view layer/SpectrogramLayer.cpp @ 1024:3bce4c45b681 spectrogram-minor-refactor

Rearrange cache update calculations so as to use the actual painted width returned by paint functions (though they only ever return the same width as requested, at this point)
author Chris Cannam
date Mon, 25 Jan 2016 15:52:26 +0000
parents 74755fa6ea9e
children c02de0e34233
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 2006-2009 Chris Cannam and 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 "SpectrogramLayer.h"

#include "view/View.h"
#include "base/Profiler.h"
#include "base/AudioLevel.h"
#include "base/Window.h"
#include "base/Pitch.h"
#include "base/Preferences.h"
#include "base/RangeMapper.h"
#include "base/LogRange.h"
#include "widgets/CommandHistory.h"
#include "ColourMapper.h"
#include "ImageRegionFinder.h"
#include "data/model/Dense3DModelPeakCache.h"
#include "PianoScale.h"

#include <QPainter>
#include <QImage>
#include <QPixmap>
#include <QRect>
#include <QTimer>
#include <QApplication>
#include <QMessageBox>
#include <QMouseEvent>
#include <QTextStream>
#include <QSettings>

#include <iostream>

#include <cassert>
#include <cmath>

#ifndef __GNUC__
#include <alloca.h>
#endif

//#define DEBUG_SPECTROGRAM_REPAINT 1

using std::vector;

SpectrogramLayer::SpectrogramLayer(Configuration config) :
    m_model(0),
    m_channel(0),
    m_windowSize(1024),
    m_windowType(HanningWindow),
    m_windowHopLevel(2),
    m_zeroPadLevel(0),
    m_fftSize(1024),
    m_gain(1.0),
    m_initialGain(1.0),
    m_threshold(0.0),
    m_initialThreshold(0.0),
    m_colourRotation(0),
    m_initialRotation(0),
    m_minFrequency(10),
    m_maxFrequency(8000),
    m_initialMaxFrequency(8000),
    m_colourScale(dBColourScale),
    m_colourMap(0),
    m_frequencyScale(LinearFrequencyScale),
    m_binDisplay(AllBins),
    m_normalization(NoNormalization),
    m_lastEmittedZoomStep(-1),
    m_synchronous(false),
    m_haveDetailedScale(false),
    m_lastPaintBlockWidth(0),
    m_exiting(false),
    m_sliceableModel(0)
{
    QString colourConfigName = "spectrogram-colour";
    int colourConfigDefault = int(ColourMapper::Green);
    
    if (config == FullRangeDb) {
        m_initialMaxFrequency = 0;
        setMaxFrequency(0);
    } else if (config == MelodicRange) {
	setWindowSize(8192);
	setWindowHopLevel(4);
        m_initialMaxFrequency = 1500;
	setMaxFrequency(1500);
        setMinFrequency(40);
	setColourScale(LinearColourScale);
        setColourMap(ColourMapper::Sunset);
        setFrequencyScale(LogFrequencyScale);
        colourConfigName = "spectrogram-melodic-colour";
        colourConfigDefault = int(ColourMapper::Sunset);
//        setGain(20);
    } else if (config == MelodicPeaks) {
	setWindowSize(4096);
	setWindowHopLevel(5);
        m_initialMaxFrequency = 2000;
	setMaxFrequency(2000);
	setMinFrequency(40);
	setFrequencyScale(LogFrequencyScale);
	setColourScale(LinearColourScale);
	setBinDisplay(PeakFrequencies);
        setNormalization(NormalizeColumns);
        colourConfigName = "spectrogram-melodic-colour";
        colourConfigDefault = int(ColourMapper::Sunset);
    }

    QSettings settings;
    settings.beginGroup("Preferences");
    setColourMap(settings.value(colourConfigName, colourConfigDefault).toInt());
    settings.endGroup();
    
    Preferences *prefs = Preferences::getInstance();
    connect(prefs, SIGNAL(propertyChanged(PropertyContainer::PropertyName)),
            this, SLOT(preferenceChanged(PropertyContainer::PropertyName)));
    setWindowType(prefs->getWindowType());

    initialisePalette();
}

SpectrogramLayer::~SpectrogramLayer()
{
    invalidateFFTModels();
}

void
SpectrogramLayer::setModel(const DenseTimeValueModel *model)
{
//    cerr << "SpectrogramLayer(" << this << "): setModel(" << model << ")" << endl;

    if (model == m_model) return;

    m_model = model;
    invalidateFFTModels();

    if (!m_model || !m_model->isOK()) return;

    connectSignals(m_model);

    connect(m_model, SIGNAL(modelChanged()), this, SLOT(cacheInvalid()));
    connect(m_model, SIGNAL(modelChangedWithin(sv_frame_t, sv_frame_t)),
	    this, SLOT(cacheInvalid(sv_frame_t, sv_frame_t)));

    emit modelReplaced();
}

Layer::PropertyList
SpectrogramLayer::getProperties() const
{
    PropertyList list;
    list.push_back("Colour");
    list.push_back("Colour Scale");
    list.push_back("Window Size");
    list.push_back("Window Increment");
    list.push_back("Normalization");
    list.push_back("Bin Display");
    list.push_back("Threshold");
    list.push_back("Gain");
    list.push_back("Colour Rotation");
//    list.push_back("Min Frequency");
//    list.push_back("Max Frequency");
    list.push_back("Frequency Scale");
////    list.push_back("Zero Padding");
    return list;
}

QString
SpectrogramLayer::getPropertyLabel(const PropertyName &name) const
{
    if (name == "Colour") return tr("Colour");
    if (name == "Colour Scale") return tr("Colour Scale");
    if (name == "Window Size") return tr("Window Size");
    if (name == "Window Increment") return tr("Window Overlap");
    if (name == "Normalization") return tr("Normalization");
    if (name == "Bin Display") return tr("Bin Display");
    if (name == "Threshold") return tr("Threshold");
    if (name == "Gain") return tr("Gain");
    if (name == "Colour Rotation") return tr("Colour Rotation");
    if (name == "Min Frequency") return tr("Min Frequency");
    if (name == "Max Frequency") return tr("Max Frequency");
    if (name == "Frequency Scale") return tr("Frequency Scale");
    if (name == "Zero Padding") return tr("Smoothing");
    return "";
}

QString
SpectrogramLayer::getPropertyIconName(const PropertyName &) const
{
    return "";
}

Layer::PropertyType
SpectrogramLayer::getPropertyType(const PropertyName &name) const
{
    if (name == "Gain") return RangeProperty;
    if (name == "Colour Rotation") return RangeProperty;
    if (name == "Threshold") return RangeProperty;
    if (name == "Zero Padding") return ToggleProperty;
    return ValueProperty;
}

QString
SpectrogramLayer::getPropertyGroupName(const PropertyName &name) const
{
    if (name == "Bin Display" ||
        name == "Frequency Scale") return tr("Bins");
    if (name == "Window Size" ||
	name == "Window Increment" ||
        name == "Zero Padding") return tr("Window");
    if (name == "Colour" ||
	name == "Threshold" ||
	name == "Colour Rotation") return tr("Colour");
    if (name == "Normalization" ||
        name == "Gain" ||
	name == "Colour Scale") return tr("Scale");
    return QString();
}

int
SpectrogramLayer::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 = int(lrint(log10(m_initialGain) * 20.0));
	if (*deflt < *min) *deflt = *min;
	if (*deflt > *max) *deflt = *max;

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

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

	*min = -50;
	*max = 0;

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

	val = int(lrint(AudioLevel::multiplier_to_dB(m_threshold)));
	if (val < *min) val = *min;
	if (val > *max) val = *max;

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

	*min = 0;
	*max = 256;
        *deflt = m_initialRotation;

	val = m_colourRotation;

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

	*min = 0;
	*max = 4;
        *deflt = int(dBColourScale);

	val = (int)m_colourScale;

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

	*min = 0;
	*max = ColourMapper::getColourMapCount() - 1;
        *deflt = 0;

	val = m_colourMap;

    } else if (name == "Window Size") {

	*min = 0;
	*max = 10;
        *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 == "Zero Padding") {
	
	*min = 0;
	*max = 1;
        *deflt = 0;
	
        val = m_zeroPadLevel > 0 ? 1 : 0;
    
    } else if (name == "Min Frequency") {

	*min = 0;
	*max = 9;
        *deflt = 1;

	switch (m_minFrequency) {
	case 0: default: val = 0; break;
	case 10: val = 1; break;
	case 20: val = 2; break;
	case 40: val = 3; break;
	case 100: val = 4; break;
	case 250: val = 5; break;
	case 500: val = 6; break;
	case 1000: val = 7; break;
	case 4000: val = 8; break;
	case 10000: val = 9; break;
	}
    
    } else if (name == "Max Frequency") {

	*min = 0;
	*max = 9;
        *deflt = 6;

	switch (m_maxFrequency) {
	case 500: val = 0; break;
	case 1000: val = 1; break;
	case 1500: val = 2; break;
	case 2000: val = 3; break;
	case 4000: val = 4; break;
	case 6000: val = 5; break;
	case 8000: val = 6; break;
	case 12000: val = 7; break;
	case 16000: val = 8; break;
	default: val = 9; break;
	}

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

	*min = 0;
	*max = 1;
        *deflt = int(LinearFrequencyScale);
	val = (int)m_frequencyScale;

    } else if (name == "Bin Display") {

	*min = 0;
	*max = 2;
        *deflt = int(AllBins);
	val = (int)m_binDisplay;

    } else if (name == "Normalization") {
	
        *min = 0;
        *max = 3;
        *deflt = int(NoNormalization);
        val = (int)m_normalization;

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

    return val;
}

QString
SpectrogramLayer::getPropertyValueLabel(const PropertyName &name,
					int value) const
{
    if (name == "Colour") {
        return ColourMapper::getColourMapName(value);
    }
    if (name == "Colour Scale") {
	switch (value) {
	default:
	case 0: return tr("Linear");
	case 1: return tr("Meter");
	case 2: return tr("dBV^2");
	case 3: return tr("dBV");
	case 4: return tr("Phase");
	}
    }
    if (name == "Normalization") {
        return ""; // icon only
    }
    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 %");
	}
    }
    if (name == "Zero Padding") {
        if (value == 0) return tr("None");
        return QString("%1x").arg(value + 1);
    }
    if (name == "Min Frequency") {
	switch (value) {
	default:
	case 0: return tr("No min");
	case 1: return tr("10 Hz");
	case 2: return tr("20 Hz");
	case 3: return tr("40 Hz");
	case 4: return tr("100 Hz");
	case 5: return tr("250 Hz");
	case 6: return tr("500 Hz");
	case 7: return tr("1 KHz");
	case 8: return tr("4 KHz");
	case 9: return tr("10 KHz");
	}
    }
    if (name == "Max Frequency") {
	switch (value) {
	default:
	case 0: return tr("500 Hz");
	case 1: return tr("1 KHz");
	case 2: return tr("1.5 KHz");
	case 3: return tr("2 KHz");
	case 4: return tr("4 KHz");
	case 5: return tr("6 KHz");
	case 6: return tr("8 KHz");
	case 7: return tr("12 KHz");
	case 8: return tr("16 KHz");
	case 9: return tr("No max");
	}
    }
    if (name == "Frequency Scale") {
	switch (value) {
	default:
	case 0: return tr("Linear");
	case 1: return tr("Log");
	}
    }
    if (name == "Bin Display") {
	switch (value) {
	default:
	case 0: return tr("All Bins");
	case 1: return tr("Peak Bins");
	case 2: return tr("Frequencies");
	}
    }
    return tr("<unknown>");
}

QString
SpectrogramLayer::getPropertyValueIconName(const PropertyName &name,
                                           int value) const
{
    if (name == "Normalization") {
        switch(value) {
        default:
        case 0: return "normalise-none";
        case 1: return "normalise-columns";
        case 2: return "normalise";
        case 3: return "normalise-hybrid";
        }
    }
    return "";
}

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

void
SpectrogramLayer::setProperty(const PropertyName &name, int value)
{
    if (name == "Gain") {
	setGain(float(pow(10, float(value)/20.0)));
    } else if (name == "Threshold") {
	if (value == -50) setThreshold(0.0);
	else setThreshold(float(AudioLevel::dB_to_multiplier(value)));
    } else if (name == "Colour Rotation") {
	setColourRotation(value);
    } else if (name == "Colour") {
        setColourMap(value);
    } else if (name == "Window Size") {
	setWindowSize(32 << value);
    } else if (name == "Window Increment") {
        setWindowHopLevel(value);
    } else if (name == "Zero Padding") {
        setZeroPadLevel(value > 0.1 ? 3 : 0);
    } else if (name == "Min Frequency") {
	switch (value) {
	default:
	case 0: setMinFrequency(0); break;
	case 1: setMinFrequency(10); break;
	case 2: setMinFrequency(20); break;
	case 3: setMinFrequency(40); break;
	case 4: setMinFrequency(100); break;
	case 5: setMinFrequency(250); break;
	case 6: setMinFrequency(500); break;
	case 7: setMinFrequency(1000); break;
	case 8: setMinFrequency(4000); break;
	case 9: setMinFrequency(10000); break;
	}
        int vs = getCurrentVerticalZoomStep();
        if (vs != m_lastEmittedZoomStep) {
            emit verticalZoomChanged();
            m_lastEmittedZoomStep = vs;
        }
    } else if (name == "Max Frequency") {
	switch (value) {
	case 0: setMaxFrequency(500); break;
	case 1: setMaxFrequency(1000); break;
	case 2: setMaxFrequency(1500); break;
	case 3: setMaxFrequency(2000); break;
	case 4: setMaxFrequency(4000); break;
	case 5: setMaxFrequency(6000); break;
	case 6: setMaxFrequency(8000); break;
	case 7: setMaxFrequency(12000); break;
	case 8: setMaxFrequency(16000); break;
	default:
	case 9: setMaxFrequency(0); break;
	}
        int vs = getCurrentVerticalZoomStep();
        if (vs != m_lastEmittedZoomStep) {
            emit verticalZoomChanged();
            m_lastEmittedZoomStep = vs;
        }
    } else if (name == "Colour Scale") {
	switch (value) {
	default:
	case 0: setColourScale(LinearColourScale); break;
	case 1: setColourScale(MeterColourScale); break;
	case 2: setColourScale(dBSquaredColourScale); break;
	case 3: setColourScale(dBColourScale); break;
	case 4: setColourScale(PhaseColourScale); break;
	}
    } else if (name == "Frequency Scale") {
	switch (value) {
	default:
	case 0: setFrequencyScale(LinearFrequencyScale); break;
	case 1: setFrequencyScale(LogFrequencyScale); break;
	}
    } else if (name == "Bin Display") {
	switch (value) {
	default:
	case 0: setBinDisplay(AllBins); break;
	case 1: setBinDisplay(PeakBins); break;
	case 2: setBinDisplay(PeakFrequencies); break;
	}
    } else if (name == "Normalization") {
        switch (value) {
        default:
        case 0: setNormalization(NoNormalization); break;
        case 1: setNormalization(NormalizeColumns); break;
        case 2: setNormalization(NormalizeVisibleArea); break;
        case 3: setNormalization(NormalizeHybrid); break;
        }
    }
}

void
SpectrogramLayer::invalidateImageCaches()
{
    for (ViewImageCache::iterator i = m_imageCaches.begin();
         i != m_imageCaches.end(); ++i) {
        i->second.validArea = QRect();
    }
}

void
SpectrogramLayer::invalidateImageCaches(sv_frame_t startFrame, sv_frame_t endFrame)
{
    for (ViewImageCache::iterator i = m_imageCaches.begin();
         i != m_imageCaches.end(); ++i) {

        //!!! when are views removed from the map? on setLayerDormant?
        const LayerGeometryProvider *v = i->first;

#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "SpectrogramLayer::invalidateImageCaches(" 
                  << startFrame << ", " << endFrame << "): view range is "
                  << v->getStartFrame() << ", " << v->getEndFrame()
                  << endl;

        cerr << "Valid area was: " << i->second.validArea.x() << ", "
                  << i->second.validArea.y() << " "
                  << i->second.validArea.width() << "x"
                  << i->second.validArea.height() << endl;
#endif

        if (int(startFrame) > v->getStartFrame()) {
            if (startFrame >= v->getEndFrame()) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
                cerr << "Modified start frame is off right of view" << endl;
#endif
                return;
            }
            int x = v->getXForFrame(startFrame);
#ifdef DEBUG_SPECTROGRAM_REPAINT
            cerr << "clipping from 0 to " << x-1 << endl;
#endif
            if (x > 1) {
                i->second.validArea &=
                    QRect(0, 0, x-1, v->getPaintHeight());
            } else {
                i->second.validArea = QRect();
            }
        } else {
            if (int(endFrame) < v->getStartFrame()) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
                cerr << "Modified end frame is off left of view" << endl;
#endif
                return;
            }
            int x = v->getXForFrame(endFrame);
#ifdef DEBUG_SPECTROGRAM_REPAINT
            cerr << "clipping from " << x+1 << " to " << v->getPaintWidth()
                      << endl;
#endif
            if (x < v->getPaintWidth()) {
                i->second.validArea &=
                    QRect(x+1, 0, v->getPaintWidth()-(x+1), v->getPaintHeight());
            } else {
                i->second.validArea = QRect();
            }
        }

#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "Valid area is now: " << i->second.validArea.x() << ", "
                  << i->second.validArea.y() << " "
                  << i->second.validArea.width() << "x"
                  << i->second.validArea.height() << endl;
#endif
    }
}

void
SpectrogramLayer::preferenceChanged(PropertyContainer::PropertyName name)
{
    SVDEBUG << "SpectrogramLayer::preferenceChanged(" << name << ")" << endl;

    if (name == "Window Type") {
        setWindowType(Preferences::getInstance()->getWindowType());
        return;
    }
    if (name == "Spectrogram Y Smoothing") {
        invalidateImageCaches();
        invalidateMagnitudes();
        emit layerParametersChanged();
    }
    if (name == "Spectrogram X Smoothing") {
        invalidateImageCaches();
        invalidateMagnitudes();
        emit layerParametersChanged();
    }
    if (name == "Tuning Frequency") {
        emit layerParametersChanged();
    }
}

void
SpectrogramLayer::setChannel(int ch)
{
    if (m_channel == ch) return;

    invalidateImageCaches();
    m_channel = ch;
    invalidateFFTModels();

    emit layerParametersChanged();
}

int
SpectrogramLayer::getChannel() const
{
    return m_channel;
}

void
SpectrogramLayer::setWindowSize(int ws)
{
    if (m_windowSize == ws) return;

    invalidateImageCaches();
    
    m_windowSize = ws;
    m_fftSize = ws * (m_zeroPadLevel + 1);
    
    invalidateFFTModels();

    emit layerParametersChanged();
}

int
SpectrogramLayer::getWindowSize() const
{
    return m_windowSize;
}

void
SpectrogramLayer::setWindowHopLevel(int v)
{
    if (m_windowHopLevel == v) return;

    invalidateImageCaches();
    
    m_windowHopLevel = v;
    
    invalidateFFTModels();

    emit layerParametersChanged();

//    fillCache();
}

int
SpectrogramLayer::getWindowHopLevel() const
{
    return m_windowHopLevel;
}

void
SpectrogramLayer::setZeroPadLevel(int v)
{
    if (m_zeroPadLevel == v) return;

    invalidateImageCaches();
    
    m_zeroPadLevel = v;
    m_fftSize = m_windowSize * (v + 1);

    invalidateFFTModels();

    emit layerParametersChanged();
}

int
SpectrogramLayer::getZeroPadLevel() const
{
    return m_zeroPadLevel;
}

void
SpectrogramLayer::setWindowType(WindowType w)
{
    if (m_windowType == w) return;

    invalidateImageCaches();
    
    m_windowType = w;

    invalidateFFTModels();

    emit layerParametersChanged();
}

WindowType
SpectrogramLayer::getWindowType() const
{
    return m_windowType;
}

void
SpectrogramLayer::setGain(float gain)
{
//    SVDEBUG << "SpectrogramLayer::setGain(" << gain << ") (my gain is now "
//	      << m_gain << ")" << endl;

    if (m_gain == gain) return;

    invalidateImageCaches();
    
    m_gain = gain;
    
    emit layerParametersChanged();
}

float
SpectrogramLayer::getGain() const
{
    return m_gain;
}

void
SpectrogramLayer::setThreshold(float threshold)
{
    if (m_threshold == threshold) return;

    invalidateImageCaches();
    
    m_threshold = threshold;

    emit layerParametersChanged();
}

float
SpectrogramLayer::getThreshold() const
{
    return m_threshold;
}

void
SpectrogramLayer::setMinFrequency(int mf)
{
    if (m_minFrequency == mf) return;

//    SVDEBUG << "SpectrogramLayer::setMinFrequency: " << mf << endl;

    invalidateImageCaches();
    invalidateMagnitudes();
    
    m_minFrequency = mf;

    emit layerParametersChanged();
}

int
SpectrogramLayer::getMinFrequency() const
{
    return m_minFrequency;
}

void
SpectrogramLayer::setMaxFrequency(int mf)
{
    if (m_maxFrequency == mf) return;

//    SVDEBUG << "SpectrogramLayer::setMaxFrequency: " << mf << endl;

    invalidateImageCaches();
    invalidateMagnitudes();
    
    m_maxFrequency = mf;
    
    emit layerParametersChanged();
}

int
SpectrogramLayer::getMaxFrequency() const
{
    return m_maxFrequency;
}

void
SpectrogramLayer::setColourRotation(int r)
{
    invalidateImageCaches();

    if (r < 0) r = 0;
    if (r > 256) r = 256;
    int distance = r - m_colourRotation;

    if (distance != 0) {
	rotatePalette(-distance);
	m_colourRotation = r;
    }
    
    emit layerParametersChanged();
}

void
SpectrogramLayer::setColourScale(ColourScale colourScale)
{
    if (m_colourScale == colourScale) return;

    invalidateImageCaches();
    
    m_colourScale = colourScale;
    
    emit layerParametersChanged();
}

SpectrogramLayer::ColourScale
SpectrogramLayer::getColourScale() const
{
    return m_colourScale;
}

void
SpectrogramLayer::setColourMap(int map)
{
    if (m_colourMap == map) return;

    invalidateImageCaches();
    
    m_colourMap = map;
    initialisePalette();

    emit layerParametersChanged();
}

int
SpectrogramLayer::getColourMap() const
{
    return m_colourMap;
}

void
SpectrogramLayer::setFrequencyScale(FrequencyScale frequencyScale)
{
    if (m_frequencyScale == frequencyScale) return;

    invalidateImageCaches();
    m_frequencyScale = frequencyScale;

    emit layerParametersChanged();
}

SpectrogramLayer::FrequencyScale
SpectrogramLayer::getFrequencyScale() const
{
    return m_frequencyScale;
}

void
SpectrogramLayer::setBinDisplay(BinDisplay binDisplay)
{
    if (m_binDisplay == binDisplay) return;

    invalidateImageCaches();
    m_binDisplay = binDisplay;

    emit layerParametersChanged();
}

SpectrogramLayer::BinDisplay
SpectrogramLayer::getBinDisplay() const
{
    return m_binDisplay;
}

void
SpectrogramLayer::setNormalization(Normalization n)
{
    if (m_normalization == n) return;

    invalidateImageCaches();
    invalidateMagnitudes();
    m_normalization = n;

    emit layerParametersChanged();
}

SpectrogramLayer::Normalization
SpectrogramLayer::getNormalization() const
{
    return m_normalization;
}

void
SpectrogramLayer::setLayerDormant(const LayerGeometryProvider *v, bool dormant)
{
    if (dormant) {

#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "SpectrogramLayer::setLayerDormant(" << dormant << ")"
                  << endl;
#endif

        if (isLayerDormant(v)) {
            return;
        }

        Layer::setLayerDormant(v, true);

        const View *view = v->getView();
        
	invalidateImageCaches();

        m_imageCaches.erase(view);

        if (m_fftModels.find(view) != m_fftModels.end()) {

            if (m_sliceableModel == m_fftModels[view]) {
                bool replaced = false;
                for (ViewFFTMap::iterator i = m_fftModels.begin();
                     i != m_fftModels.end(); ++i) {
                    if (i->second != m_sliceableModel) {
                        emit sliceableModelReplaced(m_sliceableModel, i->second);
                        replaced = true;
                        break;
                    }
                }
                if (!replaced) emit sliceableModelReplaced(m_sliceableModel, 0);
            }

            delete m_fftModels[view];
            m_fftModels.erase(view);

            delete m_peakCaches[view];
            m_peakCaches.erase(view);
        }
	
    } else {

        Layer::setLayerDormant(v, false);
    }
}

void
SpectrogramLayer::cacheInvalid()
{
#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "SpectrogramLayer::cacheInvalid()" << endl;
#endif

    invalidateImageCaches();
    invalidateMagnitudes();
}

void
SpectrogramLayer::cacheInvalid(sv_frame_t from, sv_frame_t to)
{
#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "SpectrogramLayer::cacheInvalid(" << from << ", " << to << ")" << endl;
#endif

    invalidateImageCaches(from, to);
    invalidateMagnitudes();
}

bool
SpectrogramLayer::hasLightBackground() const 
{
    return ColourMapper(m_colourMap, 1.f, 255.f).hasLightBackground();
}

void
SpectrogramLayer::initialisePalette()
{
    int formerRotation = m_colourRotation;

    if (m_colourMap == (int)ColourMapper::BlackOnWhite) {
	m_palette.setColour(NO_VALUE, Qt::white);
    } else {
	m_palette.setColour(NO_VALUE, Qt::black);
    }

    ColourMapper mapper(m_colourMap, 1.f, 255.f);
    
    for (int pixel = 1; pixel < 256; ++pixel) {
        m_palette.setColour((unsigned char)pixel, mapper.map(pixel));
    }

    m_crosshairColour = mapper.getContrastingColour();

    m_colourRotation = 0;
    rotatePalette(m_colourRotation - formerRotation);
    m_colourRotation = formerRotation;

    m_drawBuffer = QImage();
}

void
SpectrogramLayer::rotatePalette(int distance)
{
    QColor newPixels[256];

    newPixels[NO_VALUE] = m_palette.getColour(NO_VALUE);

    for (int pixel = 1; pixel < 256; ++pixel) {
	int target = pixel + distance;
	while (target < 1) target += 255;
	while (target > 255) target -= 255;
	newPixels[target] = m_palette.getColour((unsigned char)pixel);
    }

    for (int pixel = 0; pixel < 256; ++pixel) {
	m_palette.setColour((unsigned char)pixel, newPixels[pixel]);
    }

    m_drawBuffer = QImage();
}

unsigned char
SpectrogramLayer::getDisplayValue(LayerGeometryProvider *v, double input) const
{
    int value;

    double min = 0.0;
    double max = 1.0;

    if (m_normalization == NormalizeVisibleArea) {
        min = m_viewMags[v].getMin();
        max = m_viewMags[v].getMax();
    } else if (m_normalization != NormalizeColumns) {
        if (m_colourScale == LinearColourScale //||
//            m_colourScale == MeterColourScale) {
            ) {
            max = 0.1;
        }
    }

    double thresh = -80.0;

    if (max == 0.0) max = 1.0;
    if (max == min) min = max - 0.0001;

    switch (m_colourScale) {
	
    default:
    case LinearColourScale:
        value = int(((input - min) / (max - min)) * 255.0) + 1;
	break;
	
    case MeterColourScale:
        value = AudioLevel::multiplier_to_preview
            ((input - min) / (max - min), 254) + 1;
	break;

    case dBSquaredColourScale:
        input = ((input - min) * (input - min)) / ((max - min) * (max - min));
        if (input > 0.0) {
            input = 10.0 * log10(input);
        } else {
            input = thresh;
        }
        if (min > 0.0) {
            thresh = 10.0 * log10(min * min);
            if (thresh < -80.0) thresh = -80.0;
        }
	input = (input - thresh) / (-thresh);
	if (input < 0.0) input = 0.0;
	if (input > 1.0) input = 1.0;
	value = int(input * 255.0) + 1;
	break;
	
    case dBColourScale:
        //!!! experiment with normalizing the visible area this way.
        //In any case, we need to have some indication of what the dB
        //scale is relative to.
        input = (input - min) / (max - min);
        if (input > 0.0) {
            input = 10.0 * log10(input);
        } else {
            input = thresh;
        }
        if (min > 0.0) {
            thresh = 10.0 * log10(min);
            if (thresh < -80.0) thresh = -80.0;
        }
	input = (input - thresh) / (-thresh);
	if (input < 0.0) input = 0.0;
	if (input > 1.0) input = 1.0;
	value = int(input * 255.0) + 1;
	break;
	
    case PhaseColourScale:
	value = int((input * 127.0 / M_PI) + 128);
	break;
    }

    if (value > UCHAR_MAX) value = UCHAR_MAX;
    if (value < 0) value = 0;
    return (unsigned char)value;
}

double
SpectrogramLayer::getEffectiveMinFrequency() const
{
    sv_samplerate_t sr = m_model->getSampleRate();
    double minf = double(sr) / m_fftSize;

    if (m_minFrequency > 0.0) {
	int minbin = int((double(m_minFrequency) * m_fftSize) / sr + 0.01);
	if (minbin < 1) minbin = 1;
	minf = minbin * sr / m_fftSize;
    }

    return minf;
}

double
SpectrogramLayer::getEffectiveMaxFrequency() const
{
    sv_samplerate_t sr = m_model->getSampleRate();
    double maxf = double(sr) / 2;

    if (m_maxFrequency > 0.0) {
	int maxbin = int((double(m_maxFrequency) * m_fftSize) / sr + 0.1);
	if (maxbin > m_fftSize / 2) maxbin = m_fftSize / 2;
	maxf = maxbin * sr / m_fftSize;
    }

    return maxf;
}

bool
SpectrogramLayer::getYBinRange(LayerGeometryProvider *v, int y, double &q0, double &q1) const
{
    Profiler profiler("SpectrogramLayer::getYBinRange");
    
    int h = v->getPaintHeight();
    if (y < 0 || y >= h) return false;

    sv_samplerate_t sr = m_model->getSampleRate();
    double minf = getEffectiveMinFrequency();
    double maxf = getEffectiveMaxFrequency();

    bool logarithmic = (m_frequencyScale == LogFrequencyScale);

    q0 = v->getFrequencyForY(y, minf, maxf, logarithmic);
    q1 = v->getFrequencyForY(y - 1, minf, maxf, logarithmic);

    // Now map these on to ("proportions of") actual bins, using raw
    // FFT size (unsmoothed)

    q0 = (q0 * m_fftSize) / sr;
    q1 = (q1 * m_fftSize) / sr;

    return true;
}

bool
SpectrogramLayer::getSmoothedYBinRange(LayerGeometryProvider *v, int y, double &q0, double &q1) const
{
    Profiler profiler("SpectrogramLayer::getSmoothedYBinRange");

    int h = v->getPaintHeight();
    if (y < 0 || y >= h) return false;

    sv_samplerate_t sr = m_model->getSampleRate();
    double minf = getEffectiveMinFrequency();
    double maxf = getEffectiveMaxFrequency();

    bool logarithmic = (m_frequencyScale == LogFrequencyScale);

    q0 = v->getFrequencyForY(y, minf, maxf, logarithmic);
    q1 = v->getFrequencyForY(y - 1, minf, maxf, logarithmic);

    // Now map these on to ("proportions of") actual bins, using raw
    // FFT size (unsmoothed)

    q0 = (q0 * getFFTSize(v)) / sr;
    q1 = (q1 * getFFTSize(v)) / sr;

    return true;
}
    
bool
SpectrogramLayer::getXBinRange(LayerGeometryProvider *v, int x, double &s0, double &s1) const
{
    sv_frame_t modelStart = m_model->getStartFrame();
    sv_frame_t modelEnd = m_model->getEndFrame();

    // Each pixel column covers an exact range of sample frames:
    sv_frame_t f0 = v->getFrameForX(x) - modelStart;
    sv_frame_t f1 = v->getFrameForX(x + 1) - modelStart - 1;

    if (f1 < int(modelStart) || f0 > int(modelEnd)) {
	return false;
    }
      
    // And that range may be drawn from a possibly non-integral
    // range of spectrogram windows:

    int windowIncrement = getWindowIncrement();
    s0 = double(f0) / windowIncrement;
    s1 = double(f1) / windowIncrement;

    return true;
}
 
bool
SpectrogramLayer::getXBinSourceRange(LayerGeometryProvider *v, int x, RealTime &min, RealTime &max) const
{
    double s0 = 0, s1 = 0;
    if (!getXBinRange(v, x, s0, s1)) return false;
    
    int s0i = int(s0 + 0.001);
    int s1i = int(s1);

    int windowIncrement = getWindowIncrement();
    int w0 = s0i * windowIncrement - (m_windowSize - windowIncrement)/2;
    int w1 = s1i * windowIncrement + windowIncrement +
	(m_windowSize - windowIncrement)/2 - 1;
    
    min = RealTime::frame2RealTime(w0, m_model->getSampleRate());
    max = RealTime::frame2RealTime(w1, m_model->getSampleRate());
    return true;
}

bool
SpectrogramLayer::getYBinSourceRange(LayerGeometryProvider *v, int y, double &freqMin, double &freqMax)
const
{
    double q0 = 0, q1 = 0;
    if (!getYBinRange(v, y, q0, q1)) return false;

    int q0i = int(q0 + 0.001);
    int q1i = int(q1);

    sv_samplerate_t sr = m_model->getSampleRate();

    for (int q = q0i; q <= q1i; ++q) {
	if (q == q0i) freqMin = (sr * q) / m_fftSize;
	if (q == q1i) freqMax = (sr * (q+1)) / m_fftSize;
    }
    return true;
}

bool
SpectrogramLayer::getAdjustedYBinSourceRange(LayerGeometryProvider *v, int x, int y,
					     double &freqMin, double &freqMax,
					     double &adjFreqMin, double &adjFreqMax)
const
{
    if (!m_model || !m_model->isOK() || !m_model->isReady()) {
	return false;
    }

    FFTModel *fft = getFFTModel(v);
    if (!fft) return false;

    double s0 = 0, s1 = 0;
    if (!getXBinRange(v, x, s0, s1)) return false;

    double q0 = 0, q1 = 0;
    if (!getYBinRange(v, y, q0, q1)) return false;

    int s0i = int(s0 + 0.001);
    int s1i = int(s1);

    int q0i = int(q0 + 0.001);
    int q1i = int(q1);

    sv_samplerate_t sr = m_model->getSampleRate();

    bool haveAdj = false;

    bool peaksOnly = (m_binDisplay == PeakBins ||
		      m_binDisplay == PeakFrequencies);

    for (int q = q0i; q <= q1i; ++q) {

	for (int s = s0i; s <= s1i; ++s) {

	    double binfreq = (double(sr) * q) / m_windowSize;
	    if (q == q0i) freqMin = binfreq;
	    if (q == q1i) freqMax = binfreq;

	    if (peaksOnly && !fft->isLocalPeak(s, q)) continue;

	    if (!fft->isOverThreshold(s, q, float(m_threshold * double(m_fftSize)/2.0))) continue;

            double freq = binfreq;
	    
	    if (s < int(fft->getWidth()) - 1) {

                fft->estimateStableFrequency(s, q, freq);
	    
		if (!haveAdj || freq < adjFreqMin) adjFreqMin = freq;
		if (!haveAdj || freq > adjFreqMax) adjFreqMax = freq;

		haveAdj = true;
	    }
	}
    }

    if (!haveAdj) {
	adjFreqMin = adjFreqMax = 0.0;
    }

    return haveAdj;
}
    
bool
SpectrogramLayer::getXYBinSourceRange(LayerGeometryProvider *v, int x, int y,
				      double &min, double &max,
				      double &phaseMin, double &phaseMax) const
{
    if (!m_model || !m_model->isOK() || !m_model->isReady()) {
	return false;
    }

    double q0 = 0, q1 = 0;
    if (!getYBinRange(v, y, q0, q1)) return false;

    double s0 = 0, s1 = 0;
    if (!getXBinRange(v, x, s0, s1)) return false;
    
    int q0i = int(q0 + 0.001);
    int q1i = int(q1);

    int s0i = int(s0 + 0.001);
    int s1i = int(s1);

    bool rv = false;

    int zp = getZeroPadLevel(v);
    q0i *= zp + 1;
    q1i *= zp + 1;

    FFTModel *fft = getFFTModel(v);

    if (fft) {

        int cw = fft->getWidth();
        int ch = fft->getHeight();

        min = 0.0;
        max = 0.0;
        phaseMin = 0.0;
        phaseMax = 0.0;
        bool have = false;

        for (int q = q0i; q <= q1i; ++q) {
            for (int s = s0i; s <= s1i; ++s) {
                if (s >= 0 && q >= 0 && s < cw && q < ch) {

                    double value;

                    value = fft->getPhaseAt(s, q);
                    if (!have || value < phaseMin) { phaseMin = value; }
                    if (!have || value > phaseMax) { phaseMax = value; }

                    value = fft->getMagnitudeAt(s, q) / (m_fftSize/2.0);
                    if (!have || value < min) { min = value; }
                    if (!have || value > max) { max = value; }
                    
                    have = true;
                }	
            }
        }
        
        if (have) {
            rv = true;
        }
    }

    return rv;
}
   
int
SpectrogramLayer::getZeroPadLevel(const LayerGeometryProvider *v) const
{
    //!!! tidy all this stuff

    if (m_binDisplay != AllBins) return 0;

    Preferences::SpectrogramSmoothing smoothing = 
        Preferences::getInstance()->getSpectrogramSmoothing();
    
    if (smoothing == Preferences::NoSpectrogramSmoothing ||
        smoothing == Preferences::SpectrogramInterpolated) return 0;

    if (m_frequencyScale == LogFrequencyScale) return 3;

    sv_samplerate_t sr = m_model->getSampleRate();
    
    int maxbin = m_fftSize / 2;
    if (m_maxFrequency > 0) {
	maxbin = int((double(m_maxFrequency) * m_fftSize) / sr + 0.1);
	if (maxbin > m_fftSize / 2) maxbin = m_fftSize / 2;
    }

    int minbin = 1;
    if (m_minFrequency > 0) {
	minbin = int((double(m_minFrequency) * m_fftSize) / sr + 0.1);
	if (minbin < 1) minbin = 1;
	if (minbin >= maxbin) minbin = maxbin - 1;
    }

    double perPixel =
        double(v->getPaintHeight()) /
        double((maxbin - minbin) / (m_zeroPadLevel + 1));

    if (perPixel > 2.8) {
        return 3; // 4x oversampling
    } else if (perPixel > 1.5) {
        return 1; // 2x
    } else {
        return 0; // 1x
    }
}

int
SpectrogramLayer::getFFTSize(const LayerGeometryProvider *v) const
{
    return m_fftSize * (getZeroPadLevel(v) + 1);
}
	
FFTModel *
SpectrogramLayer::getFFTModel(const LayerGeometryProvider *v) const
{
    if (!m_model) return 0;

    int fftSize = getFFTSize(v);

    const View *view = v->getView();
    
    if (m_fftModels.find(view) != m_fftModels.end()) {
        if (m_fftModels[view] == 0) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
            cerr << "SpectrogramLayer::getFFTModel(" << v << "): Found null model" << endl;
#endif
            return 0;
        }
        if (m_fftModels[view]->getHeight() != fftSize / 2 + 1) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
            cerr << "SpectrogramLayer::getFFTModel(" << v << "): Found a model with the wrong height (" << m_fftModels[view]->getHeight() << ", wanted " << (fftSize / 2 + 1) << ")" << endl;
#endif
            delete m_fftModels[view];
            m_fftModels.erase(view);
            delete m_peakCaches[view];
            m_peakCaches.erase(view);
        } else {
#ifdef DEBUG_SPECTROGRAM_REPAINT
            cerr << "SpectrogramLayer::getFFTModel(" << v << "): Found a good model of height " << m_fftModels[view]->getHeight() << endl;
#endif
            return m_fftModels[view];
        }
    }

    if (m_fftModels.find(view) == m_fftModels.end()) {

        FFTModel *model = new FFTModel(m_model,
                                       m_channel,
                                       m_windowType,
                                       m_windowSize,
                                       getWindowIncrement(),
                                       fftSize);

        if (!model->isOK()) {
            QMessageBox::critical
                (0, tr("FFT cache failed"),
                 tr("Failed to create the FFT model for this spectrogram.\n"
                    "There may be insufficient memory or disc space to continue."));
            delete model;
            m_fftModels[view] = 0;
            return 0;
        }

        if (!m_sliceableModel) {
#ifdef DEBUG_SPECTROGRAM
            cerr << "SpectrogramLayer: emitting sliceableModelReplaced(0, " << model << ")" << endl;
#endif
            ((SpectrogramLayer *)this)->sliceableModelReplaced(0, model);
            m_sliceableModel = model;
        }

        m_fftModels[view] = model;
    }

    return m_fftModels[view];
}

Dense3DModelPeakCache *
SpectrogramLayer::getPeakCache(const LayerGeometryProvider *v) const
{
    const View *view = v->getView();
    if (!m_peakCaches[view]) {
        FFTModel *f = getFFTModel(v);
        if (!f) return 0;
        m_peakCaches[view] = new Dense3DModelPeakCache(f, 8);
    }
    return m_peakCaches[view];
}

const Model *
SpectrogramLayer::getSliceableModel() const
{
    if (m_sliceableModel) return m_sliceableModel;
    if (m_fftModels.empty()) return 0;
    m_sliceableModel = m_fftModels.begin()->second;
    return m_sliceableModel;
}

void
SpectrogramLayer::invalidateFFTModels()
{
    for (ViewFFTMap::iterator i = m_fftModels.begin();
         i != m_fftModels.end(); ++i) {
        delete i->second;
    }
    for (PeakCacheMap::iterator i = m_peakCaches.begin();
         i != m_peakCaches.end(); ++i) {
        delete i->second;
    }
    
    m_fftModels.clear();
    m_peakCaches.clear();

    if (m_sliceableModel) {
        cerr << "SpectrogramLayer: emitting sliceableModelReplaced(" << m_sliceableModel << ", 0)" << endl;
        emit sliceableModelReplaced(m_sliceableModel, 0);
        m_sliceableModel = 0;
    }
}

void
SpectrogramLayer::invalidateMagnitudes()
{
    m_viewMags.clear();
    for (std::vector<MagnitudeRange>::iterator i = m_columnMags.begin();
         i != m_columnMags.end(); ++i) {
        *i = MagnitudeRange();
    }
}

bool
SpectrogramLayer::updateViewMagnitudes(LayerGeometryProvider *v) const
{
    MagnitudeRange mag;

    int x0 = 0, x1 = v->getPaintWidth();
    double s00 = 0, s01 = 0, s10 = 0, s11 = 0;
    
    if (!getXBinRange(v, x0, s00, s01)) {
        s00 = s01 = double(m_model->getStartFrame()) / getWindowIncrement();
    }

    if (!getXBinRange(v, x1, s10, s11)) {
        s10 = s11 = double(m_model->getEndFrame()) / getWindowIncrement();
    }

    int s0 = int(std::min(s00, s10) + 0.0001);
    int s1 = int(std::max(s01, s11) + 0.0001);

//    SVDEBUG << "SpectrogramLayer::updateViewMagnitudes: x0 = " << x0 << ", x1 = " << x1 << ", s00 = " << s00 << ", s11 = " << s11 << " s0 = " << s0 << ", s1 = " << s1 << endl;

    if (int(m_columnMags.size()) <= s1) {
        m_columnMags.resize(s1 + 1);
    }

    for (int s = s0; s <= s1; ++s) {
        if (m_columnMags[s].isSet()) {
            mag.sample(m_columnMags[s]);
        }
    }

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "SpectrogramLayer::updateViewMagnitudes returning from cols "
              << s0 << " -> " << s1 << " inclusive" << endl;
#endif

    if (!mag.isSet()) return false;
    if (mag == m_viewMags[v]) return false;
    m_viewMags[v] = mag;
    return true;
}

void
SpectrogramLayer::setSynchronousPainting(bool synchronous)
{
    m_synchronous = synchronous;
}

void
SpectrogramLayer::paint(LayerGeometryProvider *v, QPainter &paint, QRect rect) const
{
    // What a lovely, old-fashioned function this is.
    // It's practically FORTRAN 77 in its clarity and linearity.

    Profiler profiler("SpectrogramLayer::paint", false);

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "SpectrogramLayer::paint(): m_model is " << m_model << ", zoom level is " << v->getZoomLevel() << endl;
    
    cerr << "rect is " << rect.x() << "," << rect.y() << " " << rect.width() << "x" << rect.height() << endl;
#endif

    sv_frame_t startFrame = v->getStartFrame();

    if (!m_model || !m_model->isOK() || !m_model->isReady()) {
	return;
    }

    if (isLayerDormant(v)) {
	SVDEBUG << "SpectrogramLayer::paint(): Layer is dormant, making it undormant again" << endl;
    }

    // Need to do this even if !isLayerDormant, as that could mean v
    // is not in the dormancy map at all -- we need it to be present
    // and accountable for when determining whether we need the cache
    // in the cache-fill thread above.
    //!!! no inter use cache-fill thread
    const_cast<SpectrogramLayer *>(this)->Layer::setLayerDormant(v, false);

    int fftSize = getFFTSize(v);

    const View *view = v->getView();
    
    ImageCache &cache = m_imageCaches[view];

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "SpectrogramLayer::paint(): image cache valid area " << cache.

validArea.x() << ", " << cache.validArea.y() << ", " << cache.validArea.width() << "x" << cache.validArea.height() << endl;
#endif

    int zoomLevel = v->getZoomLevel();

    int x0 = 0;
    int x1 = v->getPaintWidth();

    bool recreateWholeImageCache = true;

    x0 = rect.left();
    x1 = rect.right() + 1;

    if (updateViewMagnitudes(v)) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "SpectrogramLayer: magnitude range changed to [" << m_viewMags[v].getMin() << "->" << m_viewMags[v].getMax() << "]" << endl;
#endif
        if (m_normalization == NormalizeVisibleArea) {
            cache.validArea = QRect();
        }
    }

    if (cache.zoomLevel != zoomLevel) {
        // no matter what we do with the cache, we'll need to
        // recalculate our paint width again because each block will
        // take a different time to render from previously
        m_lastPaintBlockWidth = 0;
    }
    
    if (cache.validArea.width() > 0) {

        int cw = cache.image.width();
        int ch = cache.image.height();
        
	if (int(cache.zoomLevel) == zoomLevel &&
	    cw == v->getPaintWidth() &&
	    ch == v->getPaintHeight()) {

            // cache size and zoom level exactly match the view
            
	    if (v->getXForFrame(cache.startFrame) ==
		v->getXForFrame(startFrame) &&
                cache.validArea.x() <= x0 &&
                cache.validArea.x() + cache.validArea.width() >= x1) {

                // and cache begins at the right frame, so use it whole
                
#ifdef DEBUG_SPECTROGRAM_REPAINT
		cerr << "SpectrogramLayer: image cache good" << endl;
#endif

		paint.drawImage(rect, cache.image, rect);

                illuminateLocalFeatures(v, paint);
		return;

	    } else {

                // cache doesn't begin at the right frame or doesn't
                // contain the complete view, but might be scrollable
                // or partially usable
                
#ifdef DEBUG_SPECTROGRAM_REPAINT
		cerr << "SpectrogramLayer: image cache partially OK" << endl;
#endif

		recreateWholeImageCache = false;

		int dx = v->getXForFrame(cache.startFrame) -
		         v->getXForFrame(startFrame);

#ifdef DEBUG_SPECTROGRAM_REPAINT
		cerr << "SpectrogramLayer: dx = " << dx << " (image cache " << cw << "x" << ch << ")" << endl;
#endif

		if (dx != 0 &&
                    dx > -cw &&
                    dx <  cw) {

                    // cache is scrollable, scroll it
                    
                    int dxp = dx;
                    if (dxp < 0) dxp = -dxp;
                    size_t copy = (cw - dxp) * sizeof(QRgb);
                    for (int y = 0; y < ch; ++y) {
                        QRgb *line = (QRgb *)cache.image.scanLine(y);
                        if (dx < 0) {
                            memmove(line, line + dxp, copy);
                        } else {
                            memmove(line + dxp, line, copy);
                        }
                    }

                    // and calculate its new valid area
                    
                    int px = cache.validArea.x();
                    int pw = cache.validArea.width();

		    if (dx < 0) {
			x0 = cw + dx;
			x1 = cw;
                        px += dx;
                        if (px < 0) {
                            pw += px;
                            px = 0;
                            if (pw < 0) pw = 0;
                        }
		    } else {
			x0 = 0;
			x1 = dx;
                        px += dx;
                        if (px + pw > cw) {
                            pw = int(cw) - px;
                            if (pw < 0) pw = 0;
                        }
		    }
                    
                    cache.validArea =
                        QRect(px, cache.validArea.y(),
                              pw, cache.validArea.height());

#ifdef DEBUG_SPECTROGRAM_REPAINT
                    cerr << "valid area now "
                              << px << "," << cache.validArea.y()
                              << " " << pw << "x" << cache.validArea.height()
                              << endl;
#endif

                } else if (dx != 0) {

                    // we've moved too far from the cached area for it
                    // to be of use

#ifdef DEBUG_SPECTROGRAM_REPAINT
                    cerr << "dx == " << dx << ": scrolled too far for cache to be useful" << endl;
#endif

                    cache.validArea = QRect();
                    recreateWholeImageCache = true;
                }
	    }
	} else {
#ifdef DEBUG_SPECTROGRAM_REPAINT
	    cerr << "SpectrogramLayer: image cache useless" << endl;
            if (int(cache.zoomLevel) != zoomLevel) {
                cerr << "(cache zoomLevel " << cache.zoomLevel
                          << " != " << zoomLevel << ")" << endl;
            }
            if (cw != v->getPaintWidth()) {
                cerr << "(cache width " << cw
                          << " != " << v->getPaintWidth();
            }
            if (ch != v->getPaintHeight()) {
                cerr << "(cache height " << ch
                          << " != " << v->getPaintHeight();
            }
#endif
            cache.validArea = QRect();
	}
    }

    if (recreateWholeImageCache) {
        x0 = 0;
        x1 = v->getPaintWidth();
    }

    auto mainPaintStart = std::chrono::steady_clock::now();

    int paintBlockWidth = m_lastPaintBlockWidth;

    if (m_synchronous) {
        if (paintBlockWidth < x1 - x0) {
            // always paint full width
            paintBlockWidth = x1 - x0;
        }
    } else {
        if (paintBlockWidth == 0) {
            paintBlockWidth = (300000 / zoomLevel);
        } else {
            double lastTime = m_lastPaintTime;
            while (lastTime > 0.2 &&
                   paintBlockWidth > 30) {
                paintBlockWidth /= 2;
                lastTime = lastTime / 2;
            }
            while (lastTime < 0.09 &&
                   paintBlockWidth < std::max(50, 1200000 / zoomLevel) &&
                   paintBlockWidth < 1500) {
                paintBlockWidth *= 2;
                lastTime = lastTime * 2;
            }
        }
        
        if (paintBlockWidth < 20) paintBlockWidth = 20;
    }

//#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "[" << this << "]: last paint width: " << m_lastPaintBlockWidth << ", last paint time: " << m_lastPaintTime << ", new paint width: " << paintBlockWidth << endl;
//#endif

    // We always paint the full height when refreshing the cache.
    // Smaller heights can be used when painting direct from cache
    // (further up in this function), but we want to ensure the cache
    // is coherent without having to worry about vertical matching of
    // required and valid areas as well as horizontal.

    int h = v->getPaintHeight();

    if (cache.validArea.width() > 0) {

        // If part of the cache is known to be valid, select a strip
        // immediately to left or right of the valid part

        //!!! this really needs to be coordinated with the selection
        //!!! of m_drawBuffer boundaries in the bufferBinResolution
        //!!! case below

        int vx0 = 0, vx1 = 0;
        vx0 = cache.validArea.x();
        vx1 = cache.validArea.x() + cache.validArea.width();
        
#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "x0 " << x0 << ", x1 " << x1 << ", vx0 " << vx0 << ", vx1 " << vx1 << ", paintBlockWidth " << paintBlockWidth << endl;
#endif         
        if (x0 < vx0) {
            if (x0 + paintBlockWidth < vx0) {
                x0 = vx0 - paintBlockWidth;
            }
            x1 = vx0;
        } else if (x0 >= vx1) {
            x0 = vx1;
            if (x1 > x0 + paintBlockWidth) {
                x1 = x0 + paintBlockWidth;
            }
        } else {
            // x0 is within the valid area
            if (x1 > vx1) {
                x0 = vx1;
                if (x0 + paintBlockWidth < x1) {
                    x1 = x0 + paintBlockWidth;
                }
            } else {
                x1 = x0; // it's all valid, paint nothing
            }
        }
            
    } else {
        if (x1 > x0 + paintBlockWidth) {
            int sfx = x1;
            if (startFrame < 0) sfx = v->getXForFrame(0);
            if (sfx >= x0 && sfx + paintBlockWidth <= x1) {
                x0 = sfx;
                x1 = x0 + paintBlockWidth;
            } else {
                int mid = (x1 + x0) / 2;
                x0 = mid - paintBlockWidth/2;
                x1 = x0 + paintBlockWidth;
            }
        }
    }

    int repaintWidth = x1 - x0;

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "x0 " << x0 << ", x1 " << x1 << ", w " << w << ", h " << h << endl;
#endif

    sv_samplerate_t sr = m_model->getSampleRate();

    // Set minFreq and maxFreq to the frequency extents of the possibly
    // zero-padded visible bin range, and displayMinFreq and displayMaxFreq
    // to the actual scale frequency extents (presumably not zero padded).

    // If we are zero padding, we want to use the zero-padded
    // equivalents of the bins that we would be using if not zero
    // padded, to avoid spaces at the top and bottom of the display.

    // Note fftSize is the actual zero-padded fft size, m_fftSize the
    // nominal fft size.
    
    int maxbin = m_fftSize / 2;
    if (m_maxFrequency > 0) {
	maxbin = int((double(m_maxFrequency) * m_fftSize) / sr + 0.001);
	if (maxbin > m_fftSize / 2) maxbin = m_fftSize / 2;
    }

    int minbin = 1;
    if (m_minFrequency > 0) {
	minbin = int((double(m_minFrequency) * m_fftSize) / sr + 0.001);
//        cerr << "m_minFrequency = " << m_minFrequency << " -> minbin = " << minbin << endl;
	if (minbin < 1) minbin = 1;
	if (minbin >= maxbin) minbin = maxbin - 1;
    }

    int zpl = getZeroPadLevel(v) + 1;
    minbin = minbin * zpl;
    maxbin = (maxbin + 1) * zpl - 1;

    double minFreq = (double(minbin) * sr) / fftSize;
    double maxFreq = (double(maxbin) * sr) / fftSize;

    double displayMinFreq = minFreq;
    double displayMaxFreq = maxFreq;

    if (fftSize != m_fftSize) {
        displayMinFreq = getEffectiveMinFrequency();
        displayMaxFreq = getEffectiveMaxFrequency();
    }

//    cerr << "(giving actual minFreq " << minFreq << " and display minFreq " << displayMinFreq << ")" << endl;

    int increment = getWindowIncrement();
    
    bool logarithmic = (m_frequencyScale == LogFrequencyScale);
/*
    double yforbin[maxbin - minbin + 1];

    for (int q = minbin; q <= maxbin; ++q) {
        double f0 = (double(q) * sr) / fftSize;
        yforbin[q - minbin] =
            v->getYForFrequency(f0, displayMinFreq, displayMaxFreq,
                                logarithmic);
    }
*/
    MagnitudeRange overallMag = m_viewMags[v];
    bool overallMagChanged = false;

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << ((double(v->getFrameForX(1) - v->getFrameForX(0))) / increment) << " bin(s) per pixel" << endl;
#endif

    if (repaintWidth == 0) {
        SVDEBUG << "*** NOTE: repaintWidth == 0" << endl;
    }

    Profiler outerprof("SpectrogramLayer::paint: all cols");

    // The draw buffer contains a fragment at either our pixel
    // resolution (if there is more than one time-bin per pixel) or
    // time-bin resolution (if a time-bin spans more than one pixel).
    // We need to ensure that it starts and ends at points where a
    // time-bin boundary occurs at an exact pixel boundary, and with a
    // certain amount of overlap across existing pixels so that we can
    // scale and draw from it without smoothing errors at the edges.

    // If (getFrameForX(x) / increment) * increment ==
    // getFrameForX(x), then x is a time-bin boundary.  We want two
    // such boundaries at either side of the draw buffer -- one which
    // we draw up to, and one which we subsequently crop at.

    bool bufferBinResolution = false;
    if (increment > zoomLevel) bufferBinResolution = true;

    sv_frame_t leftBoundaryFrame = -1, leftCropFrame = -1;
    sv_frame_t rightBoundaryFrame = -1, rightCropFrame = -1;

    int bufwid;

    if (bufferBinResolution) {

        for (int x = x0; ; --x) {
            sv_frame_t f = v->getFrameForX(x);
            if ((f / increment) * increment == f) {
                if (leftCropFrame == -1) leftCropFrame = f;
                else if (x < x0 - 2) {
                    leftBoundaryFrame = f;
                    break;
                }
            }
        }
        for (int x = x0 + repaintWidth; ; ++x) {
            sv_frame_t f = v->getFrameForX(x);
            if ((f / increment) * increment == f) {
                if (rightCropFrame == -1) rightCropFrame = f;
                else if (x > x0 + repaintWidth + 2) {
                    rightBoundaryFrame = f;
                    break;
                }
            }
        }
#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "Left: crop: " << leftCropFrame << " (bin " << leftCropFrame/increment << "); boundary: " << leftBoundaryFrame << " (bin " << leftBoundaryFrame/increment << ")" << endl;
        cerr << "Right: crop: " << rightCropFrame << " (bin " << rightCropFrame/increment << "); boundary: " << rightBoundaryFrame << " (bin " << rightBoundaryFrame/increment << ")" << endl;
#endif

        bufwid = int((rightBoundaryFrame - leftBoundaryFrame) / increment);

    } else {
        
        bufwid = repaintWidth;
    }

    vector<int> binforx(bufwid);
    vector<double> binfory(h);
    
    bool usePeaksCache = false;

    if (bufferBinResolution) {
        for (int x = 0; x < bufwid; ++x) {
            binforx[x] = int(leftBoundaryFrame / increment) + x;
//            cerr << "binforx[" << x << "] = " << binforx[x] << endl;
        }
        m_drawBuffer = QImage(bufwid, h, QImage::Format_Indexed8);
    } else {
        for (int x = 0; x < bufwid; ++x) {
            double s0 = 0, s1 = 0;
            if (getXBinRange(v, x + x0, s0, s1)) {
                binforx[x] = int(s0 + 0.0001);
            } else {
                binforx[x] = -1; //???
            }
        }
        if (m_drawBuffer.width() < bufwid || m_drawBuffer.height() < h) {
            m_drawBuffer = QImage(bufwid, h, QImage::Format_Indexed8);
        }
        usePeaksCache = (increment * 8) < zoomLevel;
        if (m_colourScale == PhaseColourScale) usePeaksCache = false;
    }

// No longer exists in Qt5:    m_drawBuffer.setNumColors(256);
    for (int pixel = 0; pixel < 256; ++pixel) {
        m_drawBuffer.setColor((unsigned char)pixel,
                              m_palette.getColour((unsigned char)pixel).rgb());
    }

    m_drawBuffer.fill(0);
    int attainedBufwid = bufwid;
    
    if (m_binDisplay != PeakFrequencies) {

        for (int y = 0; y < h; ++y) {
            double q0 = 0, q1 = 0;
            if (!getSmoothedYBinRange(v, h-y-1, q0, q1)) {
                binfory[y] = -1;
            } else {
                binfory[y] = q0;
            }
        }

        attainedBufwid = 
            paintDrawBuffer(v, bufwid, h, binforx, binfory, usePeaksCache,
                            overallMag, overallMagChanged);

    } else {

        attainedBufwid = 
            paintDrawBufferPeakFrequencies(v, bufwid, h, binforx,
                                           minbin, maxbin,
                                           displayMinFreq, displayMaxFreq,
                                           logarithmic,
                                           overallMag, overallMagChanged);
    }

    int failedToRepaint = bufwid - attainedBufwid;
    if (failedToRepaint < 0) {
        cerr << "WARNING: failedToRepaint < 0 (= " << failedToRepaint << ")"
             << endl;
        failedToRepaint = 0;
    }
    
    if (overallMagChanged) {
        m_viewMags[v] = overallMag;
#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "Overall mag is now [" << m_viewMags[v].getMin() << "->" << m_viewMags[v].getMax() << "] - will be updating" << endl;
#endif
    }

    outerprof.end();

    Profiler profiler2("SpectrogramLayer::paint: draw image");

    if (recreateWholeImageCache) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "Recreating image cache: width = " << v->getPaintWidth()
                  << ", height = " << h << endl;
#endif
	cache.image = QImage(v->getPaintWidth(), h, QImage::Format_ARGB32_Premultiplied);
    }

    if (repaintWidth > 0) {

#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "Painting " << repaintWidth << "x" << h
                  << " from draw buffer at " << 0 << "," << 0
                  << " to " << repaintWidth << "x" << h << " on cache at "
                  << x0 << "," << 0 << endl;
#endif

        QPainter cachePainter(&cache.image);

        if (bufferBinResolution) {
            int scaledLeft = v->getXForFrame(leftBoundaryFrame);
            int scaledRight = v->getXForFrame(rightBoundaryFrame);
#ifdef DEBUG_SPECTROGRAM_REPAINT
            cerr << "Rescaling image from " << bufwid
                 << "x" << h << " to "
                 << scaledRight-scaledLeft << "x" << h << endl;
#endif
            Preferences::SpectrogramXSmoothing xsmoothing = 
                Preferences::getInstance()->getSpectrogramXSmoothing();
//            SVDEBUG << "xsmoothing == " << xsmoothing << endl;
            QImage scaled = m_drawBuffer.scaled
                (scaledRight - scaledLeft, h,
                 Qt::IgnoreAspectRatio,
                 ((xsmoothing == Preferences::SpectrogramXInterpolated) ?
                  Qt::SmoothTransformation : Qt::FastTransformation));
            int scaledLeftCrop = v->getXForFrame(leftCropFrame);
            int scaledRightCrop = v->getXForFrame(rightCropFrame);
#ifdef DEBUG_SPECTROGRAM_REPAINT
            cerr << "Drawing image region of width " << scaledRightCrop - scaledLeftCrop << " to "
                 << scaledLeftCrop << " from " << scaledLeftCrop - scaledLeft << endl;
#endif
            cachePainter.drawImage
                (QRect(scaledLeftCrop, 0,
                       scaledRightCrop - scaledLeftCrop, h),
                 scaled,
                 QRect(scaledLeftCrop - scaledLeft, 0,
                       scaledRightCrop - scaledLeftCrop, h));

        } else {

            cachePainter.drawImage(QRect(x0, 0, repaintWidth, h),
                                   m_drawBuffer,
                                   QRect(0, 0, repaintWidth, h));
        }

        cachePainter.end();
    }

    // update cache valid area based on painted area
    if (cache.validArea.width() > 0) {
        
        int left = std::min(cache.validArea.x(), x0);

        int wid  = std::max(cache.validArea.x() + cache.validArea.width() - left,
                            x1 - left);

        wid = wid - failedToRepaint;
        if (wid < 0) wid = 0;
        
        cache.validArea = QRect
            (left, cache.validArea.y(), wid, cache.validArea.height());

#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "Valid area becomes " << cache.validArea.x()
                  << ", " << cache.validArea.y() << ", "
                  << cache.validArea.width() << "x"
                  << cache.validArea.height() << endl;
#endif

    } else {

        cache.validArea = QRect(x0, 0, x1 - x0, h);

#ifdef DEBUG_SPECTROGRAM_REPAINT
        cerr << "Valid area becomes " << x0 << ", 0, " << (x1-x0)
                  << "x" << h << endl;
#endif
    }

    QRect pr = rect & cache.validArea;

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "Painting " << pr.width() << "x" << pr.height()
              << " from cache at " << pr.x() << "," << pr.y()
              << " to window" << endl;
#endif

    paint.drawImage(pr.x(), pr.y(), cache.image,
                    pr.x(), pr.y(), pr.width(), pr.height());

    cache.startFrame = startFrame;
    cache.zoomLevel = zoomLevel;

    if (!m_synchronous) {

        if ((m_normalization != NormalizeVisibleArea) || !overallMagChanged) {
    
            if (cache.validArea.x() > 0) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
                cerr << "SpectrogramLayer::paint() updating left (0, "
                          << cache.validArea.x() << ")" << endl;
#endif
                v->getView()->update(0, 0, cache.validArea.x(), h);
            }
            
            if (cache.validArea.x() + cache.validArea.width() <
                cache.image.width()) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
                cerr << "SpectrogramLayer::paint() updating right ("
                          << cache.validArea.x() + cache.validArea.width()
                          << ", "
                          << cache.image.width() - (cache.validArea.x() +
                                                     cache.validArea.width())
                          << ")" << endl;
#endif
                v->getView()->update
                    (cache.validArea.x() + cache.validArea.width(),
                     0,
                     cache.image.width() - (cache.validArea.x() +
                                            cache.validArea.width()),
                     h);
            }
        } else {
            // overallMagChanged
            cerr << "\noverallMagChanged - updating all\n" << endl;
            cache.validArea = QRect();
            v->getView()->update();
        }
    }

    illuminateLocalFeatures(v, paint);

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "SpectrogramLayer::paint() returning" << endl;
#endif

    if (!m_synchronous) {
        auto mainPaintEnd = std::chrono::steady_clock::now();
        auto diff = mainPaintEnd - mainPaintStart;
        m_lastPaintTime = std::chrono::duration<double>(diff).count();
        m_lastPaintBlockWidth = paintBlockWidth;
    }
}

int
SpectrogramLayer::paintDrawBufferPeakFrequencies(LayerGeometryProvider *v,
                                                 int w,
                                                 int h,
                                                 const vector<int> &binforx,
                                                 int minbin,
                                                 int maxbin,
                                                 double displayMinFreq,
                                                 double displayMaxFreq,
                                                 bool logarithmic,
                                                 MagnitudeRange &overallMag,
                                                 bool &overallMagChanged) const
{
    Profiler profiler("SpectrogramLayer::paintDrawBufferPeakFrequencies");

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "minbin " << minbin << ", maxbin " << maxbin << "; w " << w << ", h " << h << endl;
#endif
    if (minbin < 0) minbin = 0;
    if (maxbin < 0) maxbin = minbin+1;

    FFTModel *fft = getFFTModel(v);
    if (!fft) return 0;

    FFTModel::PeakSet peakfreqs;

    int psx = -1;

#ifdef __GNUC__
    float values[maxbin - minbin + 1];
#else
    float *values = (float *)alloca((maxbin - minbin + 1) * sizeof(float));
#endif

    for (int x = 0; x < w; ++x) {
        
        if (binforx[x] < 0) continue;

        int sx0 = binforx[x];
        int sx1 = sx0;
        if (x+1 < w) sx1 = binforx[x+1];
        if (sx0 < 0) sx0 = sx1 - 1;
        if (sx0 < 0) continue;
        if (sx1 <= sx0) sx1 = sx0 + 1;

        for (int sx = sx0; sx < sx1; ++sx) {

            if (sx < 0 || sx >= int(fft->getWidth())) continue;

            MagnitudeRange mag;

            if (sx != psx) {
                peakfreqs = fft->getPeakFrequencies(FFTModel::AllPeaks, sx,
                                                    minbin, maxbin - 1);
                if (m_colourScale == PhaseColourScale) {
                    fft->getPhasesAt(sx, values, minbin, maxbin - minbin + 1);
                } else if (m_normalization == NormalizeColumns) {
                    fft->getNormalizedMagnitudesAt(sx, values, minbin, maxbin - minbin + 1);
                } else if (m_normalization == NormalizeHybrid) {
                    fft->getNormalizedMagnitudesAt(sx, values, minbin, maxbin - minbin + 1);
                    double max = fft->getMaximumMagnitudeAt(sx);
                    if (max > 0.f) {
                        for (int i = minbin; i <= maxbin; ++i) {
                            values[i - minbin] = float(values[i - minbin] * log10(max));
                        }
                    }
                } else {
                    fft->getMagnitudesAt(sx, values, minbin, maxbin - minbin + 1);
                }
                psx = sx;
            }

            for (FFTModel::PeakSet::const_iterator pi = peakfreqs.begin();
                 pi != peakfreqs.end(); ++pi) {

                int bin = pi->first;
                double freq = pi->second;

                if (bin < minbin) continue;
                if (bin > maxbin) break;

                double value = values[bin - minbin];

                if (m_colourScale != PhaseColourScale) {
                    if (m_normalization != NormalizeColumns) {
                        value /= (m_fftSize/2.0);
                    }
                    mag.sample(float(value));
                    value *= m_gain;
                }

                double y = v->getYForFrequency
                    (freq, displayMinFreq, displayMaxFreq, logarithmic);

                int iy = int(y + 0.5);
                if (iy < 0 || iy >= h) continue;

                m_drawBuffer.setPixel(x, iy, getDisplayValue(v, value));
            }

            if (mag.isSet()) {
                if (sx >= int(m_columnMags.size())) {
#ifdef DEBUG_SPECTROGRAM
                    cerr << "INTERNAL ERROR: " << sx << " >= "
                              << m_columnMags.size()
                              << " at SpectrogramLayer.cpp::paintDrawBuffer"
                              << endl;
#endif
                } else {
                    m_columnMags[sx].sample(mag);
                    if (overallMag.sample(mag)) overallMagChanged = true;
                }
            }
        }
    }

    return w;
}

int
SpectrogramLayer::paintDrawBuffer(LayerGeometryProvider *v,
                                  int w,
                                  int h,
                                  const vector<int> &binforx,
                                  const vector<double> &binfory,
                                  bool usePeaksCache,
                                  MagnitudeRange &overallMag,
                                  bool &overallMagChanged) const
{
    Profiler profiler("SpectrogramLayer::paintDrawBuffer");

    int minbin = int(binfory[0] + 0.0001);
    int maxbin = int(binfory[h-1]);

#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "paintDrawBuffer: minbin " << minbin << ", maxbin " << maxbin << "; w " << w << ", h " << h << endl;
#endif
    if (minbin < 0) minbin = 0;
    if (maxbin < 0) maxbin = minbin+1;

    DenseThreeDimensionalModel *sourceModel = 0;
    FFTModel *fft = 0;
    int divisor = 1;
#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "Note: bin display = " << m_binDisplay << ", w = " << w << ", binforx[" << w-1 << "] = " << binforx[w-1] << ", binforx[0] = " << binforx[0] << endl;
#endif
    if (usePeaksCache) { //!!!
        sourceModel = getPeakCache(v);
        divisor = 8;//!!!
        minbin = 0;
        maxbin = sourceModel->getHeight();
    } else {
        sourceModel = fft = getFFTModel(v);
    }

    if (!sourceModel) return 0;

    bool interpolate = false;
    Preferences::SpectrogramSmoothing smoothing = 
        Preferences::getInstance()->getSpectrogramSmoothing();
    if (smoothing == Preferences::SpectrogramInterpolated ||
        smoothing == Preferences::SpectrogramZeroPaddedAndInterpolated) {
        if (m_binDisplay != PeakBins &&
            m_binDisplay != PeakFrequencies) {
            interpolate = true;
        }
    }

    int psx = -1;

#ifdef __GNUC__
    float autoarray[maxbin - minbin + 1];
    float peaks[h];
#else
    float *autoarray = (float *)alloca((maxbin - minbin + 1) * sizeof(float));
    float *peaks = (float *)alloca(h * sizeof(float));
#endif

    const float *values = autoarray;
    DenseThreeDimensionalModel::Column c;

    for (int x = 0; x < w; ++x) {
        
        if (binforx[x] < 0) continue;

//        float columnGain = m_gain;
        float columnMax = 0.f;

        int sx0 = binforx[x] / divisor;
        int sx1 = sx0;
        if (x+1 < w) sx1 = binforx[x+1] / divisor;
        if (sx0 < 0) sx0 = sx1 - 1;
        if (sx0 < 0) continue;
        if (sx1 <= sx0) sx1 = sx0 + 1;

        for (int y = 0; y < h; ++y) peaks[y] = 0.f;
            
        for (int sx = sx0; sx < sx1; ++sx) {

#ifdef DEBUG_SPECTROGRAM_REPAINT
//            cerr << "sx = " << sx << endl;
#endif

            if (sx < 0 || sx >= int(sourceModel->getWidth())) continue;

            MagnitudeRange mag;

            if (sx != psx) {
                if (fft) {
#ifdef DEBUG_SPECTROGRAM_REPAINT
                    cerr << "Retrieving column " << sx << " from fft directly" << endl;
#endif
                    if (m_colourScale == PhaseColourScale) {
                        fft->getPhasesAt(sx, autoarray, minbin, maxbin - minbin + 1);
                    } else if (m_normalization == NormalizeColumns) {
                        fft->getNormalizedMagnitudesAt(sx, autoarray, minbin, maxbin - minbin + 1);
                    } else if (m_normalization == NormalizeHybrid) {
                        fft->getNormalizedMagnitudesAt(sx, autoarray, minbin, maxbin - minbin + 1);
                        float max = fft->getMaximumMagnitudeAt(sx);
                        float scale = log10f(max + 1.f);
//                        cout << "sx = " << sx << ", max = " << max << ", log10(max) = " << log10(max) << ", scale = " << scale << endl;
                        for (int i = minbin; i <= maxbin; ++i) {
                            autoarray[i - minbin] *= scale;
                        }
                    } else {
                        fft->getMagnitudesAt(sx, autoarray, minbin, maxbin - minbin + 1);
                    }
                } else {
#ifdef DEBUG_SPECTROGRAM_REPAINT
                    cerr << "Retrieving column " << sx << " from peaks cache" << endl;
#endif
                    c = sourceModel->getColumn(sx);
                    if (m_normalization == NormalizeColumns ||
                        m_normalization == NormalizeHybrid) {
                        for (int y = 0; y < h; ++y) {
                            if (c[y] > columnMax) columnMax = c[y];
                        }
                    }
                    values = c.data() + minbin;
                }
                psx = sx;
            }

            for (int y = 0; y < h; ++y) {

                double sy0 = binfory[y];
                double sy1 = sy0 + 1;
                if (y+1 < h) sy1 = binfory[y+1];

                double value = 0.0;

                if (interpolate && fabs(sy1 - sy0) < 1.0) {

                    double centre = (sy0 + sy1) / 2;
                    double dist = (centre - 0.5) - rint(centre - 0.5);
                    int bin = int(centre);
                    int other = (dist < 0 ? (bin-1) : (bin+1));
                    if (bin < minbin) bin = minbin;
                    if (bin > maxbin) bin = maxbin;
                    if (other < minbin || other > maxbin) other = bin;
                    double prop = 1.0 - fabs(dist);

                    double v0 = values[bin - minbin];
                    double v1 = values[other - minbin];
                    if (m_binDisplay == PeakBins) {
                        if (bin == minbin || bin == maxbin ||
                            v0 < values[bin-minbin-1] ||
                            v0 < values[bin-minbin+1]) v0 = 0.0;
                        if (other == minbin || other == maxbin ||
                            v1 < values[other-minbin-1] ||
                            v1 < values[other-minbin+1]) v1 = 0.0;
                    }
                    if (v0 == 0.0 && v1 == 0.0) continue;
                    value = prop * v0 + (1.0 - prop) * v1;

                    if (m_colourScale != PhaseColourScale) {
                        if (m_normalization != NormalizeColumns &&
                            m_normalization != NormalizeHybrid) {
                            value /= (m_fftSize/2.0);
                        }
                        mag.sample(float(value));
                        value *= m_gain;
                    }

                    peaks[y] = float(value);

                } else {                    

                    int by0 = int(sy0 + 0.0001);
                    int by1 = int(sy1 + 0.0001);
                    if (by1 < by0 + 1) by1 = by0 + 1;

                    for (int bin = by0; bin < by1; ++bin) {

                        value = values[bin - minbin];
                        if (m_binDisplay == PeakBins) {
                            if (bin == minbin || bin == maxbin ||
                                value < values[bin-minbin-1] ||
                                value < values[bin-minbin+1]) continue;
                        }

                        if (m_colourScale != PhaseColourScale) {
                            if (m_normalization != NormalizeColumns &&
                                m_normalization != NormalizeHybrid) {
                                value /= (m_fftSize/2.0);
                            }
                            mag.sample(float(value));
                            value *= m_gain;
                        }

                        if (value > peaks[y]) {
                            peaks[y] = float(value); //!!! not right for phase!
                        }
                    }
                }
            }

            if (mag.isSet()) {
                if (sx >= int(m_columnMags.size())) {
#ifdef DEBUG_SPECTROGRAM
                    cerr << "INTERNAL ERROR: " << sx << " >= "
                              << m_columnMags.size()
                              << " at SpectrogramLayer.cpp::paintDrawBuffer"
                              << endl;
#endif
                } else {
                    m_columnMags[sx].sample(mag);
                    if (overallMag.sample(mag)) overallMagChanged = true;
                }
            }
        }

        for (int y = 0; y < h; ++y) {

            double peak = peaks[y];
            
            if (m_colourScale != PhaseColourScale &&
                (m_normalization == NormalizeColumns ||
                 m_normalization == NormalizeHybrid) &&
                columnMax > 0.f) {
                peak /= columnMax;
                if (m_normalization == NormalizeHybrid) {
                    peak *= log10(columnMax + 1.f);
                }
            }
            
            unsigned char peakpix = getDisplayValue(v, peak);

            m_drawBuffer.setPixel(x, h-y-1, peakpix);
        }
    }

    return w;
}

void
SpectrogramLayer::illuminateLocalFeatures(LayerGeometryProvider *v, QPainter &paint) const
{
    Profiler profiler("SpectrogramLayer::illuminateLocalFeatures");

    QPoint localPos;
    if (!v->shouldIlluminateLocalFeatures(this, localPos) || !m_model) {
        return;
    }

//    cerr << "SpectrogramLayer: illuminateLocalFeatures("
//              << localPos.x() << "," << localPos.y() << ")" << endl;

    double s0, s1;
    double f0, f1;

    if (getXBinRange(v, localPos.x(), s0, s1) &&
        getYBinSourceRange(v, localPos.y(), f0, f1)) {
        
        int s0i = int(s0 + 0.001);
        int s1i = int(s1);
        
        int x0 = v->getXForFrame(s0i * getWindowIncrement());
        int x1 = v->getXForFrame((s1i + 1) * getWindowIncrement());

        int y1 = int(getYForFrequency(v, f1));
        int y0 = int(getYForFrequency(v, f0));
        
//        cerr << "SpectrogramLayer: illuminate "
//                  << x0 << "," << y1 << " -> " << x1 << "," << y0 << endl;
        
        paint.setPen(v->getForeground());

        //!!! should we be using paintCrosshairs for this?

        paint.drawRect(x0, y1, x1 - x0 + 1, y0 - y1 + 1);
    }
}

double
SpectrogramLayer::getYForFrequency(const LayerGeometryProvider *v, double frequency) const
{
    return v->getYForFrequency(frequency,
			       getEffectiveMinFrequency(),
			       getEffectiveMaxFrequency(),
			       m_frequencyScale == LogFrequencyScale);
}

double
SpectrogramLayer::getFrequencyForY(const LayerGeometryProvider *v, int y) const
{
    return v->getFrequencyForY(y,
			       getEffectiveMinFrequency(),
			       getEffectiveMaxFrequency(),
			       m_frequencyScale == LogFrequencyScale);
}

int
SpectrogramLayer::getCompletion(LayerGeometryProvider *v) const
{
    const View *view = v->getView();
    
    if (m_fftModels.find(view) == m_fftModels.end()) return 100;

    int completion = m_fftModels[view]->getCompletion();
#ifdef DEBUG_SPECTROGRAM_REPAINT
    cerr << "SpectrogramLayer::getCompletion: completion = " << completion << endl;
#endif
    return completion;
}

QString
SpectrogramLayer::getError(LayerGeometryProvider *v) const
{
    const View *view = v->getView();
    if (m_fftModels.find(view) == m_fftModels.end()) return "";
    return m_fftModels[view]->getError();
}

bool
SpectrogramLayer::getValueExtents(double &min, double &max,
                                  bool &logarithmic, QString &unit) const
{
    if (!m_model) return false;

    sv_samplerate_t sr = m_model->getSampleRate();
    min = double(sr) / m_fftSize;
    max = double(sr) / 2;
    
    logarithmic = (m_frequencyScale == LogFrequencyScale);
    unit = "Hz";
    return true;
}

bool
SpectrogramLayer::getDisplayExtents(double &min, double &max) const
{
    min = getEffectiveMinFrequency();
    max = getEffectiveMaxFrequency();

//    SVDEBUG << "SpectrogramLayer::getDisplayExtents: " << min << "->" << max << endl;
    return true;
}    

bool
SpectrogramLayer::setDisplayExtents(double min, double max)
{
    if (!m_model) return false;

//    SVDEBUG << "SpectrogramLayer::setDisplayExtents: " << min << "->" << max << endl;

    if (min < 0) min = 0;
    if (max > m_model->getSampleRate()/2.0) max = m_model->getSampleRate()/2.0;
    
    int minf = int(lrint(min));
    int maxf = int(lrint(max));

    if (m_minFrequency == minf && m_maxFrequency == maxf) return true;

    invalidateImageCaches();
    invalidateMagnitudes();

    m_minFrequency = minf;
    m_maxFrequency = maxf;
    
    emit layerParametersChanged();

    int vs = getCurrentVerticalZoomStep();
    if (vs != m_lastEmittedZoomStep) {
        emit verticalZoomChanged();
        m_lastEmittedZoomStep = vs;
    }

    return true;
}

bool
SpectrogramLayer::getYScaleValue(const LayerGeometryProvider *v, int y,
                                 double &value, QString &unit) const
{
    value = getFrequencyForY(v, y);
    unit = "Hz";
    return true;
}

bool
SpectrogramLayer::snapToFeatureFrame(LayerGeometryProvider *,
                                     sv_frame_t &frame,
				     int &resolution,
				     SnapType snap) const
{
    resolution = getWindowIncrement();
    sv_frame_t left = (frame / resolution) * resolution;
    sv_frame_t right = left + resolution;

    switch (snap) {
    case SnapLeft:  frame = left;  break;
    case SnapRight: frame = right; break;
    case SnapNearest:
    case SnapNeighbouring:
	if (frame - left > right - frame) frame = right;
	else frame = left;
	break;
    }
    
    return true;
} 

void
SpectrogramLayer::measureDoubleClick(LayerGeometryProvider *v, QMouseEvent *e)
{
    const View *view = v->getView();
    ImageCache &cache = m_imageCaches[view];

    cerr << "cache width: " << cache.image.width() << ", height: "
         << cache.image.height() << endl;

    QImage image = cache.image;

    ImageRegionFinder finder;
    QRect rect = finder.findRegionExtents(&image, e->pos());
    if (rect.isValid()) {
        MeasureRect mr;
        setMeasureRectFromPixrect(v, mr, rect);
        CommandHistory::getInstance()->addCommand
            (new AddMeasurementRectCommand(this, mr));
    }
}

bool
SpectrogramLayer::getCrosshairExtents(LayerGeometryProvider *v, QPainter &paint,
                                      QPoint cursorPos,
                                      std::vector<QRect> &extents) const
{
    QRect vertical(cursorPos.x() - 12, 0, 12, v->getPaintHeight());
    extents.push_back(vertical);

    QRect horizontal(0, cursorPos.y(), cursorPos.x(), 1);
    extents.push_back(horizontal);

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

    QRect freq(sw, cursorPos.y() - paint.fontMetrics().ascent() - 2,
               paint.fontMetrics().width("123456 Hz") + 2,
               paint.fontMetrics().height());
    extents.push_back(freq);

    QRect pitch(sw, cursorPos.y() + 2,
                paint.fontMetrics().width("C#10+50c") + 2,
                paint.fontMetrics().height());
    extents.push_back(pitch);

    QRect rt(cursorPos.x(),
             v->getPaintHeight() - paint.fontMetrics().height() - 2,
             paint.fontMetrics().width("1234.567 s"),
             paint.fontMetrics().height());
    extents.push_back(rt);

    int w(paint.fontMetrics().width("1234567890") + 2);
    QRect frame(cursorPos.x() - w - 2,
                v->getPaintHeight() - paint.fontMetrics().height() - 2,
                w,
                paint.fontMetrics().height());
    extents.push_back(frame);

    return true;
}

void
SpectrogramLayer::paintCrosshairs(LayerGeometryProvider *v, QPainter &paint,
                                  QPoint cursorPos) const
{
    paint.save();

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

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

    paint.drawLine(0, cursorPos.y(), cursorPos.x() - 1, cursorPos.y());
    paint.drawLine(cursorPos.x(), 0, cursorPos.x(), v->getPaintHeight());
    
    double fundamental = getFrequencyForY(v, cursorPos.y());

    v->drawVisibleText(paint,
                       sw + 2,
                       cursorPos.y() - 2,
                       QString("%1 Hz").arg(fundamental),
                       View::OutlinedText);

    if (Pitch::isFrequencyInMidiRange(fundamental)) {
        QString pitchLabel = Pitch::getPitchLabelForFrequency(fundamental);
        v->drawVisibleText(paint,
                           sw + 2,
                           cursorPos.y() + paint.fontMetrics().ascent() + 2,
                           pitchLabel,
                           View::OutlinedText);
    }

    sv_frame_t frame = v->getFrameForX(cursorPos.x());
    RealTime rt = RealTime::frame2RealTime(frame, m_model->getSampleRate());
    QString rtLabel = QString("%1 s").arg(rt.toText(true).c_str());
    QString frameLabel = QString("%1").arg(frame);
    v->drawVisibleText(paint,
                       cursorPos.x() - paint.fontMetrics().width(frameLabel) - 2,
                       v->getPaintHeight() - 2,
                       frameLabel,
                       View::OutlinedText);
    v->drawVisibleText(paint,
                       cursorPos.x() + 2,
                       v->getPaintHeight() - 2,
                       rtLabel,
                       View::OutlinedText);

    int harmonic = 2;

    while (harmonic < 100) {

        int hy = int(lrint(getYForFrequency(v, fundamental * harmonic)));
        if (hy < 0 || hy > v->getPaintHeight()) break;
        
        int len = 7;

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

        paint.drawLine(cursorPos.x() - len,
                       hy,
                       cursorPos.x(),
                       hy);

        ++harmonic;
    }

    paint.restore();
}

QString
SpectrogramLayer::getFeatureDescription(LayerGeometryProvider *v, QPoint &pos) const
{
    int x = pos.x();
    int y = pos.y();

    if (!m_model || !m_model->isOK()) return "";

    double magMin = 0, magMax = 0;
    double phaseMin = 0, phaseMax = 0;
    double freqMin = 0, freqMax = 0;
    double adjFreqMin = 0, adjFreqMax = 0;
    QString pitchMin, pitchMax;
    RealTime rtMin, rtMax;

    bool haveValues = false;

    if (!getXBinSourceRange(v, x, rtMin, rtMax)) {
	return "";
    }
    if (getXYBinSourceRange(v, x, y, magMin, magMax, phaseMin, phaseMax)) {
	haveValues = true;
    }

    QString adjFreqText = "", adjPitchText = "";

    if (m_binDisplay == PeakFrequencies) {

	if (!getAdjustedYBinSourceRange(v, x, y, freqMin, freqMax,
					adjFreqMin, adjFreqMax)) {
	    return "";
	}

	if (adjFreqMin != adjFreqMax) {
	    adjFreqText = tr("Peak Frequency:\t%1 - %2 Hz\n")
		.arg(adjFreqMin).arg(adjFreqMax);
	} else {
	    adjFreqText = tr("Peak Frequency:\t%1 Hz\n")
		.arg(adjFreqMin);
	}

	QString pmin = Pitch::getPitchLabelForFrequency(adjFreqMin);
	QString pmax = Pitch::getPitchLabelForFrequency(adjFreqMax);

	if (pmin != pmax) {
	    adjPitchText = tr("Peak Pitch:\t%3 - %4\n").arg(pmin).arg(pmax);
	} else {
	    adjPitchText = tr("Peak Pitch:\t%2\n").arg(pmin);
	}

    } else {
	
	if (!getYBinSourceRange(v, y, freqMin, freqMax)) return "";
    }

    QString text;

    if (rtMin != rtMax) {
	text += tr("Time:\t%1 - %2\n")
	    .arg(rtMin.toText(true).c_str())
	    .arg(rtMax.toText(true).c_str());
    } else {
	text += tr("Time:\t%1\n")
	    .arg(rtMin.toText(true).c_str());
    }

    if (freqMin != freqMax) {
	text += tr("%1Bin Frequency:\t%2 - %3 Hz\n%4Bin Pitch:\t%5 - %6\n")
	    .arg(adjFreqText)
	    .arg(freqMin)
	    .arg(freqMax)
	    .arg(adjPitchText)
	    .arg(Pitch::getPitchLabelForFrequency(freqMin))
	    .arg(Pitch::getPitchLabelForFrequency(freqMax));
    } else {
	text += tr("%1Bin Frequency:\t%2 Hz\n%3Bin Pitch:\t%4\n")
	    .arg(adjFreqText)
	    .arg(freqMin)
	    .arg(adjPitchText)
	    .arg(Pitch::getPitchLabelForFrequency(freqMin));
    }	

    if (haveValues) {
	double dbMin = AudioLevel::multiplier_to_dB(magMin);
	double dbMax = AudioLevel::multiplier_to_dB(magMax);
	QString dbMinString;
	QString dbMaxString;
	if (dbMin == AudioLevel::DB_FLOOR) {
	    dbMinString = tr("-Inf");
	} else {
	    dbMinString = QString("%1").arg(lrint(dbMin));
	}
	if (dbMax == AudioLevel::DB_FLOOR) {
	    dbMaxString = tr("-Inf");
	} else {
	    dbMaxString = QString("%1").arg(lrint(dbMax));
	}
	if (lrint(dbMin) != lrint(dbMax)) {
	    text += tr("dB:\t%1 - %2").arg(dbMinString).arg(dbMaxString);
	} else {
	    text += tr("dB:\t%1").arg(dbMinString);
	}
	if (phaseMin != phaseMax) {
	    text += tr("\nPhase:\t%1 - %2").arg(phaseMin).arg(phaseMax);
	} else {
	    text += tr("\nPhase:\t%1").arg(phaseMin);
	}
    }

    return text;
}

int
SpectrogramLayer::getColourScaleWidth(QPainter &paint) const
{
    int cw;

    cw = paint.fontMetrics().width("-80dB");

    return cw;
}

int
SpectrogramLayer::getVerticalScaleWidth(LayerGeometryProvider *, bool detailed, QPainter &paint) const
{
    if (!m_model || !m_model->isOK()) return 0;

    int cw = 0;
    if (detailed) cw = getColourScaleWidth(paint);

    int tw = paint.fontMetrics().width(QString("%1")
				     .arg(m_maxFrequency > 0 ?
					  m_maxFrequency - 1 :
					  m_model->getSampleRate() / 2));

    int fw = paint.fontMetrics().width(tr("43Hz"));
    if (tw < fw) tw = fw;

    int tickw = (m_frequencyScale == LogFrequencyScale ? 10 : 4);
    
    return cw + tickw + tw + 13;
}

void
SpectrogramLayer::paintVerticalScale(LayerGeometryProvider *v, bool detailed, QPainter &paint, QRect rect) const
{
    if (!m_model || !m_model->isOK()) {
	return;
    }

    Profiler profiler("SpectrogramLayer::paintVerticalScale");

    //!!! cache this?

    int h = rect.height(), w = rect.width();

    int tickw = (m_frequencyScale == LogFrequencyScale ? 10 : 4);
    int pkw = (m_frequencyScale == LogFrequencyScale ? 10 : 0);

    int bins = m_fftSize / 2;
    sv_samplerate_t sr = m_model->getSampleRate();

    if (m_maxFrequency > 0) {
	bins = int((double(m_maxFrequency) * m_fftSize) / sr + 0.1);
	if (bins > m_fftSize / 2) bins = m_fftSize / 2;
    }

    int cw = 0;

    if (detailed) cw = getColourScaleWidth(paint);
    int cbw = paint.fontMetrics().width("dB");

    int py = -1;
    int textHeight = paint.fontMetrics().height();
    int toff = -textHeight + paint.fontMetrics().ascent() + 2;

    if (detailed && (h > textHeight * 3 + 10)) {

        int topLines = 2;
        if (m_colourScale == PhaseColourScale) topLines = 1;

	int ch = h - textHeight * (topLines + 1) - 8;
//	paint.drawRect(4, textHeight + 4, cw - 1, ch + 1);
	paint.drawRect(4 + cw - cbw, textHeight * topLines + 4, cbw - 1, ch + 1);

	QString top, bottom;
        double min = m_viewMags[v].getMin();
        double max = m_viewMags[v].getMax();

        double dBmin = AudioLevel::multiplier_to_dB(min);
        double dBmax = AudioLevel::multiplier_to_dB(max);

        if (dBmax < -60.f) dBmax = -60.f;
        else top = QString("%1").arg(lrint(dBmax));

        if (dBmin < dBmax - 60.f) dBmin = dBmax - 60.f;
        bottom = QString("%1").arg(lrint(dBmin));

        //!!! & phase etc

        if (m_colourScale != PhaseColourScale) {
            paint.drawText((cw + 6 - paint.fontMetrics().width("dBFS")) / 2,
                           2 + textHeight + toff, "dBFS");
        }

//	paint.drawText((cw + 6 - paint.fontMetrics().width(top)) / 2,
	paint.drawText(3 + cw - cbw - paint.fontMetrics().width(top),
		       2 + textHeight * topLines + toff + textHeight/2, top);

	paint.drawText(3 + cw - cbw - paint.fontMetrics().width(bottom),
		       h + toff - 3 - textHeight/2, bottom);

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

        int lasty = 0;
        int lastdb = 0;

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

            double dBval = dBmin + (((dBmax - dBmin) * i) / (ch - 1));
            int idb = int(dBval);

            double value = AudioLevel::dB_to_multiplier(dBval);
            int colour = getDisplayValue(v, value * m_gain);

	    paint.setPen(m_palette.getColour((unsigned char)colour));

            int y = textHeight * topLines + 4 + ch - i;

            paint.drawLine(5 + cw - cbw, y, cw + 2, y);

            if (i == 0) {
                lasty = y;
                lastdb = idb;
            } else if (i < ch - paint.fontMetrics().ascent() &&
                       idb != lastdb &&
                       ((abs(y - lasty) > textHeight && 
                         idb % 10 == 0) ||
                        (abs(y - lasty) > paint.fontMetrics().ascent() && 
                         idb % 5 == 0))) {
                paint.setPen(v->getBackground());
                QString text = QString("%1").arg(idb);
                paint.drawText(3 + cw - cbw - paint.fontMetrics().width(text),
                               y + toff + textHeight/2, text);
                paint.setPen(v->getForeground());
                paint.drawLine(5 + cw - cbw, y, 8 + cw - cbw, y);
                lasty = y;
                lastdb = idb;
            }
	}
	paint.restore();
    }

    paint.drawLine(cw + 7, 0, cw + 7, h);

    int bin = -1;

    for (int y = 0; y < v->getPaintHeight(); ++y) {

	double q0, q1;
	if (!getYBinRange(v, v->getPaintHeight() - y, q0, q1)) continue;

	int vy;

	if (int(q0) > bin) {
	    vy = y;
	    bin = int(q0);
	} else {
	    continue;
	}

	int freq = int((sr * bin) / m_fftSize);

	if (py >= 0 && (vy - py) < textHeight - 1) {
	    if (m_frequencyScale == LinearFrequencyScale) {
		paint.drawLine(w - tickw, h - vy, w, h - vy);
	    }
	    continue;
	}

	QString text = QString("%1").arg(freq);
	if (bin == 1) text = tr("%1Hz").arg(freq); // bin 0 is DC
	paint.drawLine(cw + 7, h - vy, w - pkw - 1, h - vy);

	if (h - vy - textHeight >= -2) {
	    int tx = w - 3 - paint.fontMetrics().width(text) - std::max(tickw, pkw);
	    paint.drawText(tx, h - vy + toff, text);
	}

	py = vy;
    }

    if (m_frequencyScale == LogFrequencyScale) {

        // piano keyboard

        PianoScale().paintPianoVertical
            (v, paint, QRect(w - pkw - 1, 0, pkw, h),
             getEffectiveMinFrequency(), getEffectiveMaxFrequency());
    }

    m_haveDetailedScale = detailed;
}

class SpectrogramRangeMapper : public RangeMapper
{
public:
    SpectrogramRangeMapper(sv_samplerate_t sr, int /* fftsize */) :
        m_dist(sr / 2),
        m_s2(sqrt(sqrt(2))) { }
    ~SpectrogramRangeMapper() { }
    
    virtual int getPositionForValue(double value) const {

        double dist = m_dist;
    
        int n = 0;

        while (dist > (value + 0.00001) && dist > 0.1) {
            dist /= m_s2;
            ++n;
        }

        return n;
    }
    
    virtual int getPositionForValueUnclamped(double value) const {
        // We don't really support this
        return getPositionForValue(value);
    }

    virtual double getValueForPosition(int position) const {

        // Vertical zoom step 0 shows the entire range from DC ->
        // Nyquist frequency.  Step 1 shows 2^(1/4) of the range of
        // step 0, and so on until the visible range is smaller than
        // the frequency step between bins at the current fft size.

        double dist = m_dist;
    
        int n = 0;
        while (n < position) {
            dist /= m_s2;
            ++n;
        }

        return dist;
    }
    
    virtual double getValueForPositionUnclamped(int position) const {
        // We don't really support this
        return getValueForPosition(position);
    }

    virtual QString getUnit() const { return "Hz"; }

protected:
    double m_dist;
    double m_s2;
};

int
SpectrogramLayer::getVerticalZoomSteps(int &defaultStep) const
{
    if (!m_model) return 0;

    sv_samplerate_t sr = m_model->getSampleRate();

    SpectrogramRangeMapper mapper(sr, m_fftSize);

//    int maxStep = mapper.getPositionForValue((double(sr) / m_fftSize) + 0.001);
    int maxStep = mapper.getPositionForValue(0);
    int minStep = mapper.getPositionForValue(double(sr) / 2);

    int initialMax = m_initialMaxFrequency;
    if (initialMax == 0) initialMax = int(sr / 2);

    defaultStep = mapper.getPositionForValue(initialMax) - minStep;

//    SVDEBUG << "SpectrogramLayer::getVerticalZoomSteps: " << maxStep - minStep << " (" << maxStep <<"-" << minStep << "), default is " << defaultStep << " (from initial max freq " << initialMax << ")" << endl;

    return maxStep - minStep;
}

int
SpectrogramLayer::getCurrentVerticalZoomStep() const
{
    if (!m_model) return 0;

    double dmin, dmax;
    getDisplayExtents(dmin, dmax);
    
    SpectrogramRangeMapper mapper(m_model->getSampleRate(), m_fftSize);
    int n = mapper.getPositionForValue(dmax - dmin);
//    SVDEBUG << "SpectrogramLayer::getCurrentVerticalZoomStep: " << n << endl;
    return n;
}

void
SpectrogramLayer::setVerticalZoomStep(int step)
{
    if (!m_model) return;

    double dmin = m_minFrequency, dmax = m_maxFrequency;
//    getDisplayExtents(dmin, dmax);

//    cerr << "current range " << dmin << " -> " << dmax << ", range " << dmax-dmin << ", mid " << (dmax + dmin)/2 << endl;
    
    sv_samplerate_t sr = m_model->getSampleRate();
    SpectrogramRangeMapper mapper(sr, m_fftSize);
    double newdist = mapper.getValueForPosition(step);

    double newmin, newmax;

    if (m_frequencyScale == LogFrequencyScale) {

        // need to pick newmin and newmax such that
        //
        // (log(newmin) + log(newmax)) / 2 == logmid
        // and
        // newmax - newmin = newdist
        //
        // so log(newmax - newdist) + log(newmax) == 2logmid
        // log(newmax(newmax - newdist)) == 2logmid
        // newmax.newmax - newmax.newdist == exp(2logmid)
        // newmax^2 + (-newdist)newmax + -exp(2logmid) == 0
        // quadratic with a = 1, b = -newdist, c = -exp(2logmid), all known
        // 
        // positive root
        // newmax = (newdist + sqrt(newdist^2 + 4exp(2logmid))) / 2
        //
        // but logmid = (log(dmin) + log(dmax)) / 2
        // so exp(2logmid) = exp(log(dmin) + log(dmax))
        // = exp(log(dmin.dmax))
        // = dmin.dmax
        // so newmax = (newdist + sqrtf(newdist^2 + 4dmin.dmax)) / 2

        newmax = (newdist + sqrt(newdist*newdist + 4*dmin*dmax)) / 2;
        newmin = newmax - newdist;

//        cerr << "newmin = " << newmin << ", newmax = " << newmax << endl;

    } else {
        double dmid = (dmax + dmin) / 2;
        newmin = dmid - newdist / 2;
        newmax = dmid + newdist / 2;
    }

    double mmin, mmax;
    mmin = 0;
    mmax = double(sr) / 2;
    
    if (newmin < mmin) {
        newmax += (mmin - newmin);
        newmin = mmin;
    }
    if (newmax > mmax) {
        newmax = mmax;
    }
    
//    SVDEBUG << "SpectrogramLayer::setVerticalZoomStep: " << step << ": " << newmin << " -> " << newmax << " (range " << newdist << ")" << endl;

    setMinFrequency(int(lrint(newmin)));
    setMaxFrequency(int(lrint(newmax)));
}

RangeMapper *
SpectrogramLayer::getNewVerticalZoomRangeMapper() const
{
    if (!m_model) return 0;
    return new SpectrogramRangeMapper(m_model->getSampleRate(), m_fftSize);
}

void
SpectrogramLayer::updateMeasureRectYCoords(LayerGeometryProvider *v, const MeasureRect &r) const
{
    int y0 = 0;
    if (r.startY > 0.0) y0 = int(getYForFrequency(v, r.startY));
    
    int y1 = y0;
    if (r.endY > 0.0) y1 = int(getYForFrequency(v, r.endY));

//    SVDEBUG << "SpectrogramLayer::updateMeasureRectYCoords: start " << r.startY << " -> " << y0 << ", end " << r.endY << " -> " << y1 << endl;

    r.pixrect = QRect(r.pixrect.x(), y0, r.pixrect.width(), y1 - y0);
}

void
SpectrogramLayer::setMeasureRectYCoord(LayerGeometryProvider *v, MeasureRect &r, bool start, int y) const
{
    if (start) {
        r.startY = getFrequencyForY(v, y);
        r.endY = r.startY;
    } else {
        r.endY = getFrequencyForY(v, y);
    }
//    SVDEBUG << "SpectrogramLayer::setMeasureRectYCoord: start " << r.startY << " <- " << y << ", end " << r.endY << " <- " << y << endl;

}

void
SpectrogramLayer::toXml(QTextStream &stream,
                        QString indent, QString extraAttributes) const
{
    QString s;
    
    s += QString("channel=\"%1\" "
		 "windowSize=\"%2\" "
		 "windowHopLevel=\"%3\" "
		 "gain=\"%4\" "
		 "threshold=\"%5\" ")
	.arg(m_channel)
	.arg(m_windowSize)
	.arg(m_windowHopLevel)
	.arg(m_gain)
	.arg(m_threshold);

    s += QString("minFrequency=\"%1\" "
		 "maxFrequency=\"%2\" "
		 "colourScale=\"%3\" "
		 "colourScheme=\"%4\" "
		 "colourRotation=\"%5\" "
		 "frequencyScale=\"%6\" "
		 "binDisplay=\"%7\" ")
	.arg(m_minFrequency)
	.arg(m_maxFrequency)
	.arg(m_colourScale)
	.arg(m_colourMap)
	.arg(m_colourRotation)
	.arg(m_frequencyScale)
	.arg(m_binDisplay);

    s += QString("normalizeColumns=\"%1\" "
                 "normalizeVisibleArea=\"%2\" "
                 "normalizeHybrid=\"%3\" ")
	.arg(m_normalization == NormalizeColumns ? "true" : "false")
        .arg(m_normalization == NormalizeVisibleArea ? "true" : "false")
        .arg(m_normalization == NormalizeHybrid ? "true" : "false");

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

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

    int channel = attributes.value("channel").toInt(&ok);
    if (ok) setChannel(channel);

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

    int windowHopLevel = attributes.value("windowHopLevel").toUInt(&ok);
    if (ok) setWindowHopLevel(windowHopLevel);
    else {
        int windowOverlap = attributes.value("windowOverlap").toUInt(&ok);
        // a percentage value
        if (ok) {
            if (windowOverlap == 0) setWindowHopLevel(0);
            else if (windowOverlap == 25) setWindowHopLevel(1);
            else if (windowOverlap == 50) setWindowHopLevel(2);
            else if (windowOverlap == 75) setWindowHopLevel(3);
            else if (windowOverlap == 90) setWindowHopLevel(4);
        }
    }

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

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

    int minFrequency = attributes.value("minFrequency").toUInt(&ok);
    if (ok) {
        SVDEBUG << "SpectrogramLayer::setProperties: setting min freq to " << minFrequency << endl;
        setMinFrequency(minFrequency);
    }

    int maxFrequency = attributes.value("maxFrequency").toUInt(&ok);
    if (ok) {
        SVDEBUG << "SpectrogramLayer::setProperties: setting max freq to " << maxFrequency << endl;
        setMaxFrequency(maxFrequency);
    }

    ColourScale colourScale = (ColourScale)
	attributes.value("colourScale").toInt(&ok);
    if (ok) setColourScale(colourScale);

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

    int colourRotation = attributes.value("colourRotation").toInt(&ok);
    if (ok) setColourRotation(colourRotation);

    FrequencyScale frequencyScale = (FrequencyScale)
	attributes.value("frequencyScale").toInt(&ok);
    if (ok) setFrequencyScale(frequencyScale);

    BinDisplay binDisplay = (BinDisplay)
	attributes.value("binDisplay").toInt(&ok);
    if (ok) setBinDisplay(binDisplay);

    bool normalizeColumns =
	(attributes.value("normalizeColumns").trimmed() == "true");
    if (normalizeColumns) {
        setNormalization(NormalizeColumns);
    }

    bool normalizeVisibleArea =
	(attributes.value("normalizeVisibleArea").trimmed() == "true");
    if (normalizeVisibleArea) {
        setNormalization(NormalizeVisibleArea);
    }

    bool normalizeHybrid =
	(attributes.value("normalizeHybrid").trimmed() == "true");
    if (normalizeHybrid) {
        setNormalization(NormalizeHybrid);
    }
}