[Qgis-developer] MapCanvas->mapRenderer->distanceArea->bearing Returns a NaN

[Oscar De Leon]

Hello everybody:

I'm working in a simple application that shows the bearing and distance from
a reference point to the cursor position, but when I'm trying to calcute
them, distanceArea of MapRenderer returns a NaN
I've checked the configuration of mapcanvas and every thing looks fine. This
is a chunk of code where I do the configuration:

QString fileName = "config.xml";
        configMgt = new ConfigMgt(fileName, this);
        QgsProviderRegistry::instance(configMgt->sPluginDir);
        QgsApplication::setPkgDataPath(configMgt->sPkgDir);
        QgsApplication::setPrefixPath(configMgt->sPkgDir);

        // Add Map Canvas
        mpMapCanvas = new QgsMapCanvas(0, 0);
        mpMapCanvas->enableAntiAliasing(true);
        mpMapCanvas->useImageToRender(false);
        mpMapCanvas->freeze(false);
        mpMapCanvas->setVisible(true);
        mpMapCanvas->refresh();
        mpMapCanvas->show();
        ui.Layout->addWidget(mpMapCanvas);
        crs = new QgsCoordinateReferenceSystem(3344,
                    QgsCoordinateReferenceSystem::InternalCrsId);


And this is the code where I show the Result

QString sLat(QVariant(getDegreesY(pos)).toString() + QChar(0xB0)+
QVariant(getMinutesY(pos)).toString());
    sLat.append(pos.y() < 0 ? " S" : " N");
    this->ui.lbCursorPosLat->setText(sLat);
    QString sLon(QVariant(getDegreesX(pos)).toString() + QChar(0xB0)+
QVariant(getMinutesX(pos)).toString());
    sLon.append(pos.x() < 0 ? " W" : " E");
    this->ui.lbCursorPosLon->setText(sLon);
        //Calculo de RNG y BRG
        QgsDistanceArea *daDistancia =new QgsDistanceArea();
        daDistancia=mpMapCanvas->mapRenderer()->distanceArea();
        daDistancia->setProjectionsEnabled(false);
        QString * sRNG = new QString();
        QgsPoint *uno=new QgsPoint();
        QgsPoint *dos=new QgsPoint();
        uno->setX(pos.x());
        uno->setY(pos.y());

        dos->setX(ptReference.x());
        dos->setY(ptReference.y());


        sRNG->setNum(toNM(daDistancia->measureLine(*uno, *dos)), 10, 0);
        this->ui.laLat->setText(*sRNG + " NM");

        QString * sBRG = new QString();

        double dDeg =
RAD2DEG(/*daDistancia*/mpMapCanvas->mapRenderer()->distanceArea()->bearing(ptReference,pos));
        dDeg = dDeg > 0 ? dDeg : 360 + dDeg;
        dDeg = dDeg > dCorrectionReference ? dDeg - dCorrectionReference :
360   - dCorrectionReference + dDeg;
        sBRG->setNum(dDeg, 10, 1);
        this->ui.laLon->setText(*sBRG + " " + QChar(0xB0));

Thank you for your help
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