view widgets/LevelPanWidget.cpp @ 1127:9fb8dfd7ce4c spectrogram-minor-refactor

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

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

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

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    
    This 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 "LevelPanWidget.h"

#include <QPainter>
#include <QMouseEvent>
#include <QWheelEvent>

#include "layer/ColourMapper.h"
#include "base/AudioLevel.h"

#include <iostream>
#include <cmath>
#include <cassert>

using std::cerr;
using std::endl;

static const int maxLevel = 4; // min is 0, may be mute or not depending on m_includeMute
static const int maxPan = 2; // range is -maxPan to maxPan

LevelPanWidget::LevelPanWidget(QWidget *parent) :
    QWidget(parent),
    m_level(maxLevel),
    m_pan(0),
    m_editable(true),
    m_includeMute(true)
{
}

LevelPanWidget::~LevelPanWidget()
{
}

QSize
LevelPanWidget::sizeHint() const
{
    static double ratio = 0.0;
    if (ratio == 0.0) {
        double baseEm;
#ifdef Q_OS_MAC
        baseEm = 17.0;
#else
        baseEm = 15.0;
#endif
        double em = QFontMetrics(QFont()).height();
        ratio = em / baseEm;
    }

    int pixels = 40;
    int scaled = int(pixels * ratio + 0.5);
    if (pixels != 0 && scaled == 0) scaled = 1;
    return QSize(scaled, scaled);
}

static int
db_to_level(double db)
{
    // Only if !m_includeMute, otherwise AudioLevel is used.
    // Levels are: +6 0 -6 -12 -20
    assert(maxLevel == 4);
    if (db > 3.) return 4;
    else if (db > -3.) return 3;
    else if (db > -9.) return 2;
    else if (db > -16.) return 1;
    else return 0;
}

static double
level_to_db(int level)
{
    // Only if !m_includeMute, otherwise AudioLevel is used.
    // Levels are: +6 0 -6 -12 -20
    assert(maxLevel == 4);
    if (level >= 4) return 6.;
    else if (level == 3) return 0.;
    else if (level == 2) return -6.;
    else if (level == 1) return -12.;
    else return -20.;
}

void
LevelPanWidget::setLevel(float flevel)
{
    int level;
    if (m_includeMute) {
        level = AudioLevel::multiplier_to_fader
            (flevel, maxLevel, AudioLevel::ShortFader);
    } else {
        level = db_to_level(AudioLevel::multiplier_to_dB(flevel));
    }
    if (level < 0) level = 0;
    if (level > maxLevel) level = maxLevel;
    if (level != m_level) {
	m_level = level;
	float convertsTo = getLevel();
	if (fabsf(convertsTo - flevel) > 1e-5) {
	    emitLevelChanged();
	}
	update();
    }
}

float
LevelPanWidget::getLevel() const
{
    if (m_includeMute) {
        return float(AudioLevel::fader_to_multiplier
                     (m_level, maxLevel, AudioLevel::ShortFader));
    } else {
        return float(AudioLevel::dB_to_multiplier(level_to_db(m_level)));
    }
}

void
LevelPanWidget::setPan(float pan)
{
    m_pan = int(round(pan * maxPan));
    if (m_pan < -maxPan) m_pan = -maxPan;
    if (m_pan > maxPan) m_pan = maxPan;
    update();
}

bool
LevelPanWidget::isEditable() const
{
    return m_editable;
}

bool
LevelPanWidget::includesMute() const
{
    return m_includeMute;
}

void
LevelPanWidget::setEditable(bool editable)
{
    m_editable = editable;
    update();
}

void
LevelPanWidget::setIncludeMute(bool include)
{
    m_includeMute = include;
    emitLevelChanged();
    update();
}

float
LevelPanWidget::getPan() const
{
    return float(m_pan) / float(maxPan);
}

void
LevelPanWidget::emitLevelChanged()
{
    cerr << "emitting levelChanged(" << getLevel() << ")" << endl;
    emit levelChanged(getLevel());
}

void
LevelPanWidget::emitPanChanged()
{
    cerr << "emitting panChanged(" << getPan() << ")" << endl;
    emit panChanged(getPan());
}

void
LevelPanWidget::mousePressEvent(QMouseEvent *e)
{
    mouseMoveEvent(e);
}

void
LevelPanWidget::mouseMoveEvent(QMouseEvent *e)
{
    if (!m_editable) return;
    
    int level, pan;
    toCell(rect(), e->pos(), level, pan);
    if (level == m_level && pan == m_pan) {
	return;
    }
    if (level != m_level) {
	m_level = level;
	emitLevelChanged();
    }
    if (pan != m_pan) {
	m_pan = pan;
	emitPanChanged();
    }
    update();
}

void
LevelPanWidget::mouseReleaseEvent(QMouseEvent *e)
{
    mouseMoveEvent(e);
}

void
LevelPanWidget::wheelEvent(QWheelEvent *e)
{
    if (e->modifiers() & Qt::ControlModifier) {
	if (e->delta() > 0) {
	    if (m_pan < maxPan) {
		++m_pan;
		emitPanChanged();
		update();
	    }
	} else {
	    if (m_pan > -maxPan) {
		--m_pan;
		emitPanChanged();
		update();
	    }
	}
    } else {
	if (e->delta() > 0) {
	    if (m_level < maxLevel) {
		++m_level;
		emitLevelChanged();
		update();
	    }
	} else {
	    if (m_level > 0) {
		--m_level;
		emitLevelChanged();
		update();
	    }
	}
    }
}

void
LevelPanWidget::toCell(QRectF rect, QPointF loc, int &level, int &pan) const
{
    double w = rect.width(), h = rect.height();

    int npan = maxPan * 2 + 1;
    int nlevel = maxLevel + 1;

    double wcell = w / npan, hcell = h / nlevel;

    level = int((h - (loc.y() - rect.y())) / hcell);
    if (level < 0) level = 0;
    if (level > maxLevel) level = maxLevel;

    pan = int((loc.x() - rect.x()) / wcell) - maxPan;
    if (pan < -maxPan) pan = -maxPan;
    if (pan > maxPan) pan = maxPan;
}

QSizeF
LevelPanWidget::cellSize(QRectF rect) const
{
    double w = rect.width(), h = rect.height();
    int npan = maxPan * 2 + 1;
    int nlevel = maxLevel + 1;
    double wcell = w / npan, hcell = h / nlevel;
    return QSizeF(wcell, hcell);
}

QPointF
LevelPanWidget::cellCentre(QRectF rect, int level, int pan) const
{
    QSizeF cs = cellSize(rect);
    return QPointF(rect.x() + cs.width() * (pan + maxPan) + cs.width() / 2.,
		   rect.y() + rect.height() - cs.height() * (level + 1) + cs.height() / 2.);
}

QSizeF
LevelPanWidget::cellLightSize(QRectF rect) const
{
    double extent = 3. / 4.;
    QSizeF cs = cellSize(rect);
    double m = std::min(cs.width(), cs.height());
    return QSizeF(m * extent, m * extent);
}

QRectF
LevelPanWidget::cellLightRect(QRectF rect, int level, int pan) const
{
    QSizeF cls = cellLightSize(rect);
    QPointF cc = cellCentre(rect, level, pan);
    return QRectF(cc.x() - cls.width() / 2., 
		  cc.y() - cls.height() / 2.,
		  cls.width(),
		  cls.height());
}

double
LevelPanWidget::thinLineWidth(QRectF rect) const
{
    double tw = ceil(rect.width() / (maxPan * 2. * 10.));
    double th = ceil(rect.height() / (maxLevel * 10.));
    return std::min(th, tw);
}

static QColor
level_to_colour(int level)
{
    assert(maxLevel == 4);
    if (level == 0) return Qt::black;
    else if (level == 1) return QColor(80, 0, 0);
    else if (level == 2) return QColor(160, 0, 0);
    else if (level == 3) return QColor(255, 0, 0);
    else return QColor(255, 255, 0);
}

void
LevelPanWidget::renderTo(QPaintDevice *dev, QRectF rect, bool asIfEditable) const
{
    QPainter paint(dev);

    paint.setRenderHint(QPainter::Antialiasing, true);

    QPen pen;

    double thin = thinLineWidth(rect);

    pen.setColor(QColor(127, 127, 127, 127));
    pen.setWidthF(cellLightSize(rect).width() + thin);
    pen.setCapStyle(Qt::RoundCap);
    paint.setPen(pen);

    for (int pan = -maxPan; pan <= maxPan; ++pan) {
	paint.drawLine(cellCentre(rect, 0, pan), cellCentre(rect, maxLevel, pan));
    }

    if (isEnabled()) {
	pen.setColor(Qt::black);
    } else {
	pen.setColor(Qt::darkGray);
    }

    if (!asIfEditable && m_includeMute && m_level == 0) {
        pen.setWidthF(thin * 2);
        pen.setCapStyle(Qt::RoundCap);
        paint.setPen(pen);
        paint.drawLine(cellCentre(rect, 0, -maxPan),
                       cellCentre(rect, maxLevel, maxPan));
        paint.drawLine(cellCentre(rect, maxLevel, -maxPan),
                       cellCentre(rect, 0, maxPan));
        return;
    }
    
    pen.setWidthF(thin);
    pen.setCapStyle(Qt::FlatCap);
    paint.setPen(pen);
    
    for (int level = 0; level <= m_level; ++level) {
	if (isEnabled()) {
	    paint.setBrush(level_to_colour(level));
	}
	QRectF clr = cellLightRect(rect, level, m_pan);
	if (m_includeMute && m_level == 0) {
	    paint.drawLine(clr.topLeft(), clr.bottomRight());
	    paint.drawLine(clr.bottomLeft(), clr.topRight());
	} else {
	    paint.drawEllipse(clr);
	}
    }
}

void
LevelPanWidget::paintEvent(QPaintEvent *)
{
    renderTo(this, rect(), m_editable);
}