File indexing completed on 2024-12-08 09:32:24

 // SPDX-License-Identifier: LGPL-2.1-or-later
 //
 // SPDX-FileCopyrightText: 2014 Dennis Nienhüser <nienhueser@kde.org>
 //
 
 #include "squad-interpolation.h"
 
 #include <marble/MarbleGlobal.h>
 #include <marble/GeoDataLatLonAltBox.h>
 #include <marble/GeoDataDocument.h>
 #include <marble/GeoDataPlacemark.h>
 #include <marble/GeoDataTreeModel.h>
 #include <marble/MarblePlacemarkModel.h>
 #include <marble/GeoDataLinearRing.h>
 #include <marble/MarbleColors.h>
 #include <marble/MarbleMath.h>
 #include <marble/ViewportParams.h>
 
 #include <QTimer>
 
 namespace Marble
 {
 
 MyPaintLayer::MyPaintLayer ( MarbleWidget *widget ) :
     m_widget ( widget ),
     m_fraction ( 0.0 ),
     m_delta( 0.02 ),
     m_index ( 0 )
 {
     GeoDataCoordinates::Unit const degree = GeoDataCoordinates::Degree;
     m_cities << GeoDataCoordinates(  7.64573, 45.04981, 0.0, degree ); // Torino
     m_cities << GeoDataCoordinates(  8.33439, 49.01673, 0.0, degree ); // Karlsruhe
     m_cities << GeoDataCoordinates( 14.41637, 50.09329, 0.0, degree ); // Praha
     m_cities << GeoDataCoordinates( 15.97254, 45.80268, 0.0, degree ); // Zagred
     addInterpolatedPoint();
 }
 
 QStringList MyPaintLayer::renderPosition() const
 {
     return QStringList(QStringLiteral("USER_TOOLS"));
 }
 
 bool MyPaintLayer::render ( GeoPainter *painter, ViewportParams *viewport, const QString &, GeoSceneLayer * )
 {
     if ( m_index < 20 ) {
         // Gray dotted line connects all current cities
         QPen grayPen = Marble::Oxygen::aluminumGray4;
         grayPen.setWidth ( 3 );
         grayPen.setStyle ( Qt::DotLine );
         painter->setPen ( grayPen );
         painter->drawPolyline ( m_cities );
     }
 
     // Blue circle around each city
     painter->setBrush ( QBrush ( QColor ( Marble::Oxygen::skyBlue4 ) ) );
     painter->setPen ( QColor ( Marble::Oxygen::aluminumGray4 ) );
     for ( int i = 0; i < m_cities.size(); ++i ) {
         painter->drawEllipse ( m_cities[i], 32, 32 );
     }
 
     if (m_index < 10) {
         // Show how squad interpolation works internally
         Q_ASSERT( m_cities.size() == 4 );
         painter->setBrush ( QBrush ( QColor ( Marble::Oxygen::grapeViolet4 ) ) );
         painter->setPen ( QColor ( Marble::Oxygen::aluminumGray4 ) );
         GeoDataCoordinates a2 = basePoint( m_cities[0], m_cities[1], m_cities[2] );
         painter->drawEllipse ( a2, 8, 8 );
         qreal x, y;
         if ( viewport->screenCoordinates ( a2, x, y ) ) {
             painter->drawText(x+5, y, QStringLiteral("A"));
         }
         GeoDataCoordinates b1 = basePoint( m_cities[1], m_cities[2], m_cities[3] );
         painter->drawEllipse ( b1, 8, 8 );
         if ( viewport->screenCoordinates ( b1, x, y ) ) {
             painter->drawText(x+5, y, QStringLiteral("B"));
         }
 
         QPen grapePen = Marble::Oxygen::grapeViolet4;
         grapePen.setWidth ( 2 );
         painter->setPen ( grapePen );
         GeoDataLineString string;
         string << m_cities[0] << a2 << b1 << m_cities[3];
         painter->drawPolyline ( string );
 
         GeoDataCoordinates i1 = m_cities[1].interpolate( m_cities[2], m_fraction-m_delta );
         GeoDataCoordinates i2 = a2.interpolate( b1, m_fraction-m_delta );
         QPen raspberryPen = Marble::Oxygen::burgundyPurple4;
         raspberryPen.setWidth ( 2 );
         painter->setPen ( raspberryPen );
         GeoDataLineString inter;
         inter << i1 << i2;
         painter->drawPolyline ( inter );
     }
 
     // Green linestring shows interpolation path
     QPen greenPen = Marble::Oxygen::forestGreen4;
     greenPen.setWidth ( 3 );
     painter->setPen ( greenPen );
     painter->drawPolyline ( m_interpolated, QStringLiteral("Squad\nInterpolation"), LineEnd );
 
     // Increasing city indices with some transparency effect for readability
     QFont font = painter->font();
     font.setBold( true );
     painter->setFont( font );
     QColor blue = QColor ( Marble::Oxygen::skyBlue4 );
     blue.setAlpha( 150 );
     painter->setBrush ( QBrush ( blue ) );
     int const h = painter->fontMetrics().height();
     for ( int i = 0; i < m_cities.size(); ++i ) {
         qreal x, y;
         QString const text = QString::number ( m_index + i );
         int const w = painter->fontMetrics().width( text );
         painter->setPen ( Qt::NoPen );
         painter->drawEllipse ( m_cities[i], 1.5*w, 1.5*h );
         painter->setPen ( QColor ( Marble::Oxygen::aluminumGray4 ) );
         if ( viewport->screenCoordinates ( m_cities[i], x, y ) ) {
             painter->drawText ( x-w/2, y+h/3, text );
         }
     }
 
     return true;
 }
 
 GeoDataLatLonBox MyPaintLayer::center() const
 {
     GeoDataLinearRing ring;
     foreach( const GeoDataCoordinates &city, m_cities ) {
         ring << city;
     }
     return ring.latLonAltBox();
 }
 
 void MyPaintLayer::addRandomCity ( double minDistance, double maxDistance )
 {
     minDistance *= KM2METER;
     maxDistance *= KM2METER;
     GeoDataTreeModel* tree = m_widget->model()->treeModel();
     if ( !tree || tree->rowCount() < 6 || m_cities.isEmpty() ) {
         return;
     }
 
     // Traverse Marble's internal city database and add a random one
     // which is in the requested distance range to the last one
     for ( int i = 0; i < tree->rowCount(); ++i ) {
         QVariant const data = tree->data ( tree->index ( i, 0 ), MarblePlacemarkModel::ObjectPointerRole );
         GeoDataObject *object = qvariant_cast<GeoDataObject*> ( data );
         Q_ASSERT ( object );
         if (const auto document = geodata_cast<GeoDataDocument>(object)) {
             if (document->name() == QLatin1String("cityplacemarks")) {
                 QVector<GeoDataPlacemark*> placemarks = document->placemarkList();
                 for ( int i = qrand() % placemarks.size(); i < placemarks.size(); ++i ) {
                     const double distance = EARTH_RADIUS * m_cities.last().sphericalDistanceTo(placemarks[i]->coordinate());
                     if ( distance >= minDistance && distance <= maxDistance ) {
                         m_cities << placemarks[i]->coordinate();
                         return;
                     }
                 }
             }
         }
     }
 
     addRandomCity();
 }
 
 GeoDataCoordinates MyPaintLayer::basePoint( const GeoDataCoordinates &c1, const GeoDataCoordinates &c2, const GeoDataCoordinates &c3 )
 {
     Quaternion const a = (c2.quaternion().inverse() * c3.quaternion()).log();
     Quaternion const b = (c2.quaternion().inverse() * c1.quaternion()).log();
     Quaternion const c = c2.quaternion() * ((a+b)*-0.25).exp();
     qreal lon, lat;
     c.getSpherical( lon, lat );
     return GeoDataCoordinates( lon, lat );
 }
 
 void MyPaintLayer::addInterpolatedPoint()
 {
     while ( m_interpolated.size() > 2.0/m_delta ) {
         m_interpolated.remove ( 0 );
     }
 
     m_delta = m_index < 20 ? 0.01 : 0.04;
     Q_ASSERT ( m_cities.size() == 4 );
     // Interpolate for the current city
     m_interpolated << m_cities[1].interpolate ( m_cities[0], m_cities[2], m_cities[3], m_fraction );
     m_fraction += m_delta;
 
     // If current city is done, move one forward
     if ( m_fraction > 1.0 ) {
         m_fraction = 0.0;
         m_cities.remove ( 0 );
         addRandomCity();
         ++m_index;
     }
 
     // Repaint map, recenter if out of view
     bool hidden;
     qreal x; qreal y;
     if ( m_widget->viewport()->screenCoordinates ( m_interpolated.last(), x, y, hidden ) ) {
         m_widget->update();
     } else {
         m_widget->centerOn ( center() );
     }
 
     int const timeout = qBound( 0, 150 - 50 * m_index, 150 );
     QTimer::singleShot ( timeout, this, SLOT (addInterpolatedPoint()) );
 }
 
 }
 
 int main ( int argc, char** argv )
 {
     using namespace Marble;
     QApplication app ( argc, argv );
     MarbleWidget *mapWidget = new MarbleWidget;
     mapWidget->setWindowTitle(QStringLiteral("Marble - Squad Interpolation"));
 
     // Create and register our paint layer
     MyPaintLayer* layer = new MyPaintLayer ( mapWidget );
     mapWidget->addLayer ( layer );
     mapWidget->centerOn ( layer->center() );
 
     // Finish widget creation.
     mapWidget->setMapThemeId(QStringLiteral("earth/plain/plain.dgml"));
     mapWidget->setShowCities( false );
     mapWidget->setShowCrosshairs( false );
     mapWidget->setShowOtherPlaces( false );
     mapWidget->setShowPlaces( false );
     mapWidget->setShowTerrain( false );
     mapWidget->show();
 
     return app.exec();
 }
 
 #include "moc_squad-interpolation.cpp"