GeoDataLatLonAltBox EquirectProjection::latLonAltBox( const QRect& screenRect,
const ViewportParams *viewport ) const
{
qreal west;
qreal north = 90*DEG2RAD;
geoCoordinates( screenRect.left(), screenRect.top(), viewport, west, north, GeoDataCoordinates::Radian );
qreal east;
qreal south = -90*DEG2RAD;
geoCoordinates( screenRect.right(), screenRect.bottom(), viewport, east, south, GeoDataCoordinates::Radian );
// For the case where the whole viewport gets covered there is a
// pretty dirty and generic detection algorithm:
GeoDataLatLonAltBox latLonAltBox;
latLonAltBox.setNorth( north, GeoDataCoordinates::Radian );
latLonAltBox.setSouth( south, GeoDataCoordinates::Radian );
latLonAltBox.setWest( west, GeoDataCoordinates::Radian );
latLonAltBox.setEast( east, GeoDataCoordinates::Radian );
latLonAltBox.setMinAltitude( -100000000.0 );
latLonAltBox.setMaxAltitude( 100000000000000.0 );
// Convenience variables
int radius = viewport->radius();
int width = viewport->width();
// The remaining algorithm should be pretty generic for all kinds of
// flat projections:
int xRepeatDistance = 4 * radius;
if ( width >= xRepeatDistance ) {
latLonAltBox.setWest( -M_PI );
latLonAltBox.setEast( +M_PI );
}
// Now we need to check whether maxLat (e.g. the north pole) gets displayed
// inside the viewport.
// We need a point on the screen at maxLat that definitely gets displayed:
qreal averageLongitude = latLonAltBox.east();
GeoDataCoordinates maxLatPoint( averageLongitude, maxLat(), 0.0, GeoDataCoordinates::Radian );
GeoDataCoordinates minLatPoint( averageLongitude, minLat(), 0.0, GeoDataCoordinates::Radian );
qreal dummyX, dummyY; // not needed
if ( screenCoordinates( maxLatPoint, viewport, dummyX, dummyY ) ) {
latLonAltBox.setEast( +M_PI );
latLonAltBox.setWest( -M_PI );
}
if ( screenCoordinates( minLatPoint, viewport, dummyX, dummyY ) ) {
latLonAltBox.setEast( +M_PI );
latLonAltBox.setWest( -M_PI );
}
return latLonAltBox;
}
void TestGeoDataLatLonAltBox::testAltitude()
{
QFETCH(qreal, alt);
GeoDataLatLonAltBox box;
box.setMinAltitude(alt);
QCOMPARE(box.minAltitude(), alt);
box.setMaxAltitude(alt);
QCOMPARE(box.maxAltitude(), alt);
}
GeoDataLatLonAltBox GeoDataLatLonAltBox::fromLineString( const GeoDataLineString& lineString )
{
// If the line string is empty return a boundingbox that contains everything
if ( lineString.size() == 0 ) {
return GeoDataLatLonAltBox();
}
const qreal altitude = lineString.first().altitude();
GeoDataLatLonAltBox temp ( GeoDataLatLonBox::fromLineString( lineString ), altitude, altitude );
qreal maxAltitude = altitude;
qreal minAltitude = altitude;
// If there's only a single node stored then the boundingbox only contains that point
if ( lineString.size() == 1 ) {
temp.setMinAltitude( minAltitude );
temp.setMaxAltitude( maxAltitude );
return temp;
}
QVector<GeoDataCoordinates>::ConstIterator it( lineString.constBegin() );
QVector<GeoDataCoordinates>::ConstIterator itEnd( lineString.constEnd() );
for ( ; it != itEnd; ++it )
{
// Get coordinates and normalize them to the desired range.
const qreal altitude = (it)->altitude();
// Determining the maximum and minimum latitude
if ( altitude > maxAltitude ) maxAltitude = altitude;
if ( altitude < minAltitude ) minAltitude = altitude;
}
temp.setMinAltitude( minAltitude );
temp.setMaxAltitude( maxAltitude );
return temp;
}
