void GeoDataLineStringPrivate::toPoleCorrected( const GeoDataLineString& q, GeoDataLineString& poleCorrected )
{
poleCorrected.setTessellationFlags( q.tessellationFlags() );
GeoDataCoordinates previousCoords;
GeoDataCoordinates currentCoords;
if ( q.isClosed() ) {
if ( !( m_vector.first().isPole() ) &&
( m_vector.last().isPole() ) ) {
qreal firstLongitude = ( m_vector.first() ).longitude();
GeoDataCoordinates modifiedCoords( m_vector.last() );
modifiedCoords.setLongitude( firstLongitude );
poleCorrected << modifiedCoords;
}
}
QVector<GeoDataCoordinates>::const_iterator itCoords = m_vector.constBegin();
QVector<GeoDataCoordinates>::const_iterator itEnd = m_vector.constEnd();
for( ; itCoords != itEnd; ++itCoords ) {
currentCoords = *itCoords;
if ( itCoords == m_vector.constBegin() ) {
previousCoords = currentCoords;
}
if ( currentCoords.isPole() ) {
if ( previousCoords.isPole() ) {
continue;
}
else {
qreal previousLongitude = previousCoords.longitude();
GeoDataCoordinates currentModifiedCoords( currentCoords );
currentModifiedCoords.setLongitude( previousLongitude );
poleCorrected << currentModifiedCoords;
}
}
else {
if ( previousCoords.isPole() ) {
qreal currentLongitude = currentCoords.longitude();
GeoDataCoordinates previousModifiedCoords( previousCoords );
previousModifiedCoords.setLongitude( currentLongitude );
poleCorrected << previousModifiedCoords;
poleCorrected << currentCoords;
}
else {
// No poles at all. Nothing special to handle
poleCorrected << currentCoords;
}
}
previousCoords = currentCoords;
}
if ( q.isClosed() ) {
if ( ( m_vector.first().isPole() ) &&
!( m_vector.last().isPole() ) ) {
qreal lastLongitude = ( m_vector.last() ).longitude();
GeoDataCoordinates modifiedCoords( m_vector.first() );
modifiedCoords.setLongitude( lastLongitude );
poleCorrected << modifiedCoords;
}
}
}
int CylindricalProjectionPrivate::processTessellation( const GeoDataCoordinates &previousCoords,
const GeoDataCoordinates ¤tCoords,
int tessellatedNodes,
QVector<QPolygonF*> &polygons,
const ViewportParams *viewport,
TessellationFlags f,
int mirrorCount,
qreal repeatDistance) const
{
const bool clampToGround = f.testFlag( FollowGround );
const bool followLatitudeCircle = f.testFlag( RespectLatitudeCircle )
&& previousCoords.latitude() == currentCoords.latitude();
// Calculate steps for tessellation: lonDiff and altDiff
qreal lonDiff = 0.0;
if ( followLatitudeCircle ) {
const int previousSign = previousCoords.longitude() > 0 ? 1 : -1;
const int currentSign = currentCoords.longitude() > 0 ? 1 : -1;
lonDiff = currentCoords.longitude() - previousCoords.longitude();
if ( previousSign != currentSign
&& fabs(previousCoords.longitude()) + fabs(currentCoords.longitude()) > M_PI ) {
if ( previousSign > currentSign ) {
// going eastwards ->
lonDiff += 2 * M_PI ;
} else {
// going westwards ->
lonDiff -= 2 * M_PI;
}
}
if ( fabs( lonDiff ) == 2 * M_PI ) {
return mirrorCount;
}
}
const qreal altDiff = currentCoords.altitude() - previousCoords.altitude();
// Create the tessellation nodes.
GeoDataCoordinates previousTessellatedCoords = previousCoords;
for ( int i = 1; i <= tessellatedNodes; ++i ) {
const qreal t = (qreal)(i) / (qreal)( tessellatedNodes + 1 );
// interpolate the altitude, too
const qreal altitude = clampToGround ? 0 : altDiff * t + previousCoords.altitude();
qreal lon = 0.0;
qreal lat = 0.0;
if ( followLatitudeCircle ) {
// To tessellate along latitude circles use the
// linear interpolation of the longitude.
lon = lonDiff * t + previousCoords.longitude();
lat = previousTessellatedCoords.latitude();
}
else {
// To tessellate along great circles use the
// normalized linear interpolation ("NLERP") for latitude and longitude.
const Quaternion itpos = Quaternion::nlerp( previousCoords.quaternion(), currentCoords.quaternion(), t );
itpos. getSpherical( lon, lat );
}
const GeoDataCoordinates currentTessellatedCoords( lon, lat, altitude );
Q_Q(const CylindricalProjection);
qreal bx, by;
q->screenCoordinates( currentTessellatedCoords, viewport, bx, by );
mirrorCount = crossDateLine( previousTessellatedCoords, currentTessellatedCoords, bx, by, polygons,
mirrorCount, repeatDistance );
previousTessellatedCoords = currentTessellatedCoords;
}
// For the clampToGround case add the "current" coordinate after adding all other nodes.
GeoDataCoordinates currentModifiedCoords( currentCoords );
if ( clampToGround ) {
currentModifiedCoords.setAltitude( 0.0 );
}
Q_Q(const CylindricalProjection);
qreal bx, by;
q->screenCoordinates( currentModifiedCoords, viewport, bx, by );
mirrorCount = crossDateLine( previousTessellatedCoords, currentModifiedCoords, bx, by, polygons,
mirrorCount, repeatDistance );
return mirrorCount;
}
