Marble 绘制线

#include <QtGui/QApplication>
#include <marble/MarbleWidget.h>
#include <marble/GeoPainter.h>
#include <marble/GeoDataLineString.h>

using namespace Marble;

class MyMarbleWidget : public MarbleWidget
{
    public:
    virtual void customPaint(GeoPainter* painter);
};

void MyMarbleWidget::customPaint(GeoPainter* painter) {

    GeoDataCoordinates France( 2.2, 48.52, 0.0, GeoDataCoordinates::Degree );
    painter->setPen( QColor( 0, 0, 0 ) );
    painter->drawText( France, "France" );

    GeoDataCoordinates Canada( -77.02, 48.52, 0.0, GeoDataCoordinates::Degree );
    painter->setPen( QColor( 0, 0, 0 ) );
    painter->drawText( Canada, "Canada" );

    //A line from France to Canada without tessellation

    GeoDataLineString shapeNoTessellation( NoTessellation );
    shapeNoTessellation << France << Canada;

    painter->setPen( oxygenSkyBlue4 );
    painter->drawPolyline( shapeNoTessellation );

    //The same line, but with tessellation

    GeoDataLineString shapeTessellate( Tessellate );
    shapeTessellate << France << Canada;

    painter->setPen( oxygenBrickRed4 );
    painter->drawPolyline( shapeTessellate );

    //Now following the latitude circles

    GeoDataLineString shapeLatitudeCircle( RespectLatitudeCircle | Tessellate );
    shapeLatitudeCircle << France << Canada;

    painter->setPen( oxygenForestGreen4 );
    painter->drawPolyline( shapeLatitudeCircle );
}

int main(int argc, char** argv) {

    QApplication app(argc,argv);

    // Create a Marble QWidget without a parent
    MarbleWidget *mapWidget = new MyMarbleWidget();

    // Load the OpenStreetMap map
    mapWidget->setMapThemeId("earth/plain/plain.dgml");

    mapWidget->show();

    return app.exec();
}