PrimaryFlightDisplay.cpp

#include "PrimaryFlightDisplay.h"
#include "UASManager.h"

//#include "ui_primaryflightdisplay.h"
#include <QDebug>
#include <QRectF>
#include <cmath>
#include <QPen>
#include <QPainter>
#include <QPainterPath>
#include <QResizeEvent>
#include <QtCore/qmath.h>
//#include <cmath>

/*
 *@TODO:
 * global fixed pens (and painters too?)
 * repaint on demand multiple canvases
 * multi implementation with shared model class
 */
double PrimaryFlightDisplay_round(double value, int digits=0)
{
    return floor(value * pow(10, digits) + 0.5) / pow(10, digits);
}

const int PrimaryFlightDisplay::tickValues[] = {10, 20, 30, 45, 60};
const QString PrimaryFlightDisplay::compassWindNames[] = {
    QString("N"),
    QString("NE"),
    QString("E"),
    QString("SE"),
    QString("S"),
    QString("SW"),
    QString("W"),
    QString("NW")
};

PrimaryFlightDisplay::PrimaryFlightDisplay(int width, int height, QWidget *parent) :
    QWidget(parent),

    uas(NULL),

    altimeterMode(GPS_MAIN),
    altimeterFrame(ASL),
    speedMode(GROUND_MAIN),

    roll(UNKNOWN_ATTITUDE),
    pitch(UNKNOWN_ATTITUDE),
    //    heading(NAN),
    heading(UNKNOWN_ATTITUDE),
    primaryAltitude(UNKNOWN_ALTITUDE),
    GPSAltitude(UNKNOWN_ALTITUDE),
    aboveHomeAltitude(UNKNOWN_ALTITUDE),
    primarySpeed(UNKNOWN_SPEED),
    groundspeed(UNKNOWN_SPEED),
    verticalVelocity(UNKNOWN_ALTITUDE),

    font("Bitstream Vera Sans"),
    refreshTimer(new QTimer(this)),

    navigationCrosstrackError(0),
    navigationTargetBearing(UNKNOWN_ATTITUDE),

    layout(COMPASS_INTEGRATED),
    style(OVERLAY_HSI),

    redColor(QColor::fromHsvF(0, 0.75, 0.9)),
    amberColor(QColor::fromHsvF(0.12, 0.6, 1.0)),
    greenColor(QColor::fromHsvF(0.25, 0.8, 0.8)),

    lineWidth(2),
    fineLineWidth(1),

    instrumentEdgePen(QColor::fromHsvF(0, 0, 0.65, 0.5)),
    //    AIEdgePen(QColor::fromHsvF(0, 0, 0.65, 0.5)),

    instrumentBackground(QColor::fromHsvF(0, 0, 0.3, 0.3)),
    instrumentOpagueBackground(QColor::fromHsvF(0, 0, 0.3, 1.0))
{
    setMinimumSize(120, 80);
    setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

    // Connect with UAS
    connect(UASManager::instance(), SIGNAL(activeUASSet(UASInterface*)), this, SLOT(setActiveUAS(UASInterface*)));
    if (UASManager::instance()->getActiveUAS() != NULL) setActiveUAS(UASManager::instance()->getActiveUAS());

    // Refresh timer
    refreshTimer->setInterval(updateInterval);
    //    connect(refreshTimer, SIGNAL(timeout()), this, SLOT(paintHUD()));
    connect(refreshTimer, SIGNAL(timeout()), this, SLOT(update()));
}

PrimaryFlightDisplay::~PrimaryFlightDisplay()
{
    refreshTimer->stop();
}


QSize PrimaryFlightDisplay::sizeHint() const
{
    return QSize(width(), (width()*3.0f)/4);
}

void PrimaryFlightDisplay::showEvent(QShowEvent* event)
{
    // React only to internal (pre-display)
    // events
    QWidget::showEvent(event);
    refreshTimer->start(updateInterval);
    emit visibilityChanged(true);
}

void PrimaryFlightDisplay::hideEvent(QHideEvent* event)
{
    // React only to internal (pre-display)
    // events
    refreshTimer->stop();
    QWidget::hideEvent(event);
    emit visibilityChanged(false);
}

qreal constrain(qreal value, qreal min, qreal max) {
    if (value<min) value=min;
    else if(value>max) value=max;
    return value;
}

void PrimaryFlightDisplay::resizeEvent(QResizeEvent *e) {
    QWidget::resizeEvent(e);

    qreal size = e->size().width();
    //if(e->size().height()<size) size = e->size().height();

    lineWidth = constrain(size*LINEWIDTH, 1, 6);
    fineLineWidth = constrain(size*LINEWIDTH*2/3, 1, 2);

    instrumentEdgePen.setWidthF(fineLineWidth);
    //AIEdgePen.setWidthF(fineLineWidth);

    smallTestSize = size * SMALL_TEXT_SIZE;
    mediumTextSize = size * MEDIUM_TEXT_SIZE;
    largeTextSize = size * LARGE_TEXT_SIZE;

    /*
     * Try without layout Change-O-Matic. It was too complicated.
    qreal aspect = e->size().width() / e->size().height();
    if (aspect <= SEPARATE_COMPASS_ASPECTRATIO)
        layout = COMPASS_SEPARATED;
    else
        layout = COMPASS_INTEGRATED;
    */
    // qDebug("Width %d height %d decision %d", e->size().width(), e->size().height(), layout);
}

void PrimaryFlightDisplay::paintEvent(QPaintEvent *event)
{
    // Event is not needed
    // the event is ignored as this widget
    // is refreshed automatically
    Q_UNUSED(event);
    //makeDummyData();
    doPaint();
}

/*
 * Interface towards qgroundcontrol
 */
/**
 *
 * @param uas the UAS/MAV to monitor/display with the HUD
 */
void PrimaryFlightDisplay::setActiveUAS(UASInterface* uas)
{
    if (this->uas != NULL) {
        // Disconnect any previously connected active MAV
        disconnect(this->uas, SIGNAL(attitudeChanged(UASInterface*,double,double,double,quint64)), this, SLOT(updateAttitude(UASInterface*, double, double, double, quint64)));
        disconnect(this->uas, SIGNAL(attitudeChanged(UASInterface*,int,double,double,double,quint64)), this, SLOT(updateAttitude(UASInterface*,int,double, double, double, quint64)));
        disconnect(this->uas, SIGNAL(waypointSelected(int,int)), this, SLOT(selectWaypoint(int, int)));
        disconnect(this->uas, SIGNAL(primarySpeedChanged(UASInterface*, double, quint64)), this, SLOT(updatePrimarySpeed(UASInterface*,double,quint64)));
        disconnect(this->uas, SIGNAL(gpsSpeedChanged(UASInterface*, double, quint64)), this, SLOT(updateGPSSpeed(UASInterface*,double,quint64)));
        disconnect(this->uas, SIGNAL(climbRateChanged(UASInterface*, double, quint64)), this, SLOT(updateClimbRate(UASInterface*, AltitudeMeasurementSource, double, quint64)));
        disconnect(this->uas, SIGNAL(primaryAltitudeChanged(UASInterface*, double, quint64)), this, SLOT(updatePrimaryAltitude(UASInterface*, double, quint64)));
        disconnect(this->uas, SIGNAL(gpsAltitudeChanged(UASInterface*, double, quint64)), this, SLOT(updateGPSAltitude(UASInterface*, double, quint64)));
        disconnect(this->uas, SIGNAL(navigationControllerErrorsChanged(UASInterface*, double, double, double)), this, SLOT(updateNavigationControllerErrors(UASInterface*, double, double, double)));

        //disconnect(this->uas, SIGNAL(batteryChanged(UASInterface*, double, double, double, int)), this, SLOT(updateBattery(UASInterface*, double, double, double, int)));
        //disconnect(this->uas, SIGNAL(statusChanged(UASInterface*,QString,QString)), this, SLOT(updateState(UASInterface*,QString)));
        //disconnect(this->uas, SIGNAL(modeChanged(int,QString,QString)), this, SLOT(updateMode(int,QString,QString)));
        //disconnect(this->uas, SIGNAL(heartbeat(UASInterface*)), this, SLOT(receiveHeartbeat(UASInterface*)));
        //disconnect(this->uas, SIGNAL(armingChanged(bool)), this, SLOT(updateArmed(bool)));
        //disconnect(this->uas, SIGNAL(satelliteCountChanged(double, QString)), this, SLOT(updateSatelliteCount(double, QString)));
        //disconnect(this->uas, SIGNAL(localizationChanged(UASInterface* uas, int fix)), this, SLOT(updateGPSFixType(UASInterface*,int)));
    }

    if (uas) {
        // Now connect the new UAS
        // Setup communication
        connect(uas, SIGNAL(attitudeChanged(UASInterface*,double,double,double,quint64)), this, SLOT(updateAttitude(UASInterface*, double, double, double, quint64)));
        connect(uas, SIGNAL(attitudeChanged(UASInterface*,int,double,double,double,quint64)), this, SLOT(updateAttitude(UASInterface*,int,double, double, double, quint64)));

        //connect(uas, SIGNAL(batteryChanged(UASInterface*, double, double, double, int)), this, SLOT(updateBattery(UASInterface*, double, double, double, int)));
        //connect(uas, SIGNAL(statusChanged(UASInterface*,QString,QString)), this, SLOT(updateState(UASInterface*,QString)));
        //connect(uas, SIGNAL(modeChanged(int,QString,QString)), this, SLOT(updateMode(int,QString,QString)));
        //connect(uas, SIGNAL(heartbeat(UASInterface*)), this, SLOT(receiveHeartbeat(UASInterface*)));
        //connect(uas, SIGNAL(armingChanged(bool)), this, SLOT(updateArmed(bool)));
        //connect(uas, SIGNAL(satelliteCountChanged(double, QString)), this, SLOT(updateSatelliteCount(double, QString)));

        //connect(uas, SIGNAL(localPositionChanged(UASInterface*,double,double,double,quint64)), this, SLOT(updateLocalPosition(UASInterface*,double,double,double,quint64)));
        //connect(uas, SIGNAL(globalPositionChanged(UASInterface*,double,double,double,quint64)), this, SLOT(updateGlobalPosition(UASInterface*,double,double,double,quint64)));
        connect(uas, SIGNAL(waypointSelected(int,int)), this, SLOT(selectWaypoint(int, int)));
        connect(uas, SIGNAL(primarySpeedChanged(UASInterface*, double, quint64)), this, SLOT(updatePrimarySpeed(UASInterface*,double,quint64)));
        connect(uas, SIGNAL(gpsSpeedChanged(UASInterface*, double, quint64)), this, SLOT(updateGPSSpeed(UASInterface*,double,quint64)));
        connect(uas, SIGNAL(climbRateChanged(UASInterface*, double, quint64)), this, SLOT(updateClimbRate(UASInterface*, AltitudeMeasurementSource, double, quint64)));
        connect(uas, SIGNAL(primaryAltitudeChanged(UASInterface*, double, quint64)), this, SLOT(updatePrimaryAltitude(UASInterface*, double, quint64)));
        connect(uas, SIGNAL(gpsAltitudeChanged(UASInterface*, double, quint64)), this, SLOT(updateGPSAltitude(UASInterface*, double, quint64)));
        connect(uas, SIGNAL(navigationControllerErrorsChanged(UASInterface*, double, double, double)), this, SLOT(updateNavigationControllerErrors(UASInterface*, double, double, double)));

        // Set new UAS
        this->uas = uas;
    }
}

void PrimaryFlightDisplay::updateAttitude(UASInterface* uas, double roll, double pitch, double yaw, quint64 timestamp)
{
    Q_UNUSED(uas);
    Q_UNUSED(timestamp);
    if (!isnan(roll) && !isinf(roll) && !isnan(pitch) && !isinf(pitch) && !isnan(yaw) && !isinf(yaw))
    {
        // TODO: Units conversion? // Called from UAS.cc l. 646
        this->roll = roll * (180.0 / M_PI);
        this->pitch = pitch * (180.0 / M_PI);
        yaw = yaw * (180.0 / M_PI);
        if (yaw<0) yaw+=360;
        this->heading = yaw;
    }
    // TODO: Else-part. We really should have an "attitude bad or unknown" indication instead of just freezing.

    //qDebug("r,p,y: %f,%f,%f", roll, pitch, yaw);
}

/*
 * TODO! Implementation or removal of this.
 * Currently a dummy.
 */
void PrimaryFlightDisplay::updateAttitude(UASInterface* uas, int component, double roll, double pitch, double yaw, quint64 timestamp)
{
    Q_UNUSED(uas);
    Q_UNUSED(component);
    Q_UNUSED(timestamp);
    // Called from UAS.cc l. 616
    if (!isnan(roll) && !isinf(roll) && !isnan(pitch) && !isinf(pitch) && !isnan(yaw) && !isinf(yaw)) {
        this->roll = roll * (180.0 / M_PI);
        this->pitch = pitch * (180.0 / M_PI);
        yaw = yaw * (180.0 / M_PI);
        if (yaw<0) yaw+=360;
        this->heading = yaw;
    }
    // qDebug("(2) r,p,y: %f,%f,%f", roll, pitch, yaw);

}

/*
 * TODO! Examine what data comes with this call, should we consider it airspeed, ground speed or
 * should we not consider it at all?
 */
void PrimaryFlightDisplay::updatePrimarySpeed(UASInterface* uas, double speed, quint64 timestamp)
{
    Q_UNUSED(uas);
    Q_UNUSED(timestamp);

    primarySpeed = speed;
    didReceivePrimarySpeed = true;
}

void PrimaryFlightDisplay::updateGPSSpeed(UASInterface* uas, double speed, quint64 timestamp)
{
    Q_UNUSED(uas);
    Q_UNUSED(timestamp);

    groundspeed = speed;
    if (!didReceivePrimarySpeed)
        primarySpeed = speed;
}

void PrimaryFlightDisplay::updateClimbRate(UASInterface* uas, double climbRate, quint64 timestamp) {
    Q_UNUSED(uas);
    Q_UNUSED(timestamp);
    verticalVelocity = climbRate;
}

void PrimaryFlightDisplay::updatePrimaryAltitude(UASInterface* uas, double altitude, quint64 timestamp) {
    Q_UNUSED(uas);
    Q_UNUSED(timestamp);
    primaryAltitude = altitude;
    didReceivePrimaryAltitude = true;
}

void PrimaryFlightDisplay::updateGPSAltitude(UASInterface* uas, double altitude, quint64 timestamp) {
    Q_UNUSED(uas);
    Q_UNUSED(timestamp);
    GPSAltitude = altitude;
    if (!didReceivePrimaryAltitude)
        primaryAltitude = altitude;
}

void PrimaryFlightDisplay::updateNavigationControllerErrors(UASInterface* uas, double altitudeError, double speedError, double xtrackError) {
    Q_UNUSED(uas);
    this->navigationAltitudeError = altitudeError;
    this->navigationSpeedError = speedError;
    this->navigationCrosstrackError = xtrackError;
}


/*
 * Private and such
 */

// TODO: Move to UAS. Real working implementation.
bool PrimaryFlightDisplay::isAirplane() {
    if (!this->uas)
        return false;
    switch(this->uas->getSystemType()) {
    case MAV_TYPE_GENERIC:
    case MAV_TYPE_FIXED_WING:
    case MAV_TYPE_AIRSHIP:
    case MAV_TYPE_FLAPPING_WING:
        return true;
    default:
        return false;
    }
}

// TODO: Implement. Should return true when navigating.
// That would be (APM) in AUTO and RTL modes.
// This could forward to a virtual on UAS bool isNavigatingAutonomusly() or whatever.
bool PrimaryFlightDisplay::shouldDisplayNavigationData() {
    return true;
}

void PrimaryFlightDisplay::drawTextCenter (
        QPainter& painter,
        QString text,
        float pixelSize,
        float x,
        float y)
{
    font.setPixelSize(pixelSize);
    painter.setFont(font);

    QFontMetrics metrics = QFontMetrics(font);
    QRect bounds = metrics.boundingRect(text);
    int flags = Qt::AlignCenter |  Qt::TextDontClip; // For some reason the bounds rect is too small!
    painter.drawText(x /*+bounds.x()*/ -bounds.width()/2, y /*+bounds.y()*/ -bounds.height()/2, bounds.width(), bounds.height(), flags, text);
}

void PrimaryFlightDisplay::drawTextLeftCenter (
        QPainter& painter,
        QString text,
        float pixelSize,
        float x,
        float y)
{
    font.setPixelSize(pixelSize);
    painter.setFont(font);

    QFontMetrics metrics = QFontMetrics(font);
    QRect bounds = metrics.boundingRect(text);
    int flags = Qt::AlignLeft | Qt::TextDontClip; // For some reason the bounds rect is too small!
    painter.drawText(x /*+bounds.x()*/, y /*+bounds.y()*/ -bounds.height()/2, bounds.width(), bounds.height(), flags, text);
}

void PrimaryFlightDisplay::drawTextRightCenter (
        QPainter& painter,
        QString text,
        float pixelSize,
        float x,
        float y)
{
    font.setPixelSize(pixelSize);
    painter.setFont(font);

    QFontMetrics metrics = QFontMetrics(font);
    QRect bounds = metrics.boundingRect(text);
    int flags = Qt::AlignRight | Qt::TextDontClip; // For some reason the bounds rect is too small!
    painter.drawText(x /*+bounds.x()*/ -bounds.width(), y /*+bounds.y()*/ -bounds.height()/2, bounds.width(), bounds.height(), flags, text);
}

void PrimaryFlightDisplay::drawTextCenterTop (
        QPainter& painter,
        QString text,
        float pixelSize,
        float x,
        float y)
{
    font.setPixelSize(pixelSize);
    painter.setFont(font);

    QFontMetrics metrics = QFontMetrics(font);
    QRect bounds = metrics.boundingRect(text);
    int flags = Qt::AlignCenter | Qt::TextDontClip; // For some reason the bounds rect is too small!
    painter.drawText(x /*+bounds.x()*/ -bounds.width()/2, y+bounds.height() /*+bounds.y()*/, bounds.width(), bounds.height(), flags, text);
}

void PrimaryFlightDisplay::drawTextCenterBottom (
        QPainter& painter,
        QString text,
        float pixelSize,
        float x,
        float y)
{
    font.setPixelSize(pixelSize);
    painter.setFont(font);

    QFontMetrics metrics = QFontMetrics(font);
    QRect bounds = metrics.boundingRect(text);
    int flags = Qt::AlignCenter;
    painter.drawText(x /*+bounds.x()*/ -bounds.width()/2, y /*+bounds.y()*/, bounds.width(), bounds.height(), flags, text);
}

void PrimaryFlightDisplay::drawInstrumentBackground(QPainter& painter, QRectF edge) {
    painter.setPen(instrumentEdgePen);
    painter.drawRect(edge);
}

void PrimaryFlightDisplay::fillInstrumentBackground(QPainter& painter, QRectF edge) {
    painter.setPen(instrumentEdgePen);
    painter.setBrush(instrumentBackground);
    painter.drawRect(edge);
    painter.setBrush(Qt::NoBrush);
}

void PrimaryFlightDisplay::fillInstrumentOpagueBackground(QPainter& painter, QRectF edge) {
    painter.setPen(instrumentEdgePen);
    painter.setBrush(instrumentOpagueBackground);
    painter.drawRect(edge);
    painter.setBrush(Qt::NoBrush);
}

qreal pitchAngleToTranslation(qreal viewHeight, float pitch) {
    return pitch * viewHeight / PITCHTRANSLATION;
}

void PrimaryFlightDisplay::drawAIAirframeFixedFeatures(QPainter& painter, QRectF area) {
    // red line from -7/10 to -5/10 half-width
    // red line from 7/10 to 5/10 half-width
    // red slanted line from -2/10 half-width to 0
    // red slanted line from 2/10 half-width to 0
    // red arrow thing under roll scale
    // prepareTransform(painter, width, height);
    painter.resetTransform();
    painter.translate(area.center());

    qreal w = area.width();
    qreal h = area.height();

    QPen pen;
    pen.setWidthF(lineWidth * 1.5);
    pen.setColor(redColor);
    painter.setPen(pen);

    float length = 0.15;
    float side = 0.5;
    // The 2 lines at sides.
    painter.drawLine(QPointF(-side*w, 0), QPointF(-(side-length)*w, 0));
    painter.drawLine(QPointF(side*w, 0), QPointF((side-length)*w, 0));

    float rel = length/qSqrt(2);
    // The gull
    painter.drawLine(QPointF(rel*w, rel*w/2), QPoint(0, 0));
    painter.drawLine(QPointF(-rel*w, rel*w/2), QPoint(0, 0));

    // The roll scale marker.
    QPainterPath markerPath(QPointF(0, -w*ROLL_SCALE_RADIUS+1));
    markerPath.lineTo(-h*ROLL_SCALE_MARKERWIDTH/2, -w*(ROLL_SCALE_RADIUS-ROLL_SCALE_MARKERHEIGHT)+1);
    markerPath.lineTo(h*ROLL_SCALE_MARKERWIDTH/2, -w*(ROLL_SCALE_RADIUS-ROLL_SCALE_MARKERHEIGHT)+1);
    markerPath.closeSubpath();
    painter.drawPath(markerPath);
}

inline qreal min4(qreal a, qreal b, qreal c, qreal d) {
    if(b<a) a=b;
    if(c<a) a=c;
    if(d<a) a=d;
    return a;
}

inline qreal max4(qreal a, qreal b, qreal c, qreal d) {
    if(b>a) a=b;
    if(c>a) a=c;
    if(d>a) a=d;
    return a;
}

void PrimaryFlightDisplay::drawAIGlobalFeatures(
        QPainter& painter,
        QRectF mainArea,
        QRectF paintArea) {

    painter.resetTransform();
    painter.translate(mainArea.center());

    qreal pitchPixels = pitchAngleToTranslation(mainArea.height(), pitch);
    qreal gradientEnd = pitchAngleToTranslation(mainArea.height(), 60);

    //painter.rotate(-roll);
    //painter.translate(0, pitchPixels);

    //    QTransform forwardTransform;
    //forwardTransform.translate(mainArea.center().x(), mainArea.center().y());
    painter.rotate(-roll);
    painter.translate(0, pitchPixels);

    // Calculate the radius of area we need to paint to cover all.
    QTransform rtx = painter.transform().inverted();

    QPointF topLeft = rtx.map(paintArea.topLeft());
    QPointF topRight = rtx.map(paintArea.topRight());
    QPointF bottomLeft = rtx.map(paintArea.bottomLeft());
    QPointF bottomRight = rtx.map(paintArea.bottomRight());
    // Just KISS... make a rectangluar basis.
    qreal minx = min4(topLeft.x(), topRight.x(), bottomLeft.x(), bottomRight.x());
    qreal maxx = max4(topLeft.x(), topRight.x(), bottomLeft.x(), bottomRight.x());
    qreal miny = min4(topLeft.y(), topRight.y(), bottomLeft.y(), bottomRight.y());
    qreal maxy = max4(topLeft.y(), topRight.y(), bottomLeft.y(), bottomRight.y());

    QPointF hzonLeft = QPoint(minx, 0);
    QPointF hzonRight = QPoint(maxx, 0);

    QPainterPath skyPath(hzonLeft);
    skyPath.lineTo(QPointF(minx, miny));
    skyPath.lineTo(QPointF(maxx, miny));
    skyPath.lineTo(hzonRight);
    skyPath.closeSubpath();

    // TODO: The gradient is wrong now.
    QLinearGradient skyGradient(0, -gradientEnd, 0, 0);
    skyGradient.setColorAt(0, QColor::fromHsvF(0.6, 1.0, 0.7));
    skyGradient.setColorAt(1, QColor::fromHsvF(0.6, 0.25, 0.9));
    QBrush skyBrush(skyGradient);
    painter.fillPath(skyPath, skyBrush);

    QPainterPath groundPath(hzonRight);
    groundPath.lineTo(maxx, maxy);
    groundPath.lineTo(minx, maxy);
    groundPath.lineTo(hzonLeft);
    groundPath.closeSubpath();

    QLinearGradient groundGradient(0, gradientEnd, 0, 0);
    groundGradient.setColorAt(0, QColor::fromHsvF(0.25, 1, 0.5));
    groundGradient.setColorAt(1, QColor::fromHsvF(0.25, 0.25, 0.5));
    QBrush groundBrush(groundGradient);
    painter.fillPath(groundPath, groundBrush);

    QPen pen;
    pen.setWidthF(lineWidth);
    pen.setColor(greenColor);
    painter.setPen(pen);

    QPointF start(-mainArea.width(), 0);
    QPoint end(mainArea.width(), 0);
    painter.drawLine(start, end);
}

void PrimaryFlightDisplay::drawPitchScale(
        QPainter& painter,
        QRectF area,
        float intrusion,
        bool drawNumbersLeft,
        bool drawNumbersRight
        ) {

    // The area should be quadratic but if not width is the major size.
    qreal w = area.width();
    if (w<area.height()) w = area.height();

    QPen pen;
    pen.setWidthF(lineWidth);
    pen.setColor(Qt::white);
    painter.setPen(pen);

    QTransform savedTransform = painter.transform();

    // find the mark nearest center
    int snap = qRound((double)(pitch/PITCH_SCALE_RESOLUTION))*PITCH_SCALE_RESOLUTION;
    int _min = snap-PITCH_SCALE_HALFRANGE;
    int _max = snap+PITCH_SCALE_HALFRANGE;
    for (int degrees=_min; degrees<=_max; degrees+=PITCH_SCALE_RESOLUTION) {
        bool isMajor = degrees % (PITCH_SCALE_RESOLUTION*2) == 0;
        float linewidth =  isMajor ? PITCH_SCALE_MAJORWIDTH : PITCH_SCALE_MINORWIDTH;
        if (abs(degrees) > PITCH_SCALE_WIDTHREDUCTION_FROM) {
            // we want: 1 at PITCH_SCALE_WIDTHREDUCTION_FROM and PITCH_SCALE_WIDTHREDUCTION at 90.
            // That is PITCH_SCALE_WIDTHREDUCTION + (1-PITCH_SCALE_WIDTHREDUCTION) * f(pitch)
            // where f(90)=0 and f(PITCH_SCALE_WIDTHREDUCTION_FROM)=1
            // f(p) = (90-p) * 1/(90-PITCH_SCALE_WIDTHREDUCTION_FROM)
            // or PITCH_SCALE_WIDTHREDUCTION + f(pitch) - f(pitch) * PITCH_SCALE_WIDTHREDUCTION
            // or PITCH_SCALE_WIDTHREDUCTION (1-f(pitch)) + f(pitch)
            int fromVertical = abs(pitch>=0 ? 90-pitch : -90-pitch);
            float temp = fromVertical * 1/(90.0f-PITCH_SCALE_WIDTHREDUCTION_FROM);
            linewidth *= (PITCH_SCALE_WIDTHREDUCTION * (1-temp) + temp);
        }

        float shift = pitchAngleToTranslation(w, pitch-degrees);

        // TODO: Intrusion detection and evasion. That is, don't draw
        // where the compass has intruded.

        painter.translate(0, shift);
        QPointF start(-linewidth*w, 0);
        QPointF end(linewidth*w, 0);
        painter.drawLine(start, end);

        if (isMajor && (drawNumbersLeft||drawNumbersRight)) {
            int displayDegrees = degrees;
            if(displayDegrees>90) displayDegrees = 180-displayDegrees;
            else if (displayDegrees<-90) displayDegrees = -180 - displayDegrees;
            if (SHOW_ZERO_ON_SCALES || degrees) {
                QString s_number; //= QString("%d").arg(degrees);
                s_number.sprintf("%d", displayDegrees);
                if (drawNumbersLeft)  drawTextRightCenter(painter, s_number, mediumTextSize, -PITCH_SCALE_MAJORWIDTH * w-10, 0);
                if (drawNumbersRight) drawTextLeftCenter(painter, s_number, mediumTextSize, PITCH_SCALE_MAJORWIDTH * w+10, 0);
            }
        }

        painter.setTransform(savedTransform);
    }
}

void PrimaryFlightDisplay::drawRollScale(
        QPainter& painter,
        QRectF area,
        bool drawTicks,
        bool drawNumbers) {

    qreal w = area.width();
    if (w<area.height()) w = area.height();

    QPen pen;
    pen.setWidthF(lineWidth);
    pen.setColor(Qt::white);
    painter.setPen(pen);

    // We should really do these transforms but they are assumed done by caller.
    // painter.resetTransform();
    // painter.translate(area.center());
    // painter.rotate(roll);

    qreal _size = w * ROLL_SCALE_RADIUS*2;
    QRectF arcArea(-_size/2, - _size/2, _size, _size);
    painter.drawArc(arcArea, (90-ROLL_SCALE_RANGE)*16, ROLL_SCALE_RANGE*2*16);
    // painter.drawEllipse(QPoint(0,0),200,200);
    if (drawTicks) {
        int length = sizeof(tickValues)/sizeof(int);
        qreal previousRotation = 0;
        for (int i=0; i<length*2+1; i++) {
            int degrees = (i==length) ? 0 : (i>length) ?-tickValues[i-length-1] : tickValues[i];
            //degrees = 180 - degrees;
            painter.rotate(degrees - previousRotation);
            previousRotation = degrees;

            QPointF start(0, -_size/2);
            QPointF end(0, -(1.0+ROLL_SCALE_TICKMARKLENGTH)*_size/2);

            painter.drawLine(start, end);

            QString s_number; //= QString("%d").arg(degrees);
            if (SHOW_ZERO_ON_SCALES || degrees)
                s_number.sprintf("%d", abs(degrees));

            if (drawNumbers) {
                drawTextCenterBottom(painter, s_number, mediumTextSize, 0, -(ROLL_SCALE_RADIUS+ROLL_SCALE_TICKMARKLENGTH*1.7)*w);
            }
        }
    }
}

void PrimaryFlightDisplay::drawAIAttitudeScales(
        QPainter& painter,
        QRectF area,
        float intrusion
        ) {
    // To save computations, we do these transformations once for both scales:
    painter.resetTransform();
    painter.translate(area.center());
    painter.rotate(-roll);
    QTransform saved = painter.transform();

    drawRollScale(painter, area, true, true);
    painter.setTransform(saved);
    drawPitchScale(painter, area, intrusion, true, true);
}

void PrimaryFlightDisplay::drawAICompassDisk(QPainter& painter, QRectF area, float halfspan) {
    float start = heading - halfspan;
    float end = heading + halfspan;

    int firstTick = ceil(start / COMPASS_DISK_RESOLUTION) * COMPASS_DISK_RESOLUTION;
    int lastTick = floor(end / COMPASS_DISK_RESOLUTION) * COMPASS_DISK_RESOLUTION;

    float radius = area.width()/2;
    float innerRadius = radius * 0.96;
    painter.resetTransform();
    painter.setBrush(instrumentBackground);
    painter.setPen(instrumentEdgePen);
    painter.drawEllipse(area);
    painter.setBrush(Qt::NoBrush);

    QPen scalePen(Qt::black);
    scalePen.setWidthF(fineLineWidth);

    for (int tickYaw = firstTick; tickYaw <= lastTick; tickYaw += COMPASS_DISK_RESOLUTION) {
        int displayTick = tickYaw;
        if (displayTick < 0) displayTick+=360;
        else if (displayTick>=360) displayTick-=360;

        // yaw is in center.
        float off = tickYaw - heading;
        // wrap that to ]-180..180]
        if (off<=-180) off+= 360; else if (off>180) off -= 360;

        painter.translate(area.center());
        painter.rotate(off);
        bool drewArrow = false;
        bool isMajor = displayTick % COMPASS_DISK_MAJORTICK == 0;

        if (displayTick==30 || displayTick==60 ||
                displayTick==120 || displayTick==150 ||
                displayTick==210 || displayTick==240 ||
                displayTick==300 || displayTick==330) {
            // draw a number
            QString s_number;
            s_number.sprintf("%d", displayTick/10);
            painter.setPen(scalePen);
            drawTextCenter(painter, s_number, /*COMPASS_SCALE_TEXT_SIZE*radius*/ smallTestSize, 0, -innerRadius*0.75);
        } else {
            if (displayTick % COMPASS_DISK_ARROWTICK == 0) {
                if (displayTick!=0) {
                    QPainterPath markerPath(QPointF(0, -innerRadius*(1-COMPASS_DISK_MARKERHEIGHT/2)));
                    markerPath.lineTo(innerRadius*COMPASS_DISK_MARKERWIDTH/4, -innerRadius);
                    markerPath.lineTo(-innerRadius*COMPASS_DISK_MARKERWIDTH/4, -innerRadius);
                    markerPath.closeSubpath();
                    painter.setPen(scalePen);
                    painter.setBrush(Qt::SolidPattern);
                    painter.drawPath(markerPath);
                    painter.setBrush(Qt::NoBrush);
                    drewArrow = true;
                }
                if (displayTick%90 == 0) {
                    // Also draw a label
                    QString name = compassWindNames[displayTick / 45];
                    painter.setPen(scalePen);
                    drawTextCenter(painter, name, mediumTextSize, 0, -innerRadius*0.75);
                }
            }
        }
        // draw the scale lines. If an arrow was drawn, stay off from it.

        QPointF p_start = drewArrow ? QPoint(0, -innerRadius*0.94) : QPoint(0, -innerRadius);
        QPoint p_end = isMajor ? QPoint(0, -innerRadius*0.86) : QPoint(0, -innerRadius*0.90);

        painter.setPen(scalePen);
        painter.drawLine(p_start, p_end);
        painter.resetTransform();
    }

    painter.setPen(scalePen);
    //painter.setBrush(Qt::SolidPattern);
    painter.translate(area.center());
    QPainterPath markerPath(QPointF(0, -radius-2));
    markerPath.lineTo(radius*COMPASS_DISK_MARKERWIDTH/2,  -radius-radius*COMPASS_DISK_MARKERHEIGHT-2);
    markerPath.lineTo(-radius*COMPASS_DISK_MARKERWIDTH/2, -radius-radius*COMPASS_DISK_MARKERHEIGHT-2);
    markerPath.closeSubpath();
    painter.drawPath(markerPath);

    qreal digitalCompassYCenter = -radius*0.52;
    qreal digitalCompassHeight = radius*0.28;

    QPointF digitalCompassBottom(0, digitalCompassYCenter+digitalCompassHeight);
    QPointF  digitalCompassAbsoluteBottom = painter.transform().map(digitalCompassBottom);

    qreal digitalCompassUpshift = digitalCompassAbsoluteBottom.y()>height() ? digitalCompassAbsoluteBottom.y()-height() : 0;

    QRectF digitalCompassRect(-radius/3, -radius*0.52-digitalCompassUpshift, radius*2/3, radius*0.28);
    painter.setPen(instrumentEdgePen);
    painter.drawRoundedRect(digitalCompassRect, instrumentEdgePen.widthF()*2/3, instrumentEdgePen.widthF()*2/3);

    /* final safeguard for really stupid systems */
    int digitalCompassValue = static_cast<int>(qRound((double)heading)) % 360;

    QString s_digitalCompass;
    s_digitalCompass.sprintf("%03d", digitalCompassValue);

    QPen pen;
    pen.setWidthF(lineWidth);
    pen.setColor(Qt::white);
    painter.setPen(pen);

    drawTextCenter(painter, s_digitalCompass, largeTextSize, 0, -radius*0.38-digitalCompassUpshift);

//  dummy
//  navigationTargetBearing = 10;
//  navigationCrosstrackError = 500;

    // The CDI
    if (shouldDisplayNavigationData() && navigationTargetBearing != UNKNOWN_ATTITUDE && !isinf(navigationCrosstrackError)) {
        painter.resetTransform();
        painter.translate(area.center());
        // TODO : Sign might be wrong?
        // TODO : The case where error exceeds max. Truncate to max. and make that visible somehow.
        bool errorBeyondRadius = false;
        if (abs(navigationCrosstrackError) > CROSSTRACK_MAX) {
            errorBeyondRadius = true;
            navigationCrosstrackError = navigationCrosstrackError>0 ? CROSSTRACK_MAX : -CROSSTRACK_MAX;
        }

        float r = radius * CROSSTRACK_RADIUS;
        float x = navigationCrosstrackError / CROSSTRACK_MAX * r;
        float y = qSqrt(r*r - x*x); // the positive y, there is also a negative.

        float sillyHeading = 0;
        float angle = sillyHeading - navigationTargetBearing; // TODO: sign.
        painter.rotate(-angle);

        QPen pen;
        pen.setWidthF(lineWidth);
        pen.setColor(Qt::black);
        painter.setPen(pen);

        painter.drawLine(QPointF(x, y), QPointF(x, -y));
    }
}

/*
void PrimaryFlightDisplay::drawSeparateCompassDisk(QPainter& painter, QRectF area) {
    float radius = area.width()/2;
    float innerRadius = radius * 0.96;
    painter.resetTransform();

    painter.setBrush(instrumentOpagueBackground);
    painter.setPen(instrumentEdgePen);
    painter.drawEllipse(area);
    painter.setBrush(Qt::NoBrush);

    QPen scalePen(Qt::white);
    scalePen.setWidthF(fineLineWidth);

    for (int displayTick=0; displayTick<360; displayTick+=COMPASS_SEPARATE_DISK_RESOLUTION) {
        // yaw is in center.
        float off = displayTick - heading;
        // wrap that to ]-180..180]
        if (off<=-180) off+= 360; else if (off>180) off -= 360;

        painter.translate(area.center());
        painter.rotate(off);
        bool drewArrow = false;
        bool isMajor = displayTick % COMPASS_DISK_MAJORTICK == 0;

        if (displayTick==30 || displayTick==60 ||
                displayTick==120 || displayTick==150 ||
                displayTick==210 || displayTick==240 ||
                displayTick==300 || displayTick==330) {
            // draw a number
            QString s_number;
            s_number.sprintf("%d", displayTick/10);
            painter.setPen(scalePen);
            drawTextCenter(painter, s_number, mediumTextSize, 0, -innerRadius*0.75);
        } else {
            if (displayTick % COMPASS_DISK_ARROWTICK == 0) {
                if (displayTick!=0) {
                    QPainterPath markerPath(QPointF(0, -innerRadius*(1-COMPASS_DISK_MARKERHEIGHT/2)));
                    markerPath.lineTo(innerRadius*COMPASS_DISK_MARKERWIDTH/4, -innerRadius);
                    markerPath.lineTo(-innerRadius*COMPASS_DISK_MARKERWIDTH/4, -innerRadius);
                    markerPath.closeSubpath();
                    painter.setPen(scalePen);
                    painter.setBrush(Qt::SolidPattern);
                    painter.drawPath(markerPath);
                    painter.setBrush(Qt::NoBrush);
                    drewArrow = true;
                }
                if (displayTick%90 == 0) {
                    // Also draw a label
                    QString name = compassWindNames[displayTick / 45];
                    painter.setPen(scalePen);
                    drawTextCenter(painter, name, mediumTextSize, 0, -innerRadius*0.75);
                }
            }
        }
        // draw the scale lines. If an arrow was drawn, stay off from it.

        QPointF p_start = drewArrow ? QPoint(0, -innerRadius*0.94) : QPoint(0, -innerRadius);
        QPoint p_end = isMajor ? QPoint(0, -innerRadius*0.86) : QPoint(0, -innerRadius*0.90);

        painter.setPen(scalePen);
        painter.drawLine(p_start, p_end);
        painter.resetTransform();
    }

    painter.setPen(scalePen);
    //painter.setBrush(Qt::SolidPattern);
    painter.translate(area.center());
    QPainterPath markerPath(QPointF(0, -radius-2));
    markerPath.lineTo(radius*COMPASS_DISK_MARKERWIDTH/2,  -radius-radius*COMPASS_DISK_MARKERHEIGHT-2);
    markerPath.lineTo(-radius*COMPASS_DISK_MARKERWIDTH/2, -radius-radius*COMPASS_DISK_MARKERHEIGHT-2);
    markerPath.closeSubpath();
    painter.drawPath(markerPath);

    QRectF headingNumberRect(-radius/3, radius*0.12, radius*2/3, radius*0.28);
    painter.setPen(instrumentEdgePen);
    painter.drawRoundedRect(headingNumberRect, instrumentEdgePen.widthF()*2/3, instrumentEdgePen.widthF()*2/3);

    //    if (heading < 0) heading += 360;
    //    else if (heading >= 360) heading -= 360;
    int yawCompass = static_cast<int>(heading) % 360;

    QString yawAngle;
    yawAngle.sprintf("%03d", yawCompass);

    QPen pen;
    pen.setWidthF(lineWidth);
    pen.setColor(Qt::white);
    painter.setPen(pen);

    drawTextCenter(painter, yawAngle, largeTextSize, 0, radius/4);
}
*/

void PrimaryFlightDisplay::drawAltimeter(
        QPainter& painter,
        QRectF area, // the area where to draw the tape.
        float primaryAltitude,
        float secondaryAltitude,
        float vv
    ) {

    painter.resetTransform();
    fillInstrumentBackground(painter, area);

    QPen pen;
    pen.setWidthF(lineWidth);

    pen.setColor(Qt::white);
    painter.setPen(pen);

    float h = area.height();
    float w = area.width();
    float secondaryAltitudeBoxHeight = mediumTextSize * 2;
    // The height where we being with new tickmarks.
    float effectiveHalfHeight = h*0.45;

    // not yet implemented: Display of secondary altitude.
    // if (isAirplane())
    //    effectiveHalfHeight-= secondaryAltitudeBoxHeight;

    float markerHalfHeight = mediumTextSize*0.8;
    float leftEdge = instrumentEdgePen.widthF()*2;
    float rightEdge = w-leftEdge;
    float tickmarkLeft = leftEdge;
    float tickmarkRightMajor = tickmarkLeft+TAPE_GAUGES_TICKWIDTH_MAJOR*w;
    float tickmarkRightMinor = tickmarkLeft+TAPE_GAUGES_TICKWIDTH_MINOR*w;
    float numbersLeft = 0.42*w;
    float markerTip = (tickmarkLeft*2+tickmarkRightMajor)/3;
    float scaleCenterAltitude = primaryAltitude == UNKNOWN_ALTITUDE ? 0 : primaryAltitude;

    // altitude scale
#ifdef ALTIMETER_PROJECTED
    float range = 1.2;
    float start = scaleCenterAltitude - ALTIMETER_PROJECTED_SPAN/2;
    float end = scaleCenterAltitude + ALTIMETER_PROJECTED_SPAN/2;
    int firstTick = ceil(start / ALTIMETER_PROJECTED_RESOLUTION) * ALTIMETER_PROJECTED_RESOLUTION;
    int lastTick = floor(end / ALTIMETER_PROJECTED_RESOLUTION) * ALTIMETER_PROJECTED_RESOLUTION;
    for (int tickAlt = firstTick; tickAlt <= lastTick; tickAlt += ALTIMETER_PROJECTED_RESOLUTION) {
        // a number between 0 and 1. Use as radians directly.
        float r = range*(tickAlt-altitude)/(ALTIMETER_PROJECTED_SPAN/2);
        float y = effectiveHalfHeight * sin(r);
        scale = cos(r);
        if (scale<0) scale = -scale;
        bool hasText = tickAlt % ALTIMETER_PROJECTED_MAJOR_RESOLUTION == 0;
#else
    float start = scaleCenterAltitude - ALTIMETER_LINEAR_SPAN/2;
    float end = scaleCenterAltitude + ALTIMETER_LINEAR_SPAN/2;
    int firstTick = ceil(start / ALTIMETER_LINEAR_RESOLUTION) * ALTIMETER_LINEAR_RESOLUTION;
    int lastTick = floor(end / ALTIMETER_LINEAR_RESOLUTION) * ALTIMETER_LINEAR_RESOLUTION;
    for (int tickAlt = firstTick; tickAlt <= lastTick; tickAlt += ALTIMETER_LINEAR_RESOLUTION) {
        float y = (tickAlt-scaleCenterAltitude)*effectiveHalfHeight/(ALTIMETER_LINEAR_SPAN/2);
        bool isMajor = tickAlt % ALTIMETER_LINEAR_MAJOR_RESOLUTION == 0;
#endif
        painter.resetTransform();
        painter.translate(area.left(), area.center().y() - y);
        pen.setColor(tickAlt<0 ? redColor : Qt::white);
        painter.setPen(pen);
        if (isMajor) {
            painter.drawLine(tickmarkLeft, 0, tickmarkRightMajor, 0);
            QString s_alt;
            s_alt.sprintf("%d", abs(tickAlt));
            drawTextLeftCenter(painter, s_alt, mediumTextSize, numbersLeft, 0);
        } else {
            painter.drawLine(tickmarkLeft, 0, tickmarkRightMinor, 0);
        }
    }

    QPainterPath markerPath(QPoint(markerTip, 0));