == "Colour" && m_plotStyle == PlotFilledBlocks) {
        return ColourMapper::getColourMapName(value);
    }
    if (name == "Scale") {
	switch (value) {
	default:
	case 0: return tr("Linear");
	case 1: return tr("Meter");
	case 2: return tr("Log");
	case 3: return tr("Absolute");
	}
    }
    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");
	case 1: return tr("Log");
	case 2: return tr("Rev Log");
	}
    }
    return SingleColourLayer::getPropertyValueLabel(name, value);
}

RangeMapper *
SliceLayer::getNewPropertyRangeMapper(const PropertyName &name) const
{
    if (name == "Gain") {
        return new LinearRangeMapper(-50, 50, -25, 25, tr("dB"));
    }
    if (name == "Threshold") {
        return new LinearRangeMapper(-80, 0, -80, 0, tr("dB"));
    }
    return SingleColourLayer::getNewPropertyRangeMapper(name);
}

void
SliceLayer::setProperty(const PropertyName &name, int value)
{
    if (name == "Gain") {
	setGain(pow(10, float(value)/20.0));
    } else if (name == "Threshold") {
	if (value == -80) setThreshold(0.0);
	else setThreshold(AudioLevel::dB_to_multiplier(value));
    } else if (name == "Colour" && m_plotStyle == PlotFilledBlocks) {
        setFillColourMap(value);
    } else if (name == "Scale") {
	switch (value) {
	default:
	case 0: setEnergyScale(LinearScale); break;
	case 1: setEnergyScale(MeterScale); break;
	case 2: setEnergyScale(dBScale); break;
	case 3: setEnergyScale(AbsoluteScale); 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);
    } else {
        SingleColourLayer::setProperty(name, value);
    }
}

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::setThreshold(float thresh)
{
    if (m_threshold == thresh) return;
    m_threshold = thresh;
    emit layerParametersChanged();
}

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

float
SliceLayer::getThresholdDb() const
{
    if (m_threshold == 0.0) return -80.f;
    float db = AudioLevel::multiplier_to_dB(m_threshold);
    return db;
}

int
SliceLayer::getDefaultColourHint(bool darkbg, bool &impose)
{
    impose = false;
    return ColourDatabase::getInstance()->getColourIndex
        (QString(darkbg ? "Bright Blue" : "Blue"));
}

void
SliceLayer::toXml(QTextStream &stream,
                  QString indent, QString extraAttributes) const
{
    QString s;
    
    s += QString("colourScheme=\"%1\" "
		 "energyScale=\"%2\" "
                 "samplingMode=\"%3\" "
                 "plotStyle=\"%4\" "
                 "binScale=\"%5\" "
                 "gain=\"%6\" "
                 "threshold=\"%7\" "
                 "normalize=\"%8\"")
        .arg(m_colourMap)
	.arg(m_energyScale)
        .arg(m_samplingMode)
        .arg(m_plotStyle)
        .arg(m_binScale)
        .arg(m_gain)
        .arg(m_threshold)
        .arg(m_normalize ? "true" : "false");

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

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

    SingleColourLayer::setProperties(attributes);

    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);

    PlotStyle s = (PlotStyle)
	attributes.value("plotStyle").toInt(&ok);
    if (ok) setPlotStyle(s);

    BinScale b = (BinScale)
	attributes.value("binScale").toInt(&ok);
    if (ok) setBinScale(b);

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

    float threshold = attributes.value("threshold").toFloat(&ok);
    if (ok) setThreshold(threshold);

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

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