void TestQgsCoordinateTransform::assignment()
{
QgsCoordinateTransform uninitialized;
QgsCoordinateTransform uninitializedCopy;
uninitializedCopy = uninitialized;
QVERIFY( !uninitializedCopy.isValid() );
QgsCoordinateReferenceSystem source;
source.createFromId( 3111, QgsCoordinateReferenceSystem::EpsgCrsId );
QgsCoordinateReferenceSystem destination;
destination.createFromId( 4326, QgsCoordinateReferenceSystem::EpsgCrsId );
QgsCoordinateTransform original( source, destination );
QVERIFY( original.isValid() );
QgsCoordinateTransform copy;
copy = original;
QVERIFY( copy.isValid() );
QCOMPARE( copy.sourceCrs().authid(), original.sourceCrs().authid() );
QCOMPARE( copy.destinationCrs().authid(), original.destinationCrs().authid() );
// force detachement of copy
QgsCoordinateReferenceSystem newDest;
newDest.createFromId( 3857, QgsCoordinateReferenceSystem::EpsgCrsId );
copy.setDestinationCrs( newDest );
QVERIFY( copy.isValid() );
QCOMPARE( copy.destinationCrs().authid(), QString( "EPSG:3857" ) );
QCOMPARE( original.destinationCrs().authid(), QString( "EPSG:4326" ) );
// test assigning back to invalid
copy = uninitialized;
QVERIFY( !copy.isValid() );
QVERIFY( original.isValid() );
}
QgsRectangle QgsMapSettings::outputExtentToLayerExtent( const QgsMapLayer *layer, QgsRectangle extent ) const
{
try
{
QgsCoordinateTransform ct = layerTransform( layer );
if ( ct.isValid() )
{
QgsDebugMsgLevel( QStringLiteral( "sourceCrs = %1" ).arg( ct.sourceCrs().authid() ), 3 );
QgsDebugMsgLevel( QStringLiteral( "destCRS = %1" ).arg( ct.destinationCrs().authid() ), 3 );
QgsDebugMsgLevel( QStringLiteral( "extent = %1" ).arg( extent.toString() ), 3 );
extent = ct.transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );
}
}
catch ( QgsCsException &cse )
{
QgsMessageLog::logMessage( QObject::tr( "Transform error caught: %1" ).arg( cse.what() ), QObject::tr( "CRS" ) );
}
QgsDebugMsgLevel( QStringLiteral( "proj extent = %1" ).arg( extent.toString() ), 3 );
return extent;
}
bool QgsMapRendererJob::reprojectToLayerExtent( const QgsMapLayer *ml, const QgsCoordinateTransform &ct, QgsRectangle &extent, QgsRectangle &r2 )
{
bool split = false;
try
{
#ifdef QGISDEBUG
// QgsLogger::debug<QgsRectangle>("Getting extent of canvas in layers CS. Canvas is ", extent, __FILE__, __FUNCTION__, __LINE__);
#endif
// Split the extent into two if the source CRS is
// geographic and the extent crosses the split in
// geographic coordinates (usually +/- 180 degrees,
// and is assumed to be so here), and draw each
// extent separately.
static const double SPLIT_COORD = 180.0;
if ( ml->crs().isGeographic() )
{
if ( ml->type() == QgsMapLayer::VectorLayer && !ct.destinationCrs().isGeographic() )
{
// if we transform from a projected coordinate system check
// check if transforming back roughly returns the input
// extend - otherwise render the world.
QgsRectangle extent1 = ct.transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );
QgsRectangle extent2 = ct.transformBoundingBox( extent1, QgsCoordinateTransform::ForwardTransform );
QgsDebugMsgLevel( QString( "\n0:%1 %2x%3\n1:%4\n2:%5 %6x%7 (w:%8 h:%9)" )
.arg( extent.toString() ).arg( extent.width() ).arg( extent.height() )
.arg( extent1.toString(), extent2.toString() ).arg( extent2.width() ).arg( extent2.height() )
.arg( std::fabs( 1.0 - extent2.width() / extent.width() ) )
.arg( std::fabs( 1.0 - extent2.height() / extent.height() ) )
, 3 );
if ( std::fabs( 1.0 - extent2.width() / extent.width() ) < 0.5 &&
std::fabs( 1.0 - extent2.height() / extent.height() ) < 0.5 )
{
extent = extent1;
}
else
{
extent = QgsRectangle( -180.0, -90.0, 180.0, 90.0 );
}
}
else
{
// Note: ll = lower left point
QgsPointXY ll = ct.transform( extent.xMinimum(), extent.yMinimum(),
QgsCoordinateTransform::ReverseTransform );
// and ur = upper right point
QgsPointXY ur = ct.transform( extent.xMaximum(), extent.yMaximum(),
QgsCoordinateTransform::ReverseTransform );
QgsDebugMsgLevel( QString( "in:%1 (ll:%2 ur:%3)" ).arg( extent.toString(), ll.toString(), ur.toString() ), 4 );
extent = ct.transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );
QgsDebugMsgLevel( QString( "out:%1 (w:%2 h:%3)" ).arg( extent.toString() ).arg( extent.width() ).arg( extent.height() ), 4 );
if ( ll.x() > ur.x() )
{
// the coordinates projected in reverse order than what one would expect.
// we are probably looking at an area that includes longitude of 180 degrees.
// we need to take into account coordinates from two intervals: (-180,x1) and (x2,180)
// so let's use (-180,180). This hopefully does not add too much overhead. It is
// more straightforward than rendering with two separate extents and more consistent
// for rendering, labeling and caching as everything is rendered just in one go
extent.setXMinimum( -SPLIT_COORD );
extent.setXMaximum( SPLIT_COORD );
}
}
// TODO: the above rule still does not help if using a projection that covers the whole
// world. E.g. with EPSG:3857 the longitude spectrum -180 to +180 is mapped to approx.
// -2e7 to +2e7. Converting extent from -5e7 to +5e7 is transformed as -90 to +90,
// but in fact the extent should cover the whole world.
}
else // can't cross 180
{
if ( ct.destinationCrs().isGeographic() &&
( extent.xMinimum() <= -180 || extent.xMaximum() >= 180 ||
extent.yMinimum() <= -90 || extent.yMaximum() >= 90 ) )
// Use unlimited rectangle because otherwise we may end up transforming wrong coordinates.
// E.g. longitude -200 to +160 would be understood as +40 to +160 due to periodicity.
// We could try to clamp coords to (-180,180) for lon resp. (-90,90) for lat,
// but this seems like a safer choice.
extent = QgsRectangle( -DBL_MAX, -DBL_MAX, DBL_MAX, DBL_MAX );
else
extent = ct.transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );
}
}
catch ( QgsCsException &cse )
{
Q_UNUSED( cse );
QgsDebugMsg( "Transform error caught" );
extent = QgsRectangle( -DBL_MAX, -DBL_MAX, DBL_MAX, DBL_MAX );
r2 = QgsRectangle( -DBL_MAX, -DBL_MAX, DBL_MAX, DBL_MAX );
}
return split;
}
