view widgets/LevelPanWidget.cpp @ 1534:bfd8b22fd67c

Fix #1904 Scrolling colour 3d plot does not always work when in View normalisation mode. We shouldn't imagine we've just invalidated the cache if the truth is that we've only just created the renderer

/* -*- 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 "WidgetScale.h"

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

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

/**
 * Gain and pan scales:
 *
 * Gain: we have 5 circles vertically in the display, each of which
 * has half-circle and full-circle versions, and we also have "no
 * circles", so there are in total 11 distinct levels, which we refer
 * to as "notches" and number 0-10. (We use "notch" because "level" is
 * used by the external API to refer to audio gain.)
 * 
 * i.e. the levels are represented by these (schematic, rotated to
 * horizontal) displays:
 *
 *  0  X
 *  1  [
 *  2  []
 *  3  [][
 *  ...
 *  9  [][][][][
 *  10 [][][][][]
 * 
 * If we have mute enabled, then we map the range 0-10 to gain using
 * AudioLevel::fader_to_* with the ShortFader type, which treats fader
 * 0 as muted. If mute is disabled, then we map the range 1-10.
 * 
 * We can also disable half-circles, which leaves the range unchanged
 * but limits the notches to even values.
 * 
 * Pan: we have 5 columns with no finer resolution, so we only have 2
 * possible pan values on each side of centre.
 */

static const int maxPan = 2; // range is -maxPan to maxPan

LevelPanWidget::LevelPanWidget(QWidget *parent) :
    QWidget(parent),
    m_minNotch(0),
    m_maxNotch(10),
    m_notch(m_maxNotch),
    m_pan(0),
    m_monitorLeft(-1),
    m_monitorRight(-1),
    m_editable(true),
    m_editing(false),
    m_includeMute(true),
    m_includeHalfSteps(true)
{
    setToolTip(tr("Drag vertically to adjust level, horizontally to adjust pan"));
    setLevel(1.0);
    setPan(0.0);
}

LevelPanWidget::~LevelPanWidget()
{
}

void
LevelPanWidget::setToDefault()
{
    setLevel(1.0);
    setPan(0.0);
    emitLevelChanged();
    emitPanChanged();
}

QSize
LevelPanWidget::sizeHint() const
{
    return WidgetScale::scaleQSize(QSize(40, 40));
}

int
LevelPanWidget::clampNotch(int notch) const
{
    if (notch < m_minNotch) notch = m_minNotch;
    if (notch > m_maxNotch) notch = m_maxNotch;
    if (!m_includeHalfSteps) {
        notch = (notch / 2) * 2;
    }
    return notch;
}

int
LevelPanWidget::clampPan(int pan) const
{
    if (pan < -maxPan) pan = -maxPan;
    if (pan > maxPan) pan = maxPan;
    return pan;
}

int
LevelPanWidget::audioLevelToNotch(float audioLevel) const
{
    int notch = AudioLevel::multiplier_to_fader
        (audioLevel, m_maxNotch, AudioLevel::ShortFader);
    return clampNotch(notch);
}

float
LevelPanWidget::notchToAudioLevel(int notch) const
{
    return float(AudioLevel::fader_to_multiplier
                 (notch, m_maxNotch, AudioLevel::ShortFader));
}

void
LevelPanWidget::setLevel(float level)
{
    int notch = audioLevelToNotch(level);
    if (notch != m_notch) {
        m_notch = notch;
        float convertsTo = getLevel();
        if (fabsf(convertsTo - level) > 1e-5) {
            emitLevelChanged();
        }
        update();
    }
}

float
LevelPanWidget::getLevel() const
{
    return notchToAudioLevel(m_notch);
}

int
LevelPanWidget::audioPanToPan(float audioPan) const
{
    int pan = int(round(audioPan * maxPan));
    pan = clampPan(pan);
    return pan;
}

float
LevelPanWidget::panToAudioPan(int pan) const
{
    return float(pan) / float(maxPan);
}

void
LevelPanWidget::setPan(float fpan)
{
    int pan = audioPanToPan(fpan);
    if (pan != m_pan) {
        m_pan = pan;
        update();
    }
}

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

void
LevelPanWidget::setMonitoringLevels(float left, float right)
{
    m_monitorLeft = left;
    m_monitorRight = right;
    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;
    if (m_includeMute) {
        m_minNotch = 0;
    } else {
        m_minNotch = 1;
    }
    emitLevelChanged();
    update();
}

void
LevelPanWidget::emitLevelChanged()
{
    emit levelChanged(getLevel());
}

void
LevelPanWidget::emitPanChanged()
{
    emit panChanged(getPan());
}

void
LevelPanWidget::mousePressEvent(QMouseEvent *e)
{
    if (e->button() == Qt::MidButton ||
        ((e->button() == Qt::LeftButton) &&
         (e->modifiers() & Qt::ControlModifier))) {
        setToDefault();
    } else if (e->button() == Qt::LeftButton) {
        m_editing = true;
        mouseMoveEvent(e);
    }
}

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

void
LevelPanWidget::mouseMoveEvent(QMouseEvent *e)
{
    if (!m_editable) return;
    if (!m_editing) return;
    
    int notch = coordsToNotch(rect(), e->pos());
    int pan = coordsToPan(rect(), e->pos());

    if (notch == m_notch && pan == m_pan) {
        return;
    }
    if (notch != m_notch) {
        m_notch = notch;
        emitLevelChanged();
    }
    if (pan != m_pan) {
        m_pan = pan;
        emitPanChanged();
    }
    update();
}

void
LevelPanWidget::wheelEvent(QWheelEvent *e)
{
    int delta = m_wheelCounter.count(e);

    if (delta == 0) {
        return;
    }

    if (e->modifiers() & Qt::ControlModifier) {
        m_pan = clampPan(m_pan + delta);
        emitPanChanged();
        update();
    } else {
        m_notch = clampNotch(m_notch + delta);
        emitLevelChanged();
        update();
    }
}

int
LevelPanWidget::coordsToNotch(QRectF rect, QPointF loc) const
{
    double h = rect.height();

    int nnotch = m_maxNotch + 1;
    double cell = h / nnotch;

    int notch = int((h - (loc.y() - rect.y())) / cell);
    notch = clampNotch(notch);

    return notch;
}    

int
LevelPanWidget::coordsToPan(QRectF rect, QPointF loc) const
{
    double w = rect.width();

    int npan = maxPan * 2 + 1;
    double cell = w / npan;

    int pan = int((loc.x() - rect.x()) / cell) - maxPan;
    pan = clampPan(pan);

    return pan;
}

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

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

QSizeF
LevelPanWidget::cellLightSize(QRectF rect) const
{
    double extent = 0.7;
    QSizeF cs = cellSize(rect);
    double m = std::min(cs.width(), cs.height());
    return QSizeF(m * extent, m * extent);
}

QRectF
LevelPanWidget::cellLightRect(QRectF rect, int row, int col) const
{
    QSizeF cls = cellLightSize(rect);
    QPointF cc = cellCentre(rect, row, col);
    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() / (m_maxNotch/2 * 10.));
    return std::min(th, tw);
}

double
LevelPanWidget::cornerRadius(QRectF rect) const
{
    QSizeF cs = cellSize(rect);
    double m = std::min(cs.width(), cs.height());
    return m / 5;
}

QRectF
LevelPanWidget::cellOutlineRect(QRectF rect, int row, int col) const
{
    QRectF clr = cellLightRect(rect, row, col);
    double adj = thinLineWidth(rect)/2 + 0.5;
    return clr.adjusted(-adj, -adj, adj, adj);
}

QColor
LevelPanWidget::cellToColour(int cell) const
{
    if (cell < 1) return Qt::black;
    if (cell < 2) return QColor(80, 0, 0);
    if (cell < 3) return QColor(160, 0, 0);
    if (cell < 4) return QColor(255, 0, 0);
    return QColor(255, 255, 0);
}

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

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

    double thin = thinLineWidth(rect);
    double radius = cornerRadius(rect);

    QColor columnBackground = QColor(180, 180, 180);

    bool monitoring = (m_monitorLeft > 0.f || m_monitorRight > 0.f);
    
    QPen pen;
    if (isEnabled()) {
        pen.setColor(Qt::black);
    } else {
        pen.setColor(Qt::darkGray);
    }
    pen.setWidthF(thin);
    pen.setCapStyle(Qt::FlatCap);
    pen.setJoinStyle(Qt::MiterJoin);

    for (int pan = -maxPan; pan <= maxPan; ++pan) {

        paint.setPen(Qt::NoPen);
        paint.setBrush(columnBackground);
        
        QRectF top = cellOutlineRect(rect, m_maxNotch/2 - 1, pan);
        QRectF bottom = cellOutlineRect(rect, 0, pan);
        paint.drawRoundedRect(QRectF(top.x(),
                                     top.y(),
                                     top.width(),
                                     bottom.y() + bottom.height() - top.y()),
                              radius, radius);

        if (!asIfEditable && m_includeMute && m_notch == 0) {
            // We will instead be drawing a single big X for mute,
            // after this loop
            continue;
        }

        if (!monitoring && m_pan != pan) {
            continue;
        }

        int monitorNotch = 0;
        if (monitoring) {
            float rprop = float(pan - (-maxPan)) / float(maxPan * 2);
            float lprop = float(maxPan - pan) / float(maxPan * 2);
            float monitorLevel =
                lprop * m_monitorLeft * m_monitorLeft +
                rprop * m_monitorRight * m_monitorRight;
            monitorNotch = audioLevelToNotch(monitorLevel);
        }

        int firstCell = 0;
        int lastCell = m_maxNotch / 2 - 1;
        
        for (int cell = firstCell; cell <= lastCell; ++cell) {

            QRectF clr = cellLightRect(rect, cell, pan);

            if (m_includeMute && m_pan == pan && m_notch == 0) {
                // X for mute in the bottom cell
                paint.setPen(pen);
                paint.drawLine(clr.topLeft(), clr.bottomRight());
                paint.drawLine(clr.bottomLeft(), clr.topRight());
                break;
            }

            const int none = 0, half = 1, full = 2;

            int fill = none;

            int outline = none;
            if (m_pan == pan && m_notch > cell * 2 + 1) {
                outline = full;
            } else if (m_pan == pan && m_notch == cell * 2 + 1) {
                outline = half;
            }

            if (monitoring) {
                if (monitorNotch > cell * 2 + 1) {
                    fill = full;
                } else if (monitorNotch == cell * 2 + 1) {
                    fill = half;
                }
            } else {
                if (isEnabled()) {
                    fill = outline;
                }
            }                

            // If one of {fill, outline} is "full" and the other is
            // "half", then we draw the "half" one first (because we
            // need to erase half of it)

            if (fill == half || outline == half) {
                if (fill == half) {
                    paint.setBrush(cellToColour(cell));
                } else {
                    paint.setBrush(Qt::NoBrush);
                }
                if (outline == half) {
                    paint.setPen(pen);
                } else {
                    paint.setPen(Qt::NoPen);
                }

                paint.drawRoundedRect(clr, radius, radius);

                paint.setBrush(columnBackground);
                
                if (cell == lastCell) {
                    QPen bgpen(pen);
                    bgpen.setColor(columnBackground);
                    paint.setPen(bgpen);
                    paint.drawRoundedRect(QRectF(clr.x(),
                                                 clr.y(),
                                                 clr.width(),
                                                 clr.height()/4),
                                          radius, radius);
                    paint.drawRect(QRectF(clr.x(),
                                          clr.y() + clr.height()/4,
                                          clr.width(),
                                          clr.height()/4));
                } else {
                    paint.setPen(Qt::NoPen);
                    QRectF cor = cellOutlineRect(rect, cell, pan);
                    paint.drawRect(QRectF(cor.x(),
                                          cor.y() - 0.5,
                                          cor.width(),
                                          cor.height()/2));
                }
            }

            if (outline == full || fill == full) {

                if (fill == full) {
                    paint.setBrush(cellToColour(cell));
                } else {
                    paint.setBrush(Qt::NoBrush);
                }
                if (outline == full) {
                    paint.setPen(pen);
                } else {
                    paint.setPen(Qt::NoPen);
                }
                
                paint.drawRoundedRect(clr, radius, radius);
            }
        }
    }

    if (!asIfEditable && m_includeMute && m_notch == 0) {
        // The X for mute takes up the whole display when we're not
        // being rendered in editable style
        pen.setColor(Qt::black);
        pen.setWidthF(thin * 2);
        pen.setCapStyle(Qt::RoundCap);
        paint.setPen(pen);
        paint.drawLine(cellCentre(rect, 0, -maxPan),
                       cellCentre(rect, m_maxNotch/2 - 1, maxPan));
        paint.drawLine(cellCentre(rect, m_maxNotch/2 - 1, -maxPan),
                       cellCentre(rect, 0, maxPan));
    }
}

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

void
LevelPanWidget::enterEvent(QEvent *e)
{
    QWidget::enterEvent(e);
    emit mouseEntered();
}

void
LevelPanWidget::leaveEvent(QEvent *e)
{
    QWidget::enterEvent(e);
    emit mouseLeft();
}