bool QgsMapToolIdentify::identifyRasterLayer( QList<IdentifyResult> *results, QgsRasterLayer *layer, QgsPoint point, QgsRectangle viewExtent, double mapUnitsPerPixel )
{
  QgsDebugMsg( "point = " + point.toString() );
  if ( !layer ) return false;

  QgsRasterDataProvider *dprovider = layer->dataProvider();
  int capabilities = dprovider->capabilities();
  if ( !dprovider || !( capabilities & QgsRasterDataProvider::Identify ) )
  {
    return false;
  }

  try
  {
    point = toLayerCoordinates( layer, point );
  }
  catch ( QgsCsException &cse )
  {
    Q_UNUSED( cse );
    QgsDebugMsg( QString( "coordinate not reprojectable: %1" ).arg( cse.what() ) );
    return false;
  }
  QgsDebugMsg( QString( "point = %1 %2" ).arg( point.x() ).arg( point.y() ) );

  if ( !layer->extent().contains( point ) ) return false;

  QMap< QString, QString > attributes, derivedAttributes;

  QMap<int, QVariant> values;

  QgsRasterDataProvider::IdentifyFormat format = QgsRasterDataProvider::identifyFormatFromName( layer->customProperty( "identify/format" ).toString() );

  // check if the format is really supported otherwise use first supported format
  if ( !( QgsRasterDataProvider::identifyFormatToCapability( format ) & capabilities ) )
  {
    if ( capabilities & QgsRasterInterface::IdentifyFeature ) format = QgsRasterDataProvider::IdentifyFormatFeature;
    else if ( capabilities & QgsRasterInterface::IdentifyValue ) format = QgsRasterDataProvider::IdentifyFormatValue;
    else if ( capabilities & QgsRasterInterface::IdentifyHtml ) format = QgsRasterDataProvider::IdentifyFormatHtml;
    else if ( capabilities & QgsRasterInterface::IdentifyText ) format = QgsRasterDataProvider::IdentifyFormatText;
    else return false;
  }

  // We can only use context (extent, width, heigh) if layer is not reprojected,
  // otherwise we don't know source resolution (size).
  if ( mCanvas->hasCrsTransformEnabled() && dprovider->crs() != mCanvas->mapRenderer()->destinationCrs() )
  {
    viewExtent = toLayerCoordinates( layer, viewExtent );
    values = dprovider->identify( point, format );
  }
  else
  {
    // It would be nice to use the same extent and size which was used for drawing,
    // so that WCS can use cache from last draw, unfortunately QgsRasterLayer::draw()
    // is doing some tricks with extent and size to allign raster to output which
    // would be difficult to replicate here.
    // Note: cutting the extent may result in slightly different x and y resolutions
    // and thus shifted point calculated back in QGIS WMS (using average resolution)
    //viewExtent = dprovider->extent().intersect( &viewExtent );

    // Width and height are calculated from not projected extent and we hope that
    // are similar to source width and height used to reproject layer for drawing.
    // TODO: may be very dangerous, because it may result in different resolutions
    // in source CRS, and WMS server (QGIS server) calcs wrong coor using average resolution.
    int width = qRound( viewExtent.width() / mapUnitsPerPixel );
    int height = qRound( viewExtent.height() / mapUnitsPerPixel );

    QgsDebugMsg( QString( "viewExtent.width = %1 viewExtent.height = %2" ).arg( viewExtent.width() ).arg( viewExtent.height() ) );
    QgsDebugMsg( QString( "width = %1 height = %2" ).arg( width ).arg( height ) );
    QgsDebugMsg( QString( "xRes = %1 yRes = %2 mapUnitsPerPixel = %3" ).arg( viewExtent.width() / width ).arg( viewExtent.height() / height ).arg( mapUnitsPerPixel ) );

    values = dprovider->identify( point, format, viewExtent, width, height );
  }

  derivedAttributes.insert( tr( "(clicked coordinate)" ), point.toString() );

  //QString type = tr( "Raster" );
  QgsGeometry geometry;
  if ( format == QgsRasterDataProvider::IdentifyFormatValue )
  {
    foreach ( int bandNo, values.keys() )
    {
      double value = values.value( bandNo ).toDouble();
      QString valueString;
      if ( dprovider->isNoDataValue( bandNo, value ) )
      {
        valueString = tr( "no data" );
      }
      else
      {
        valueString = QgsRasterBlock::printValue( value );
      }
      attributes.insert( dprovider->generateBandName( bandNo ), valueString );
    }
    QString label = layer->name();
    results->append( IdentifyResult( qobject_cast<QgsMapLayer *>( layer ), label, attributes, derivedAttributes ) );
  }
Пример #2
0
QPointF QgsMapCanvasItem::toCanvasCoordinates( const QgsPoint& point )
{
  double x = point.x(), y = point.y();
  mMapCanvas->getCoordinateTransform()->transformInPlace( x, y );
  return QPointF( x, y ) + mPanningOffset;
}
Пример #3
0
QVariantMap QgsJoinWithLinesAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  if ( parameters.value( QStringLiteral( "SPOKES" ) ) == parameters.value( QStringLiteral( "HUBS" ) ) )
    throw QgsProcessingException( QObject::tr( "Same layer given for both hubs and spokes" ) );

  std::unique_ptr< QgsFeatureSource > hubSource( parameterAsSource( parameters, QStringLiteral( "HUBS" ), context ) );
  std::unique_ptr< QgsFeatureSource > spokeSource( parameterAsSource( parameters, QStringLiteral( "SPOKES" ), context ) );
  if ( !hubSource || !spokeSource )
    return QVariantMap();

  QString fieldHubName = parameterAsString( parameters, QStringLiteral( "HUB_FIELD" ), context );
  int fieldHubIndex = hubSource->fields().lookupField( fieldHubName );
  const QStringList hubFieldsToCopy = parameterAsFields( parameters, QStringLiteral( "HUB_FIELDS" ), context );

  QString fieldSpokeName = parameterAsString( parameters, QStringLiteral( "SPOKE_FIELD" ), context );
  int fieldSpokeIndex = spokeSource->fields().lookupField( fieldSpokeName );
  const QStringList spokeFieldsToCopy = parameterAsFields( parameters, QStringLiteral( "SPOKE_FIELDS" ), context );

  if ( fieldHubIndex < 0 || fieldSpokeIndex < 0 )
    throw QgsProcessingException( QObject::tr( "Invalid ID field" ) );

  QgsFields hubOutFields;
  QgsAttributeList hubFieldIndices;
  if ( hubFieldsToCopy.empty() )
  {
    hubOutFields = hubSource->fields();
    for ( int i = 0; i < hubOutFields.count(); ++i )
    {
      hubFieldIndices << i;
    }
  }
  else
  {
    for ( const QString &field : hubFieldsToCopy )
    {
      int index = hubSource->fields().lookupField( field );
      if ( index >= 0 )
      {
        hubFieldIndices << index;
        hubOutFields.append( hubSource->fields().at( index ) );
      }
    }
  }

  QgsAttributeList hubFields2Fetch = hubFieldIndices;
  hubFields2Fetch << fieldHubIndex;

  QgsFields spokeOutFields;
  QgsAttributeList spokeFieldIndices;
  if ( spokeFieldsToCopy.empty() )
  {
    spokeOutFields = spokeSource->fields();
    for ( int i = 0; i < spokeOutFields.count(); ++i )
    {
      spokeFieldIndices << i;
    }
  }
  else
  {
    for ( const QString &field : spokeFieldsToCopy )
    {
      int index = spokeSource->fields().lookupField( field );
      if ( index >= 0 )
      {
        spokeFieldIndices << index;
        spokeOutFields.append( spokeSource->fields().at( index ) );
      }
    }
  }

  QgsAttributeList spokeFields2Fetch = spokeFieldIndices;
  spokeFields2Fetch << fieldSpokeIndex;


  QgsFields fields = QgsProcessingUtils::combineFields( hubOutFields, spokeOutFields );

  QgsWkbTypes::Type outType = QgsWkbTypes::LineString;
  bool hasZ = false;
  if ( QgsWkbTypes::hasZ( hubSource->wkbType() ) || QgsWkbTypes::hasZ( spokeSource->wkbType() ) )
  {
    outType = QgsWkbTypes::addZ( outType );
    hasZ = true;
  }
  bool hasM = false;
  if ( QgsWkbTypes::hasM( hubSource->wkbType() ) || QgsWkbTypes::hasM( spokeSource->wkbType() ) )
  {
    outType = QgsWkbTypes::addM( outType );
    hasM = true;
  }

  QString dest;
  std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, fields,
                                          outType, hubSource->sourceCrs() ) );
  if ( !sink )
    return QVariantMap();

  auto getPointFromFeature = [hasZ, hasM]( const QgsFeature & feature )->QgsPoint
  {
    QgsPoint p;
    if ( feature.geometry().type() == QgsWkbTypes::PointGeometry && !feature.geometry().isMultipart() )
      p = *static_cast< const QgsPoint *>( feature.geometry().constGet() );
    else
      p = *static_cast< const QgsPoint *>( feature.geometry().pointOnSurface().constGet() );
    if ( hasZ && !p.is3D() )
      p.addZValue( 0 );
    if ( hasM && !p.isMeasure() )
      p.addMValue( 0 );
    return p;
  };

  QgsFeatureIterator hubFeatures = hubSource->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( hubFields2Fetch ) );
  double step = hubSource->featureCount() > 0 ? 100.0 / hubSource->featureCount() : 1;
  int i = 0;
  QgsFeature hubFeature;
  while ( hubFeatures.nextFeature( hubFeature ) )
  {
    i++;
    if ( feedback->isCanceled() )
    {
      break;
    }

    feedback->setProgress( i * step );

    if ( !hubFeature.hasGeometry() )
      continue;

    QgsPoint hubPoint = getPointFromFeature( hubFeature );

    // only keep selected attributes
    QgsAttributes hubAttributes;
    for ( int j = 0; j < hubFeature.attributes().count(); ++j )
    {
      if ( !hubFieldIndices.contains( j ) )
        continue;
      hubAttributes << hubFeature.attribute( j );
    }

    QgsFeatureRequest spokeRequest = QgsFeatureRequest().setDestinationCrs( hubSource->sourceCrs(), context.transformContext() );
    spokeRequest.setSubsetOfAttributes( spokeFields2Fetch );
    spokeRequest.setFilterExpression( QgsExpression::createFieldEqualityExpression( fieldSpokeName, hubFeature.attribute( fieldHubIndex ) ) );

    QgsFeatureIterator spokeFeatures = spokeSource->getFeatures( spokeRequest );
    QgsFeature spokeFeature;
    while ( spokeFeatures.nextFeature( spokeFeature ) )
    {
      if ( feedback->isCanceled() )
      {
        break;
      }
      if ( !spokeFeature.hasGeometry() )
        continue;

      QgsPoint spokePoint = getPointFromFeature( spokeFeature );
      QgsGeometry line( new QgsLineString( QVector< QgsPoint >() << hubPoint << spokePoint ) );

      QgsFeature outFeature;
      QgsAttributes outAttributes = hubAttributes;

      // only keep selected attributes
      QgsAttributes spokeAttributes;
      for ( int j = 0; j < spokeFeature.attributes().count(); ++j )
      {
        if ( !spokeFieldIndices.contains( j ) )
          continue;
        spokeAttributes << spokeFeature.attribute( j );
      }

      outAttributes.append( spokeAttributes );
      outFeature.setAttributes( outAttributes );
      outFeature.setGeometry( line );
      sink->addFeature( outFeature, QgsFeatureSink::FastInsert );
    }
  }

  QVariantMap outputs;
  outputs.insert( QStringLiteral( "OUTPUT" ), dest );
  return outputs;
}
Пример #4
0
// Default implementation for values
QgsRasterIdentifyResult QgsRasterDataProvider::identify( const QgsPoint & thePoint, QgsRaster::IdentifyFormat theFormat, const QgsRectangle &theExtent, int theWidth, int theHeight )
{
  QgsDebugMsg( "Entered" );
  QMap<int, QVariant> results;

  if ( theFormat != QgsRaster::IdentifyFormatValue || !( capabilities() & IdentifyValue ) )
  {
    QgsDebugMsg( "Format not supported" );
    return QgsRasterIdentifyResult( ERR( tr( "Format not supported" ) ) );
  }

  if ( !extent().contains( thePoint ) )
  {
    // Outside the raster
    for ( int bandNo = 1; bandNo <= bandCount(); bandNo++ )
    {
      results.insert( bandNo, QVariant() );
    }
    return QgsRasterIdentifyResult( QgsRaster::IdentifyFormatValue, results );
  }

  QgsRectangle myExtent = theExtent;
  if ( myExtent.isEmpty() )  myExtent = extent();

  if ( theWidth == 0 )
  {
    theWidth = capabilities() & Size ? xSize() : 1000;
  }
  if ( theHeight == 0 )
  {
    theHeight = capabilities() & Size ? ySize() : 1000;
  }

  // Calculate the row / column where the point falls
  double xres = ( myExtent.width() ) / theWidth;
  double yres = ( myExtent.height() ) / theHeight;

  int col = ( int ) floor(( thePoint.x() - myExtent.xMinimum() ) / xres );
  int row = ( int ) floor(( myExtent.yMaximum() - thePoint.y() ) / yres );

  double xMin = myExtent.xMinimum() + col * xres;
  double xMax = xMin + xres;
  double yMax = myExtent.yMaximum() - row * yres;
  double yMin = yMax - yres;
  QgsRectangle pixelExtent( xMin, yMin, xMax, yMax );

  for ( int i = 1; i <= bandCount(); i++ )
  {
    QgsRasterBlock * myBlock = block( i, pixelExtent, 1, 1 );

    if ( myBlock )
    {
      double value = myBlock->value( 0 );

      results.insert( i, value );
      delete myBlock;
    }
    else
    {
      results.insert( i, QVariant() );
    }
  }
  return QgsRasterIdentifyResult( QgsRaster::IdentifyFormatValue, results );
}
Пример #5
0
void QgsMapMouseEvent::setPoint( const QgsPoint& point )
{
    mMapPoint.set( point.x(), point.y() );
}
void QgsMapToolMoveFeature::canvasPressEvent( QMouseEvent * e )
{
  delete mRubberBand;
  mRubberBand = 0;

  QgsVectorLayer* vlayer = currentVectorLayer();
  if ( !vlayer )
  {
    notifyNotVectorLayer();
    return;
  }

  if ( !vlayer->isEditable() )
  {
    notifyNotEditableLayer();
    return;
  }

  //find first geometry under mouse cursor and store iterator to it
  QgsPoint layerCoords = toLayerCoordinates( vlayer, e->pos() );
  QSettings settings;
  double searchRadius = QgsTolerance::vertexSearchRadius( mCanvas->currentLayer(), mCanvas->mapRenderer() );
  QgsRectangle selectRect( layerCoords.x() - searchRadius, layerCoords.y() - searchRadius,
                           layerCoords.x() + searchRadius, layerCoords.y() + searchRadius );

  if ( vlayer->selectedFeatureCount() == 0 )
  {
    QgsFeatureIterator fit = vlayer->getFeatures( QgsFeatureRequest().setFilterRect( selectRect ).setSubsetOfAttributes( QgsAttributeList() ) );

    //find the closest feature
    QgsGeometry* pointGeometry = QgsGeometry::fromPoint( layerCoords );
    if ( !pointGeometry )
    {
      return;
    }

    double minDistance = std::numeric_limits<double>::max();

    QgsFeature cf;
    QgsFeature f;
    while ( fit.nextFeature( f ) )
    {
      if ( f.geometry() )
      {
        double currentDistance = pointGeometry->distance( *f.geometry() );
        if ( currentDistance < minDistance )
        {
          minDistance = currentDistance;
          cf = f;
        }
      }

    }

    delete pointGeometry;

    if ( minDistance == std::numeric_limits<double>::max() )
    {
      return;
    }

    mMovedFeatures.clear();
    mMovedFeatures << cf.id(); //todo: take the closest feature, not the first one...

    mRubberBand = createRubberBand( vlayer->geometryType() );
    mRubberBand->setToGeometry( cf.geometry(), vlayer );
  }
  else
  {
    mMovedFeatures = vlayer->selectedFeaturesIds();

    mRubberBand = createRubberBand( vlayer->geometryType() );
    for ( int i = 0; i < vlayer->selectedFeatureCount(); i++ )
    {
      mRubberBand->addGeometry( vlayer->selectedFeatures()[i].geometry(), vlayer );
    }
  }

  mStartPointMapCoords = toMapCoordinates( e->pos() );
  mRubberBand->setColor( QColor( 255, 0, 0, 65 ) );
  mRubberBand->setWidth( 2 );
  mRubberBand->show();

}
Пример #7
0
bool QgsMapToolIdentify::identifyRasterLayer( QgsRasterLayer *layer, int x, int y )
{
  bool res = true;

  if ( !layer )
    return false;

  QgsRasterDataProvider *dprovider = layer->dataProvider();
  if ( dprovider && ( dprovider->capabilities() & QgsRasterDataProvider::Identify ) == 0 )
    return false;

  QMap< QString, QString > attributes, derivedAttributes;
  QgsPoint idPoint = mCanvas->getCoordinateTransform()->toMapCoordinates( x, y );
  try
  {
    idPoint = toLayerCoordinates( layer, idPoint );
  }
  catch ( QgsCsException &cse )
  {
    Q_UNUSED( cse );
    QgsDebugMsg( QString( "coordinate not reprojectable: %1" ).arg( cse.what() ) );
    return false;
  }

  QString type;

  if ( layer->providerType() == "wms" )
  {
    type = tr( "WMS layer" );

    //if WMS layer does not cover the view origin,
    //we need to map the view pixel coordinates
    //to WMS layer pixel coordinates
    QgsRectangle viewExtent = toLayerCoordinates( layer, mCanvas->extent() );
    QgsRectangle layerExtent = layer->extent();
    double mapUnitsPerPixel = mCanvas->mapUnitsPerPixel();
    if ( mapUnitsPerPixel > 0 && viewExtent.intersects( layerExtent ) )
    {
      double xMinView = viewExtent.xMinimum();
      double yMaxView = viewExtent.yMaximum();
      double xMinLayer = layerExtent.xMinimum();
      double yMaxLayer = layerExtent.yMaximum();

      idPoint.set(
        xMinView < xMinLayer ? floor( x - ( xMinLayer - xMinView ) / mapUnitsPerPixel ) : x,
        yMaxView > yMaxLayer ? floor( y - ( yMaxView - yMaxLayer ) / mapUnitsPerPixel ) : y
      );

      attributes.insert( tr( "Feature info" ), layer->identifyAsHtml( idPoint ) );
    }
    else
    {
      res = false;
    }
  }
  else
  {
    type = tr( "Raster" );
    res = layer->extent().contains( idPoint ) && layer->identify( idPoint, attributes );
  }

  if ( res )
  {
    derivedAttributes.insert( tr( "(clicked coordinate)" ), idPoint.toString() );
    results()->addFeature( layer, type, attributes, derivedAttributes );
  }

  return res;
}
Пример #8
0
double QgsPoint::sqrDist( const QgsPoint& other ) const
{
  return sqrDist( other.x(), other.y() );
}
Пример #9
0
double QgsPoint::azimuth( const QgsPoint& other )
{
  double dx = other.x() - m_x;
  double dy = other.y() - m_y;
  return ( atan2( dx, dy ) * 180.0 / M_PI );
}
Пример #10
0
bool QgsTransectSample::closestSegmentPoints( QgsGeometry& g1, QgsGeometry& g2, double& dist, QgsPoint& pt1, QgsPoint& pt2 )
{
  QGis::WkbType t1 = g1.wkbType();
  if ( t1 != QGis::WKBLineString && t1 != QGis::WKBLineString25D )
  {
    return false;
  }

  QGis::WkbType t2 = g2.wkbType();
  if ( t2 != QGis::WKBLineString && t2 != QGis::WKBLineString25D )
  {
    return false;
  }

  QgsPolyline pl1 = g1.asPolyline();
  QgsPolyline pl2 = g2.asPolyline();

  if ( pl1.size() < 2 || pl2.size() < 2 )
  {
    return false;
  }

  QgsPoint p11 = pl1.at( 0 );
  QgsPoint p12 = pl1.at( 1 );
  QgsPoint p21 = pl2.at( 0 );
  QgsPoint p22 = pl2.at( 1 );

  double p1x = p11.x();
  double p1y = p11.y();
  double v1x = p12.x() - p11.x();
  double v1y = p12.y() - p11.y();
  double p2x = p21.x();
  double p2y = p21.y();
  double v2x = p22.x() - p21.x();
  double v2y = p22.y() - p21.y();

  double denominatorU = v2x * v1y - v2y * v1x;
  double denominatorT = v1x * v2y - v1y * v2x;

  if ( qgsDoubleNear( denominatorU, 0 ) || qgsDoubleNear( denominatorT, 0 ) )
  {
    //lines are parallel
    //project all points on the other segment and take the one with the smallest distance
    QgsPoint minDistPoint1;
    double d1 = p11.sqrDistToSegment( p21.x(), p21.y(), p22.x(), p22.y(), minDistPoint1 );
    QgsPoint minDistPoint2;
    double d2 = p12.sqrDistToSegment( p21.x(), p21.y(), p22.x(), p22.y(), minDistPoint2 );
    QgsPoint minDistPoint3;
    double d3 = p21.sqrDistToSegment( p11.x(), p11.y(), p12.x(), p12.y(), minDistPoint3 );
    QgsPoint minDistPoint4;
    double d4 = p22.sqrDistToSegment( p11.x(), p11.y(), p12.x(), p12.y(), minDistPoint4 );

    if ( d1 <= d2 && d1 <= d3 && d1 <= d4 )
    {
      dist = sqrt( d1 ); pt1 = p11; pt2 = minDistPoint1;
      return true;
    }
    else if ( d2 <= d1 && d2 <= d3 && d2 <= d4 )
    {
      dist = sqrt( d2 );  pt1 = p12; pt2 = minDistPoint2;
      return true;
    }
    else if ( d3 <= d1 && d3 <= d2 && d3 <= d4 )
    {
      dist = sqrt( d3 ); pt1 = p21; pt2 = minDistPoint3;
      return true;
    }
    else
    {
      dist = sqrt( d4 ); pt1 = p21; pt2 = minDistPoint4;
      return true;
    }
  }

  double u = ( p1x * v1y - p1y * v1x - p2x * v1y + p2y * v1x ) / denominatorU;
  double t = ( p2x * v2y - p2y * v2x - p1x * v2y + p1y * v2x ) / denominatorT;

  if ( u >= 0 && u <= 1.0 && t >= 0 && t <= 1.0 )
  {
    dist = 0;
    pt1.setX( p2x + u * v2x );
    pt1.setY( p2y + u * v2y );
    pt2 = pt1;
    dist = 0;
    return true;
  }

  if ( t > 1.0 )
  {
    pt1.setX( p12.x() );
    pt1.setY( p12.y() );
  }
  else if ( t < 0.0 )
  {
    pt1.setX( p11.x() );
    pt1.setY( p11.y() );
  }
  if ( u > 1.0 )
  {
    pt2.setX( p22.x() );
    pt2.setY( p22.y() );
  }
  if ( u < 0.0 )
  {
    pt2.setX( p21.x() );
    pt2.setY( p21.y() );
  }
  if ( t >= 0.0 && t <= 1.0 )
  {
    //project pt2 onto g1
    pt2.sqrDistToSegment( p11.x(), p11.y(), p12.x(), p12.y(), pt1 );
  }
  if ( u >= 0.0 && u <= 1.0 )
  {
    //project pt1 onto g2
    pt1.sqrDistToSegment( p21.x(), p21.y(), p22.x(), p22.y(), pt2 );
  }

  dist = sqrt( pt1.sqrDist( pt2 ) );
  return true;
}
Пример #11
0
QgsPoint::QgsPoint( const QgsPoint& p )
{
  m_x = p.x();
  m_y = p.y();
}
Пример #12
0
int QgsTransectSample::createSample( QProgressDialog* pd )
{
  Q_UNUSED( pd );

  if ( !mStrataLayer || !mStrataLayer->isValid() )
  {
    return 1;
  }

  if ( !mBaselineLayer || !mBaselineLayer->isValid() )
  {
    return 2;
  }

  //stratum id is not necessarily an integer
  QVariant::Type stratumIdType = QVariant::Int;
  if ( !mStrataIdAttribute.isEmpty() )
  {
    stratumIdType = mStrataLayer->pendingFields().field( mStrataIdAttribute ).type();
  }

  //create vector file writers for output
  QgsFields outputPointFields;
  outputPointFields.append( QgsField( "id", stratumIdType ) );
  outputPointFields.append( QgsField( "station_id", QVariant::Int ) );
  outputPointFields.append( QgsField( "stratum_id", stratumIdType ) );
  outputPointFields.append( QgsField( "station_code", QVariant::String ) );
  outputPointFields.append( QgsField( "start_lat", QVariant::Double ) );
  outputPointFields.append( QgsField( "start_long", QVariant::Double ) );

  QgsVectorFileWriter outputPointWriter( mOutputPointLayer, "utf-8", outputPointFields, QGis::WKBPoint,
                                         &( mStrataLayer->crs() ) );
  if ( outputPointWriter.hasError() != QgsVectorFileWriter::NoError )
  {
    return 3;
  }

  outputPointFields.append( QgsField( "bearing", QVariant::Double ) ); //add bearing attribute for lines
  QgsVectorFileWriter outputLineWriter( mOutputLineLayer, "utf-8", outputPointFields, QGis::WKBLineString,
                                        &( mStrataLayer->crs() ) );
  if ( outputLineWriter.hasError() != QgsVectorFileWriter::NoError )
  {
    return 4;
  }

  QgsFields usedBaselineFields;
  usedBaselineFields.append( QgsField( "stratum_id", stratumIdType ) );
  usedBaselineFields.append( QgsField( "ok", QVariant::String ) );
  QgsVectorFileWriter usedBaselineWriter( mUsedBaselineLayer, "utf-8", usedBaselineFields, QGis::WKBLineString,
                                          &( mStrataLayer->crs() ) );
  if ( usedBaselineWriter.hasError() != QgsVectorFileWriter::NoError )
  {
    return 5;
  }

  //debug: write clipped buffer bounds with stratum id to same directory as out_point
  QFileInfo outputPointInfo( mOutputPointLayer );
  QString bufferClipLineOutput = outputPointInfo.absolutePath() + "/out_buffer_clip_line.shp";
  QgsFields bufferClipLineFields;
  bufferClipLineFields.append( QgsField( "id", stratumIdType ) );
  QgsVectorFileWriter bufferClipLineWriter( bufferClipLineOutput, "utf-8", bufferClipLineFields, QGis::WKBLineString, &( mStrataLayer->crs() ) );

  //configure distanceArea depending on minDistance units and output CRS
  QgsDistanceArea distanceArea;
  distanceArea.setSourceCrs( mStrataLayer->crs().srsid() );
  if ( mMinDistanceUnits == Meters )
  {
    distanceArea.setEllipsoidalMode( true );
  }
  else
  {
    distanceArea.setEllipsoidalMode( false );
  }

  //possibility to transform output points to lat/long
  QgsCoordinateTransform toLatLongTransform( mStrataLayer->crs(), QgsCoordinateReferenceSystem( 4326, QgsCoordinateReferenceSystem::EpsgCrsId ) );

  //init random number generator
  mt_srand( QTime::currentTime().msec() );

  QgsFeatureRequest fr;
  fr.setSubsetOfAttributes( QStringList() << mStrataIdAttribute << mMinDistanceAttribute << mNPointsAttribute, mStrataLayer->pendingFields() );
  QgsFeatureIterator strataIt = mStrataLayer->getFeatures( fr );

  QgsFeature fet;
  int nTotalTransects = 0;
  int nFeatures = 0;

  if ( pd )
  {
    pd->setMaximum( mStrataLayer->featureCount() );
  }

  while ( strataIt.nextFeature( fet ) )
  {
    if ( pd )
    {
      pd->setValue( nFeatures );
    }
    if ( pd && pd->wasCanceled() )
    {
      break;
    }


    QgsGeometry* strataGeom = fet.geometry();
    if ( !strataGeom )
    {
      continue;
    }

    //find baseline for strata
    bool strataIdOk = true;
    QVariant strataId = fet.attribute( mStrataIdAttribute );
    QgsGeometry* baselineGeom = findBaselineGeometry( strataIdOk ? strataId : -1 );
    if ( !baselineGeom )
    {
      continue;
    }

    double minDistance = fet.attribute( mMinDistanceAttribute ).toDouble();
    double minDistanceLayerUnits = minDistance;
    //if minDistance is in meters and the data in degrees, we need to apply a rough conversion for the buffer distance
    double bufferDist = minDistance;
    if ( mMinDistanceUnits == Meters && mStrataLayer->crs().mapUnits() == QGis::DecimalDegrees )
    {
      bufferDist = minDistance / 111319.9;
      minDistanceLayerUnits = bufferDist;
    }

    QgsGeometry* clippedBaseline = strataGeom->intersection( baselineGeom );
    if ( !clippedBaseline || clippedBaseline->wkbType() == QGis::WKBUnknown )
    {
      delete clippedBaseline;
      continue;
    }
    QgsGeometry* bufferLineClipped = clipBufferLine( strataGeom, clippedBaseline, bufferDist );
    if ( !bufferLineClipped )
    {
      delete clippedBaseline;
      continue;
    }

    //save clipped baseline to file
    QgsFeature blFeature;
    blFeature.setGeometry( *clippedBaseline );
    blFeature.setAttribute( "stratum_id", strataId );
    blFeature.setAttribute( "ok", "f" );
    usedBaselineWriter.addFeature( blFeature );

    //start loop to create random points along the baseline
    int nTransects = fet.attribute( mNPointsAttribute ).toInt();
    int nCreatedTransects = 0;
    int nIterations = 0;
    int nMaxIterations = nTransects * 50;

    QgsSpatialIndex sIndex; //to check minimum distance
    QMap< QgsFeatureId, QgsGeometry* > lineFeatureMap;

    while ( nCreatedTransects < nTransects && nIterations < nMaxIterations )
    {
      double randomPosition = (( double )mt_rand() / MD_RAND_MAX ) * clippedBaseline->length();
      QgsGeometry* samplePoint = clippedBaseline->interpolate( randomPosition );
      ++nIterations;
      if ( !samplePoint )
      {
        continue;
      }
      QgsPoint sampleQgsPoint = samplePoint->asPoint();
      QgsPoint latLongSamplePoint = toLatLongTransform.transform( sampleQgsPoint );

      QgsFeature samplePointFeature;
      samplePointFeature.setGeometry( samplePoint );
      samplePointFeature.setAttribute( "id", nTotalTransects + 1 );
      samplePointFeature.setAttribute( "station_id", nCreatedTransects + 1 );
      samplePointFeature.setAttribute( "stratum_id", strataId );
      samplePointFeature.setAttribute( "station_code", strataId.toString() + "_" + QString::number( nCreatedTransects + 1 ) );
      samplePointFeature.setAttribute( "start_lat", latLongSamplePoint.y() );
      samplePointFeature.setAttribute( "start_long", latLongSamplePoint.x() );

      //find closest point on clipped buffer line
      QgsPoint minDistPoint;

      int afterVertex;
      if ( bufferLineClipped->closestSegmentWithContext( sampleQgsPoint, minDistPoint, afterVertex ) < 0 )
      {
        continue;
      }

      //bearing between sample point and min dist point (transect direction)
      double bearing = distanceArea.bearing( sampleQgsPoint, minDistPoint ) / M_PI * 180.0;

      QgsPolyline sampleLinePolyline;
      QgsPoint ptFarAway( sampleQgsPoint.x() + ( minDistPoint.x() - sampleQgsPoint.x() ) * 1000000,
                          sampleQgsPoint.y() + ( minDistPoint.y() - sampleQgsPoint.y() ) * 1000000 );
      QgsPolyline lineFarAway;
      lineFarAway << sampleQgsPoint << ptFarAway;
      QgsGeometry* lineFarAwayGeom = QgsGeometry::fromPolyline( lineFarAway );
      QgsGeometry* lineClipStratum = lineFarAwayGeom->intersection( strataGeom );
      if ( !lineClipStratum )
      {
        delete lineFarAwayGeom; delete lineClipStratum;
        continue;
      }

      //cancel if distance between sample point and line is too large (line does not start at point
      if ( lineClipStratum->distance( *samplePoint ) > 0.000001 )
      {
        delete lineFarAwayGeom; delete lineClipStratum;
        continue;
      }

      //if lineClipStratum is a multiline, take the part line closest to sampleQgsPoint
      if ( lineClipStratum->wkbType() == QGis::WKBMultiLineString
           || lineClipStratum->wkbType() == QGis::WKBMultiLineString25D )
      {
        QgsGeometry* singleLine = closestMultilineElement( sampleQgsPoint, lineClipStratum );
        if ( singleLine )
        {
          delete lineClipStratum;
          lineClipStratum = singleLine;
        }
      }

      //cancel if length of lineClipStratum is too small
      double transectLength = distanceArea.measure( lineClipStratum );
      if ( transectLength < mMinTransectLength )
      {
        delete lineFarAwayGeom; delete lineClipStratum;
        continue;
      }

      //search closest existing profile. Cancel if dist < minDist
      if ( otherTransectWithinDistance( lineClipStratum, minDistanceLayerUnits, minDistance, sIndex, lineFeatureMap, distanceArea ) )
      {
        delete lineFarAwayGeom; delete lineClipStratum;
        continue;
      }

      QgsFeatureId fid( nCreatedTransects );
      QgsFeature sampleLineFeature( fid );
      sampleLineFeature.setGeometry( lineClipStratum );
      sampleLineFeature.setAttribute( "id", nTotalTransects + 1 );
      sampleLineFeature.setAttribute( "station_id", nCreatedTransects + 1 );
      sampleLineFeature.setAttribute( "stratum_id", strataId );
      sampleLineFeature.setAttribute( "station_code", strataId.toString() + "_" + QString::number( nCreatedTransects + 1 ) );
      sampleLineFeature.setAttribute( "start_lat", latLongSamplePoint.y() );
      sampleLineFeature.setAttribute( "start_long", latLongSamplePoint.x() );
      sampleLineFeature.setAttribute( "bearing", bearing );
      outputLineWriter.addFeature( sampleLineFeature );

      //add point to file writer here.
      //It can only be written if the corresponding transect has been as well
      outputPointWriter.addFeature( samplePointFeature );

      sIndex.insertFeature( sampleLineFeature );
      lineFeatureMap.insert( fid, sampleLineFeature.geometryAndOwnership() );

      delete lineFarAwayGeom;
      ++nTotalTransects;
      ++nCreatedTransects;
    }
    delete clippedBaseline;

    QgsFeature bufferClipFeature;
    bufferClipFeature.setGeometry( bufferLineClipped );
    bufferClipFeature.setAttribute( "id" , strataId );
    bufferClipLineWriter.addFeature( bufferClipFeature );
    //delete bufferLineClipped;

    //delete all line geometries in spatial index
    QMap< QgsFeatureId, QgsGeometry* >::iterator featureMapIt = lineFeatureMap.begin();
    for ( ; featureMapIt != lineFeatureMap.end(); ++featureMapIt )
    {
      delete( featureMapIt.value() );
    }
    lineFeatureMap.clear();
    delete baselineGeom;

    ++nFeatures;
  }

  if ( pd )
  {
    pd->setValue( mStrataLayer->featureCount() );
  }

  return 0;
}
Пример #13
0
// Slot called when the menu item is triggered
// If you created more menu items / toolbar buttons in initiGui, you should
// create a separate handler for each action - this single run() method will
// not be enough
void Heatmap::run()
{
  HeatmapGui d( mQGisIface->mainWindow(), QgisGui::ModalDialogFlags, &mSessionSettings );

  if ( d.exec() == QDialog::Accepted )
  {
    // everything runs here

    // Get the required data from the dialog
    QgsRectangle myBBox = d.bbox();
    int columns = d.columns();
    int rows = d.rows();
    double cellsize = d.cellSizeX(); // or d.cellSizeY();  both have the same value
    mDecay = d.decayRatio();
    int kernelShape = d.kernelShape();

    // Start working on the input vector
    QgsVectorLayer* inputLayer = d.inputVectorLayer();

    // Getting the rasterdataset in place
    GDALAllRegister();

    GDALDataset *emptyDataset;
    GDALDriver *myDriver;

    myDriver = GetGDALDriverManager()->GetDriverByName( d.outputFormat().toUtf8() );
    if ( myDriver == NULL )
    {
      QMessageBox::information( 0, tr( "GDAL driver error" ), tr( "Cannot open the driver for the specified format" ) );
      return;
    }

    double geoTransform[6] = { myBBox.xMinimum(), cellsize, 0, myBBox.yMinimum(), 0, cellsize };
    emptyDataset = myDriver->Create( d.outputFilename().toUtf8(), columns, rows, 1, GDT_Float32, NULL );
    emptyDataset->SetGeoTransform( geoTransform );
    // Set the projection on the raster destination to match the input layer
    emptyDataset->SetProjection( inputLayer->crs().toWkt().toLocal8Bit().data() );

    GDALRasterBand *poBand;
    poBand = emptyDataset->GetRasterBand( 1 );
    poBand->SetNoDataValue( NO_DATA );

    float* line = ( float * ) CPLMalloc( sizeof( float ) * columns );
    for ( int i = 0; i < columns ; i++ )
    {
      line[i] = NO_DATA;
    }
    // Write the empty raster
    for ( int i = 0; i < rows ; i++ )
    {
      poBand->RasterIO( GF_Write, 0, i, columns, 1, line, columns, 1, GDT_Float32, 0, 0 );
    }

    CPLFree( line );
    //close the dataset
    GDALClose(( GDALDatasetH ) emptyDataset );

    // open the raster in GA_Update mode
    GDALDataset *heatmapDS;
    heatmapDS = ( GDALDataset * ) GDALOpen( TO8F( d.outputFilename() ), GA_Update );
    if ( !heatmapDS )
    {
      QMessageBox::information( 0, tr( "Raster update error" ), tr( "Could not open the created raster for updating. The heatmap was not generated." ) );
      return;
    }
    poBand = heatmapDS->GetRasterBand( 1 );

    QgsAttributeList myAttrList;
    int rField = 0;
    int wField = 0;

    // Handle different radius options
    double radius;
    double radiusToMapUnits = 1;
    int myBuffer = 0;
    if ( d.variableRadius() )
    {
      rField = d.radiusField();
      myAttrList.append( rField );
      QgsDebugMsg( QString( "Radius Field index received: %1" ).arg( rField ) );

      // If not using map units, then calculate a conversion factor to convert the radii to map units
      if ( d.radiusUnit() == HeatmapGui::Meters )
      {
        radiusToMapUnits = mapUnitsOf( 1, inputLayer->crs() );
      }
    }
    else
    {
      radius = d.radius(); // radius returned by d.radius() is already in map units
      myBuffer = bufferSize( radius, cellsize );
    }

    if ( d.weighted() )
    {
      wField = d.weightField();
      myAttrList.append( wField );
    }

    // This might have attributes or mightnot have attibutes at all
    // based on the variableRadius() and weighted()
    QgsFeatureIterator fit = inputLayer->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( myAttrList ) );
    int totalFeatures = inputLayer->featureCount();
    int counter = 0;

    QProgressDialog p( tr( "Creating heatmap" ), tr( "Abort" ), 0, totalFeatures, mQGisIface->mainWindow() );
    p.setWindowModality( Qt::ApplicationModal );
    p.show();

    QgsFeature myFeature;

    while ( fit.nextFeature( myFeature ) )
    {
      counter++;
      p.setValue( counter );
      QApplication::processEvents();
      if ( p.wasCanceled() )
      {
        QMessageBox::information( 0, tr( "Heatmap generation aborted" ), tr( "QGIS will now load the partially-computed raster." ) );
        break;
      }

      QgsGeometry* myPointGeometry;
      myPointGeometry = myFeature.geometry();
      // convert the geometry to point
      QgsPoint myPoint;
      myPoint = myPointGeometry->asPoint();
      // avoiding any empty points or out of extent points
      if (( myPoint.x() < myBBox.xMinimum() ) || ( myPoint.y() < myBBox.yMinimum() )
          || ( myPoint.x() > myBBox.xMaximum() ) || ( myPoint.y() > myBBox.yMaximum() ) )
      {
        continue;
      }

      // If radius is variable then fetch it and calculate new pixel buffer size
      if ( d.variableRadius() )
      {
        radius = myFeature.attribute( rField ).toDouble() * radiusToMapUnits;
        myBuffer = bufferSize( radius, cellsize );
      }

      int blockSize = 2 * myBuffer + 1; //Block SIDE would be more appropriate
      // calculate the pixel position
      unsigned int xPosition, yPosition;
      xPosition = (( myPoint.x() - myBBox.xMinimum() ) / cellsize ) - myBuffer;
      yPosition = (( myPoint.y() - myBBox.yMinimum() ) / cellsize ) - myBuffer;

      // get the data
      float *dataBuffer = ( float * ) CPLMalloc( sizeof( float ) * blockSize * blockSize );
      poBand->RasterIO( GF_Read, xPosition, yPosition, blockSize, blockSize,
                        dataBuffer, blockSize, blockSize, GDT_Float32, 0, 0 );

      double weight = 1.0;
      if ( d.weighted() )
      {
        weight = myFeature.attribute( wField ).toDouble();
      }

      for ( int xp = 0; xp <= myBuffer; xp++ )
      {
        for ( int yp = 0; yp <= myBuffer; yp++ )
        {
          double distance = sqrt( pow( xp, 2.0 ) + pow( yp, 2.0 ) );

          // is pixel outside search bandwidth of feature?
          if ( distance > myBuffer )
          {
            continue;
          }

          double pixelValue = weight * calculateKernelValue( distance, myBuffer, kernelShape );

          // clearing anamolies along the axes
          if ( xp == 0 && yp == 0 )
          {
            pixelValue /= 4;
          }
          else if ( xp == 0 || yp == 0 )
          {
            pixelValue /= 2;
          }

          int pos[4];
          pos[0] = ( myBuffer + xp ) * blockSize + ( myBuffer + yp );
          pos[1] = ( myBuffer + xp ) * blockSize + ( myBuffer - yp );
          pos[2] = ( myBuffer - xp ) * blockSize + ( myBuffer + yp );
          pos[3] = ( myBuffer - xp ) * blockSize + ( myBuffer - yp );
          for ( int p = 0; p < 4; p++ )
          {
            if ( dataBuffer[ pos[p] ] == NO_DATA )
            {
              dataBuffer[ pos[p] ] = 0;
            }
            dataBuffer[ pos[p] ] += pixelValue;
          }
        }
      }

      poBand->RasterIO( GF_Write, xPosition, yPosition, blockSize, blockSize,
                        dataBuffer, blockSize, blockSize, GDT_Float32, 0, 0 );
      CPLFree( dataBuffer );
    }
    // Finally close the dataset
    GDALClose(( GDALDatasetH ) heatmapDS );

    // Open the file in QGIS window
    mQGisIface->addRasterLayer( d.outputFilename(), QFileInfo( d.outputFilename() ).baseName() );
  }
}
Пример #14
0
bool QgsGeorefTransform::transformRasterToWorld( const QgsPoint &raster, QgsPoint &world )
{
  // flip y coordinate due to different CS orientation
  QgsPoint raster_flipped( raster.x(), -raster.y() );
  return gdal_transform( raster_flipped, world, 0 );
}
Пример #15
0
double QgsDistanceArea::computeDistanceBearing(
  const QgsPoint& p1, const QgsPoint& p2,
  double* course1, double* course2 ) const
{
  if ( qgsDoubleNear( p1.x(), p2.x() ) && qgsDoubleNear( p1.y(), p2.y() ) )
    return 0;

  // ellipsoid
  double a = mSemiMajor;
  double b = mSemiMinor;
  double f = 1 / mInvFlattening;

  double p1_lat = DEG2RAD( p1.y() ), p1_lon = DEG2RAD( p1.x() );
  double p2_lat = DEG2RAD( p2.y() ), p2_lon = DEG2RAD( p2.x() );

  double L = p2_lon - p1_lon;
  double U1 = atan(( 1 - f ) * tan( p1_lat ) );
  double U2 = atan(( 1 - f ) * tan( p2_lat ) );
  double sinU1 = sin( U1 ), cosU1 = cos( U1 );
  double sinU2 = sin( U2 ), cosU2 = cos( U2 );
  double lambda = L;
  double lambdaP = 2 * M_PI;

  double sinLambda = 0;
  double cosLambda = 0;
  double sinSigma = 0;
  double cosSigma = 0;
  double sigma = 0;
  double alpha = 0;
  double cosSqAlpha = 0;
  double cos2SigmaM = 0;
  double C = 0;
  double tu1 = 0;
  double tu2 = 0;

  int iterLimit = 20;
  while ( qAbs( lambda - lambdaP ) > 1e-12 && --iterLimit > 0 )
  {
    sinLambda = sin( lambda );
    cosLambda = cos( lambda );
    tu1 = ( cosU2 * sinLambda );
    tu2 = ( cosU1 * sinU2 - sinU1 * cosU2 * cosLambda );
    sinSigma = sqrt( tu1 * tu1 + tu2 * tu2 );
    cosSigma = sinU1 * sinU2 + cosU1 * cosU2 * cosLambda;
    sigma = atan2( sinSigma, cosSigma );
    alpha = asin( cosU1 * cosU2 * sinLambda / sinSigma );
    cosSqAlpha = cos( alpha ) * cos( alpha );
    cos2SigmaM = cosSigma - 2 * sinU1 * sinU2 / cosSqAlpha;
    C = f / 16 * cosSqAlpha * ( 4 + f * ( 4 - 3 * cosSqAlpha ) );
    lambdaP = lambda;
    lambda = L + ( 1 - C ) * f * sin( alpha ) *
             ( sigma + C * sinSigma * ( cos2SigmaM + C * cosSigma * ( -1 + 2 * cos2SigmaM * cos2SigmaM ) ) );
  }

  if ( iterLimit == 0 )
    return -1;  // formula failed to converge

  double uSq = cosSqAlpha * ( a * a - b * b ) / ( b * b );
  double A = 1 + uSq / 16384 * ( 4096 + uSq * ( -768 + uSq * ( 320 - 175 * uSq ) ) );
  double B = uSq / 1024 * ( 256 + uSq * ( -128 + uSq * ( 74 - 47 * uSq ) ) );
  double deltaSigma = B * sinSigma * ( cos2SigmaM + B / 4 * ( cosSigma * ( -1 + 2 * cos2SigmaM * cos2SigmaM ) -
                                       B / 6 * cos2SigmaM * ( -3 + 4 * sinSigma * sinSigma ) * ( -3 + 4 * cos2SigmaM * cos2SigmaM ) ) );
  double s = b * A * ( sigma - deltaSigma );

  if ( course1 )
  {
    *course1 = atan2( tu1, tu2 );
  }
  if ( course2 )
  {
    // PI is added to return azimuth from P2 to P1
    *course2 = atan2( cosU1 * sinLambda, -sinU1 * cosU2 + cosU1 * sinU2 * cosLambda ) + M_PI;
  }

  return s;
}
Пример #16
0
int QgsPoint::onSegment( const QgsPoint& a, const QgsPoint& b ) const
{
  //algorithm from 'graphics GEMS', A. Paeth: 'A Fast 2D Point-on-line test'
  if (
    qAbs(( b.y() - a.y() ) *( m_x - a.x() ) - ( m_y - a.y() ) *( b.x() - a.x() ) )
    >= qMax( qAbs( b.x() - a.x() ), qAbs( b.y() - a.y() ) )
  )
  {
    return 0;
  }
  if (( b.x() < a.x() && a.x() < m_x ) || ( b.y() < a.y() && a.y() < m_y ) )
  {
    return 1;
  }
  if (( m_x < a.x() && a.x() < b.x() ) || ( m_y < a.y() && a.y() < b.y() ) )
  {
    return 1;
  }
  if (( a.x() < b.x() && b.x() < m_x ) || ( a.y() < b.y() && b.y() < m_y ) )
  {
    return 3;
  }
  if (( m_x < b.x() && b.x() < a.x() ) || ( m_y < b.y() && b.y() < a.y() ) )
  {
    return 3;
  }

  return 2;
}
Пример #17
0
double QgsDistanceArea::computeDistanceFlat( const QgsPoint& p1, const QgsPoint& p2 ) const
{
  return sqrt(( p2.x() - p1.x() ) * ( p2.x() - p1.x() ) + ( p2.y() - p1.y() ) * ( p2.y() - p1.y() ) );
}
Пример #18
0
QgsPointV2 QgsMapTool::toMapCoordinates( QgsMapLayer* layer, const QgsPointV2& point )
{
  QgsPoint result = mCanvas->mapSettings().layerToMapCoordinates( layer, QgsPoint( point.x(), point.y() ) );
  return QgsPointV2( result.x(), result.y() );
}
Пример #19
0
bool QgsMapToolIdentify::identifyVectorLayer( QgsVectorLayer *layer, int x, int y )
{
  if ( !layer )
    return false;

  QMap< QString, QString > attributes, derivedAttributes;

  QgsPoint point = mCanvas->getCoordinateTransform()->toMapCoordinates( x, y );

  derivedAttributes.insert( tr( "(clicked coordinate)" ), point.toString() );

  // load identify radius from settings
  QSettings settings;
  double identifyValue = settings.value( "/Map/identifyRadius", QGis::DEFAULT_IDENTIFY_RADIUS ).toDouble();
  QString ellipsoid = settings.value( "/qgis/measure/ellipsoid", GEO_NONE ).toString();

  if ( identifyValue <= 0.0 )
    identifyValue = QGis::DEFAULT_IDENTIFY_RADIUS;

  int featureCount = 0;

  QgsFeatureList featureList;

  // toLayerCoordinates will throw an exception for an 'invalid' point.
  // For example, if you project a world map onto a globe using EPSG 2163
  // and then click somewhere off the globe, an exception will be thrown.
  try
  {
    // create the search rectangle
    double searchRadius = mCanvas->extent().width() * ( identifyValue / 100.0 );

    QgsRectangle r;
    r.setXMinimum( point.x() - searchRadius );
    r.setXMaximum( point.x() + searchRadius );
    r.setYMinimum( point.y() - searchRadius );
    r.setYMaximum( point.y() + searchRadius );

    r = toLayerCoordinates( layer, r );

    layer->select( layer->pendingAllAttributesList(), r, true, true );
    QgsFeature f;
    while ( layer->nextFeature( f ) )
      featureList << QgsFeature( f );
  }
  catch ( QgsCsException & cse )
  {
    Q_UNUSED( cse );
    // catch exception for 'invalid' point and proceed with no features found
    QgsDebugMsg( QString( "Caught CRS exception %1" ).arg( cse.what() ) );
  }

  // init distance/area calculator
  QgsDistanceArea calc;
  if ( !featureList.count() == 0 )
  {
    calc.setEllipsoidalMode( mCanvas->hasCrsTransformEnabled() );
    calc.setEllipsoid( ellipsoid );
    calc.setSourceCrs( layer->crs().srsid() );
  }
  QgsFeatureList::iterator f_it = featureList.begin();

  for ( ; f_it != featureList.end(); ++f_it )
  {
    featureCount++;

    QgsFeatureId fid = f_it->id();
    QMap<QString, QString> derivedAttributes;

    // Calculate derived attributes and insert:
    // measure distance or area depending on geometry type
    if ( layer->geometryType() == QGis::Line )
    {
      double dist = calc.measure( f_it->geometry() );
      QGis::UnitType myDisplayUnits;
      convertMeasurement( calc, dist, myDisplayUnits, false );
      QString str = calc.textUnit( dist, 3, myDisplayUnits, false );  // dist and myDisplayUnits are out params
      derivedAttributes.insert( tr( "Length" ), str );
      if ( f_it->geometry()->wkbType() == QGis::WKBLineString ||
           f_it->geometry()->wkbType() == QGis::WKBLineString25D )
      {
        // Add the start and end points in as derived attributes
        str = QLocale::system().toString( f_it->geometry()->asPolyline().first().x(), 'g', 10 );
        derivedAttributes.insert( tr( "firstX", "attributes get sorted; translation for lastX should be lexically larger than this one" ), str );
        str = QLocale::system().toString( f_it->geometry()->asPolyline().first().y(), 'g', 10 );
        derivedAttributes.insert( tr( "firstY" ), str );
        str = QLocale::system().toString( f_it->geometry()->asPolyline().last().x(), 'g', 10 );
        derivedAttributes.insert( tr( "lastX", "attributes get sorted; translation for firstX should be lexically smaller than this one" ), str );
        str = QLocale::system().toString( f_it->geometry()->asPolyline().last().y(), 'g', 10 );
        derivedAttributes.insert( tr( "lastY" ), str );
      }
    }
    else if ( layer->geometryType() == QGis::Polygon )
    {
      double area = calc.measure( f_it->geometry() );
      QGis::UnitType myDisplayUnits;
      convertMeasurement( calc, area, myDisplayUnits, true );  // area and myDisplayUnits are out params
      QString str = calc.textUnit( area, 3, myDisplayUnits, true );
      derivedAttributes.insert( tr( "Area" ), str );
    }
    else if ( layer->geometryType() == QGis::Point &&
              ( f_it->geometry()->wkbType() == QGis::WKBPoint ||
                f_it->geometry()->wkbType() == QGis::WKBPoint25D ) )
    {
      // Include the x and y coordinates of the point as a derived attribute
      QString str;
      str = QLocale::system().toString( f_it->geometry()->asPoint().x(), 'g', 10 );
      derivedAttributes.insert( "X", str );
      str = QLocale::system().toString( f_it->geometry()->asPoint().y(), 'g', 10 );
      derivedAttributes.insert( "Y", str );
    }

    derivedAttributes.insert( tr( "feature id" ), fid < 0 ? tr( "new feature" ) : FID_TO_STRING( fid ) );

    results()->addFeature( layer, *f_it, derivedAttributes );
  }

  QgsDebugMsg( "Feature count on identify: " + QString::number( featureCount ) );

  return featureCount > 0;
}
Пример #20
0
QPoint QgsMapTool::toCanvasCoordinates( const QgsPoint& point )
{
  qreal x = point.x(), y = point.y();
  mCanvas->getCoordinateTransform()->transformInPlace( x, y );
  return QPoint( qRound( x ), qRound( y ) );
}
Пример #21
0
void writePoint( struct Map_info* map, int type, const QgsPoint& point, struct line_cats *cats )
{
  Vect_reset_line( line );
  Vect_append_point( line, point.x(), point.y(), 0 );
  Vect_write_line( map, type, line, cats );
}
Пример #22
0
double QgsLineString::closestSegment( const QgsPoint &pt, QgsPoint &segmentPt,  QgsVertexId &vertexAfter, int *leftOf, double epsilon ) const
{
  double sqrDist = std::numeric_limits<double>::max();
  double leftOfDist = std::numeric_limits<double>::max();
  int prevLeftOf = 0;
  double prevLeftOfX = 0.0;
  double prevLeftOfY = 0.0;
  double testDist = 0;
  double segmentPtX, segmentPtY;

  if ( leftOf )
    *leftOf = 0;

  int size = mX.size();
  if ( size == 0 || size == 1 )
  {
    vertexAfter = QgsVertexId( 0, 0, 0 );
    return -1;
  }
  for ( int i = 1; i < size; ++i )
  {
    double prevX = mX.at( i - 1 );
    double prevY = mY.at( i - 1 );
    double currentX = mX.at( i );
    double currentY = mY.at( i );
    testDist = QgsGeometryUtils::sqrDistToLine( pt.x(), pt.y(), prevX, prevY, currentX, currentY, segmentPtX, segmentPtY, epsilon );
    if ( testDist < sqrDist )
    {
      sqrDist = testDist;
      segmentPt.setX( segmentPtX );
      segmentPt.setY( segmentPtY );
      vertexAfter.part = 0;
      vertexAfter.ring = 0;
      vertexAfter.vertex = i;
    }
    if ( leftOf && qgsDoubleNear( testDist, sqrDist ) )
    {
      int left = QgsGeometryUtils::leftOfLine( pt.x(), pt.y(), prevX, prevY, currentX, currentY );
      // if left equals 0, the test could not be performed (e.g. point in line with segment or on segment)
      // so don't set leftOf in this case, and hope that there's another segment that's the same distance
      // where we can perform the check
      if ( left != 0 )
      {
        if ( qgsDoubleNear( testDist, leftOfDist ) && left != prevLeftOf && prevLeftOf != 0 )
        {
          // we have two possible segments each with equal distance to point, but they disagree
          // on whether or not the point is to the left of them.
          // so we test the segments themselves and flip the result.
          // see https://stackoverflow.com/questions/10583212/elegant-left-of-test-for-polyline
          *leftOf = -QgsGeometryUtils::leftOfLine( currentX, currentY, prevLeftOfX, prevLeftOfY, prevX, prevY );
        }
        else
        {
          *leftOf = left;
        }
        prevLeftOf = *leftOf;
        leftOfDist = testDist;
        prevLeftOfX = prevX;
        prevLeftOfY = prevY;
      }
      else if ( testDist < leftOfDist )
      {
        *leftOf = left;
        leftOfDist = testDist;
        prevLeftOf = 0;
      }
    }
  }
  return sqrDist;
}
Пример #23
0
void QgsGCPCanvasItem::paint( QPainter* p )
{
  QgsRenderContext context;
  if ( !setRenderContextVariables( p, context ) )
  {
    return;
  }

  p->setRenderHint( QPainter::Antialiasing );

  bool enabled = true;
  QgsPoint worldCoords;
  int id = -1;

  if ( mDataPoint )
  {
    enabled = mDataPoint->isEnabled();
    worldCoords = mDataPoint->mapCoords();
    id = mDataPoint->id();
  }

  p->setOpacity( enabled ? 1.0 : 0.3 );

  // draw the point
  p->setPen( Qt::black );
  p->setBrush( mPointBrush );
  p->drawEllipse( -2, -2, 5, 5 );

  QSettings s;
  bool showIDs = s.value( "/Plugin-GeoReferencer/Config/ShowId" ).toBool();
  bool showCoords = s.value( "/Plugin-GeoReferencer/Config/ShowCoords" ).toBool();

  QString msg;
  if ( showIDs && showCoords )
  {
    msg = QString( "%1\nX %2\nY %3" ).arg( QString::number( id ), QString::number( worldCoords.x(), 'f' ), QString::number( worldCoords.y(), 'f' ) );
  }
  else if ( showIDs )
  {
    msg = msg = QString::number( id );
  }
  else if ( showCoords )
  {
    msg = QString( "X %1\nY %2" ).arg( QString::number( worldCoords.x(), 'f' ), QString::number( worldCoords.y(), 'f' ) );
  }

  if ( !msg.isEmpty() )
  {
    p->setBrush( mLabelBrush );
    QFont textFont( "helvetica" );
    textFont.setPixelSize( fontSizePainterUnits( 12, context ) );
    p->setFont( textFont );
    QRectF textBounds = p->boundingRect( 3 * context.scaleFactor(), 3 * context.scaleFactor(), 5 * context.scaleFactor(), 5 * context.scaleFactor(), Qt::AlignLeft, msg );
    mTextBoxRect = QRectF( textBounds.x() - context.scaleFactor() * 1, textBounds.y() - context.scaleFactor() * 1,
                           textBounds.width() + 2 * context.scaleFactor(), textBounds.height() + 2 * context.scaleFactor() );
    p->drawRect( mTextBoxRect );
    p->drawText( textBounds, Qt::AlignLeft, msg );
  }

  if ( data( 1 ) != "composer" ) //draw residuals only on screen
  {
    drawResidualArrow( p, context );
  }
}
Пример #24
0
void QgsGeometryAnalyzer::createOffsetGeometry( QgsGeometry* geom, QgsGeometry* lineGeom, double offset )
{
  if ( !geom || !lineGeom )
  {
    return;
  }

  QList<QgsGeometry*> inputGeomList;

  if ( geom->isMultipart() )
  {
    inputGeomList = geom->asGeometryCollection();
  }
  else
  {
    inputGeomList.push_back( geom );
  }

  QList<GEOSGeometry*> outputGeomList;
  QList<QgsGeometry*>::const_iterator inputGeomIt = inputGeomList.constBegin();
  for ( ; inputGeomIt != inputGeomList.constEnd(); ++inputGeomIt )
  {
    if ( geom->type() == QGis::Line )
    {
      //geos 3.3 needed for line offsets
#if defined(GEOS_VERSION_MAJOR) && defined(GEOS_VERSION_MINOR) && \
      ((GEOS_VERSION_MAJOR>3) || ((GEOS_VERSION_MAJOR==3) && (GEOS_VERSION_MINOR>=3)))
      outputGeomList.push_back( GEOSOffsetCurve(( *inputGeomIt )->asGeos(), -offset, 8 /*quadSegments*/, 0 /*joinStyle*/, 5.0 /*mitreLimit*/ ) );
#else
      outputGeomList.push_back( GEOSGeom_clone(( *inputGeomIt )->asGeos() ) );
#endif
    }
    else if ( geom->type() == QGis::Point )
    {
      QgsPoint p = ( *inputGeomIt )->asPoint();
      p = createPointOffset( p.x(), p.y(), offset, lineGeom );
      GEOSCoordSequence* ptSeq = GEOSCoordSeq_create( 1, 2 );
      GEOSCoordSeq_setX( ptSeq, 0, p.x() );
      GEOSCoordSeq_setY( ptSeq, 0, p.y() );
      GEOSGeometry* geosPt = GEOSGeom_createPoint( ptSeq );
      outputGeomList.push_back( geosPt );
    }
  }

  if ( !geom->isMultipart() )
  {
    GEOSGeometry* outputGeom = outputGeomList.at( 0 );
    if ( outputGeom )
    {
      geom->fromGeos( outputGeom );
    }
  }
  else
  {
    GEOSGeometry** geomArray = new GEOSGeometry*[outputGeomList.size()];
    for ( int i = 0; i < outputGeomList.size(); ++i )
    {
      geomArray[i] = outputGeomList.at( i );
    }
    GEOSGeometry* collection = 0;
    if ( geom->type() == QGis::Point )
    {
      collection = GEOSGeom_createCollection( GEOS_MULTIPOINT, geomArray, outputGeomList.size() );
    }
    else if ( geom->type() == QGis::Line )
    {
      collection = GEOSGeom_createCollection( GEOS_MULTILINESTRING, geomArray, outputGeomList.size() );
    }
    geom->fromGeos( collection );
    delete[] geomArray;
  }
}
Пример #25
0
void GlobePlugin::setupMap()
{
  QSettings settings;
  QString cacheDirectory = settings.value( "cache/directory", QgsApplication::qgisSettingsDirPath() + "cache" ).toString();

#if OSGEARTH_VERSION_GREATER_OR_EQUAL( 2, 2, 0 )
  FileSystemCacheOptions cacheOptions;
  cacheOptions.rootPath() = cacheDirectory.toStdString();
#else
  TMSCacheOptions cacheOptions;
  cacheOptions.setPath( cacheDirectory.toStdString() );
#endif

  MapOptions mapOptions;
  mapOptions.cache() = cacheOptions;
  osgEarth::Map *map = new osgEarth::Map( mapOptions );

  //Default image layer
  /*
  GDALOptions driverOptions;
  driverOptions.url() = QDir::cleanPath( QgsApplication::pkgDataPath() + "/globe/world.tif" ).toStdString();
  ImageLayerOptions layerOptions( "world", driverOptions );
  map->addImageLayer( new osgEarth::ImageLayer( layerOptions ) );
  */

  MapNodeOptions nodeOptions;
  //nodeOptions.proxySettings() =
  //nodeOptions.enableLighting() = false;

  //LoadingPolicy loadingPolicy( LoadingPolicy::MODE_SEQUENTIAL );
  TerrainOptions terrainOptions;
  //terrainOptions.loadingPolicy() = loadingPolicy;
  terrainOptions.compositingTechnique() = TerrainOptions::COMPOSITING_MULTITEXTURE_FFP;
  //terrainOptions.lodFallOff() = 6.0;
  nodeOptions.setTerrainOptions( terrainOptions );

  // The MapNode will render the Map object in the scene graph.
  mMapNode = new osgEarth::MapNode( map, nodeOptions );

  if ( settings.value( "/Plugin-Globe/baseLayerEnabled", true ).toBool() )
  {
    setBaseMap( settings.value( "/Plugin-Globe/baseLayerURL", "http://readymap.org/readymap/tiles/1.0.0/7/" ).toString() );
  }

  mRootNode = new osg::Group();
  mRootNode->addChild( mMapNode );

  // Add layers to the map
  imageLayersChanged();
  elevationLayersChanged();

  // model placement utils
#ifdef HAVE_OSGEARTH_ELEVATION_QUERY
#else
  mElevationManager = new osgEarth::Util::ElevationManager( mMapNode->getMap() );
  mElevationManager->setTechnique( osgEarth::Util::ElevationManager::TECHNIQUE_GEOMETRIC );
  mElevationManager->setMaxTilesToCache( 50 );

  mObjectPlacer = new osgEarth::Util::ObjectPlacer( mMapNode );

  // place 3D model on point layer
  if ( mSettingsDialog->modelLayer() && !mSettingsDialog->modelPath().isEmpty() )
  {
    osg::Node* model = osgDB::readNodeFile( mSettingsDialog->modelPath().toStdString() );
    if ( model )
    {
      QgsVectorLayer* layer = mSettingsDialog->modelLayer();
      QgsFeatureIterator fit = layer->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) ); //TODO: select only visible features
      QgsFeature feature;
      while ( fit.nextFeature( feature ) )
      {
        QgsPoint point = feature.geometry()->asPoint();
        placeNode( model, point.y(), point.x() );
      }
    }
  }
#endif

}
Пример #26
0
bool QgsGeometryAnalyzer::clipSegmentByRange( double x1, double y1, double m1, double x2, double y2, double m2, double range1, double range2, QgsPoint& pt1,
    QgsPoint& pt2, bool& secondPointClipped )
{
  bool reversed = m1 > m2;
  double tmp;

  //reverse m1, m2 if necessary (and consequently also x1,x2 / y1, y2)
  if ( reversed )
  {
    tmp = m1;
    m1 = m2;
    m2 = tmp;

    tmp = x1;
    x1 = x2;
    x2 = tmp;

    tmp = y1;
    y1 = y2;
    y2 = tmp;
  }

  //reverse range1, range2 if necessary
  if ( range1 > range2 )
  {
    tmp = range1;
    range1 = range2;
    range2 = tmp;
  }

  //segment completely outside of range
  if ( m2 < range1 || m1 > range2 )
  {
    return false;
  }

  //segment completely inside of range
  if ( m2 <= range2 && m1 >= range1 )
  {
    if ( reversed )
    {
      pt1.setX( x2 ); pt1.setY( y2 );
      pt2.setX( x1 ); pt2.setY( y1 );
    }
    else
    {
      pt1.setX( x1 ); pt1.setY( y1 );
      pt2.setX( x2 ); pt2.setY( y2 );
    }
    secondPointClipped = false;
    return true;
  }

  //m1 inside and m2 not
  if ( m1 >= range1 && m1 <= range2 )
  {
    pt1.setX( x1 ); pt1.setY( y1 );
    double dist = ( range2 - m1 ) / ( m2 - m1 );
    pt2.setX( x1 + ( x2 - x1 ) * dist );
    pt2.setY( y1 + ( y2 - y1 ) * dist );
    secondPointClipped = !reversed;
  }

  //m2 inside and m1 not
  if ( m2 >= range1 && m2 <= range2 )
  {
    pt2.setX( x2 ); pt2.setY( y2 );
    double dist = ( m2 - range1 ) / ( m2 - m1 );
    pt1.setX( x2 - ( x2 - x1 ) * dist );
    pt1.setY( y2 - ( y2 - y1 ) * dist );
    secondPointClipped = reversed;
  }

  //range1 and range 2 both inside the segment
  if ( range1 >= m1 && range2 <= m2 )
  {
    double dist1 = ( range1 - m1 ) / ( m2 - m1 );
    double dist2 = ( range2 - m1 ) / ( m2 - m1 );
    pt1.setX( x1 + ( x2 - x1 ) * dist1 );
    pt1.setY( y1 + ( y2 - y1 ) * dist1 );
    pt2.setX( x1 + ( x2 - x1 ) * dist2 );
    pt2.setY( y1 + ( y2 - y1 ) * dist2 );
    secondPointClipped = true;
  }

  if ( reversed ) //switch p1 and p2
  {
    QgsPoint tmpPt = pt1;
    pt1 = pt2;
    pt2 = tmpPt;
  }

  return true;
}
Пример #27
0
void QgsMapToolSimplify::canvasPressEvent( QMouseEvent * e )
{
  QgsVectorLayer * vlayer = currentVectorLayer();

  if ( !vlayer )
  {
    notifyNotVectorLayer();
    return;
  }

  QgsPoint layerCoords = mCanvas->getCoordinateTransform()->toMapPoint( e->pos().x(), e->pos().y() );

  double r = QgsTolerance::vertexSearchRadius( vlayer, mCanvas->mapSettings() );
  QgsRectangle selectRect = QgsRectangle( layerCoords.x() - r, layerCoords.y() - r,
                                          layerCoords.x() + r, layerCoords.y() + r );
  QgsFeatureIterator fit = vlayer->getFeatures( QgsFeatureRequest().setFilterRect( selectRect ).setSubsetOfAttributes( QgsAttributeList() ) );

  QgsGeometry* geometry = QgsGeometry::fromPoint( layerCoords );
  double minDistance = DBL_MAX;
  double currentDistance;

  mSelectedFeature.setValid( false );

  QgsFeature f;
  while ( fit.nextFeature( f ) )
  {
    currentDistance = geometry->distance( *( f.geometry() ) );
    if ( currentDistance < minDistance )
    {
      minDistance = currentDistance;
      mSelectedFeature = f;
    }
  }

  // delete previous rubberband (if any)
  removeRubberBand();

  if ( mSelectedFeature.isValid() )
  {
    if ( mSelectedFeature.geometry()->isMultipart() )
    {
      emit messageEmitted( tr( "Multipart features are not supported for simplification." ), QgsMessageBar::CRITICAL );
      return;
    }

    mRubberBand = new QgsRubberBand( mCanvas );
    mRubberBand->setToGeometry( mSelectedFeature.geometry(), 0 );
    mRubberBand->setColor( QColor( 255, 0, 0, 65 ) );
    mRubberBand->setWidth( 2 );
    mRubberBand->show();
    //calculate boudaries for slidebar
    if ( calculateSliderBoudaries() )
    {
      // show dialog as a non-modal window
      mSimplifyDialog->show();
    }
    else
    {
      emit messageEmitted( tr( "This feature cannot be simplified. Check if feature has enough vertices to be simplified." ), QgsMessageBar::WARNING );
    }
  }
}
Пример #28
0
void QgsGeometryAnalyzer::locateAlongSegment( double x1, double y1, double m1, double x2, double y2, double m2, double measure, bool& pt1Ok, QgsPoint& pt1, bool& pt2Ok, QgsPoint& pt2 )
{
  bool reversed = false;
  pt1Ok = false;
  pt2Ok = false;
  double tolerance = 0.000001; //work with a small tolerance to catch e.g. locations at endpoints

  if ( m1 > m2 )
  {
    double tmp = m1;
    m1 = m2;
    m2 = tmp;
    reversed = true;
  }

  //segment does not match
  if (( m1 - measure ) > tolerance || ( measure - m2 ) > tolerance )
  {
    pt1Ok = false;
    pt2Ok = false;
    return;
  }

  //match with vertex1
  if ( qgsDoubleNear( m1, measure, tolerance ) )
  {
    if ( reversed )
    {
      pt2Ok = true;
      pt2.setX( x2 ); pt2.setY( y2 );
    }
    else
    {
      pt1Ok = true;
      pt1.setX( x1 ); pt1.setY( y1 );
    }
  }

  //match with vertex2
  if ( qgsDoubleNear( m2, measure, tolerance ) )
  {
    if ( reversed )
    {
      pt1Ok = true;
      pt1.setX( x1 ); pt1.setY( y1 );
    }
    else
    {
      pt2Ok = true;
      pt2.setX( x2 ); pt2.setY( y2 );
    }
  }


  if ( pt1Ok || pt2Ok )
  {
    return;
  }

  //match between the vertices
  if ( qgsDoubleNear( m1, m2 ) )
  {
    pt1.setX( x1 );
    pt1.setY( y1 );
    pt1Ok = true;
    return;
  }
  double dist = ( measure - m1 ) / ( m2 - m1 );
  if ( reversed )
  {
    dist = 1 - dist;
  }

  pt1.setX( x1 + dist * ( x2 - x1 ) );
  pt1.setY( y1 + dist * ( y2 - y1 ) );
  pt1Ok = true;
}
Пример #29
0
bool QgsRectangle::contains( const QgsPoint &p ) const
{
  return xmin <= p.x() && p.x() <= xmax &&
         ymin <= p.y() && p.y() <= ymax;
}
Пример #30
0
QMap< QString, QString > QgsMapToolIdentify::featureDerivedAttributes( QgsFeature *feature, QgsMapLayer *layer )
{
  // Calculate derived attributes and insert:
  // measure distance or area depending on geometry type
  QMap< QString, QString > derivedAttributes;

  // init distance/area calculator
  QString ellipsoid = QgsProject::instance()->readEntry( "Measure", "/Ellipsoid", GEO_NONE );
  QgsDistanceArea calc;
  calc.setEllipsoidalMode( mCanvas->hasCrsTransformEnabled() );
  calc.setEllipsoid( ellipsoid );
  calc.setSourceCrs( layer->crs().srsid() );

  QGis::WkbType wkbType = QGis::WKBNoGeometry;
  QGis::GeometryType geometryType = QGis::NoGeometry;

  if ( feature->geometry() )
  {
    geometryType = feature->geometry()->type();
    wkbType = feature->geometry()->wkbType();
  }

  if ( geometryType == QGis::Line )
  {
    double dist = calc.measure( feature->geometry() );
    QGis::UnitType myDisplayUnits;
    convertMeasurement( calc, dist, myDisplayUnits, false );
    QString str = calc.textUnit( dist, 3, myDisplayUnits, false );  // dist and myDisplayUnits are out params
    derivedAttributes.insert( tr( "Length" ), str );
    if ( wkbType == QGis::WKBLineString || wkbType == QGis::WKBLineString25D )
    {
      // Add the start and end points in as derived attributes
      QgsPoint pnt = mCanvas->mapRenderer()->layerToMapCoordinates( layer, feature->geometry()->asPolyline().first() );
      str = QLocale::system().toString( pnt.x(), 'g', 10 );
      derivedAttributes.insert( tr( "firstX", "attributes get sorted; translation for lastX should be lexically larger than this one" ), str );
      str = QLocale::system().toString( pnt.y(), 'g', 10 );
      derivedAttributes.insert( tr( "firstY" ), str );
      pnt = mCanvas->mapRenderer()->layerToMapCoordinates( layer, feature->geometry()->asPolyline().last() );
      str = QLocale::system().toString( pnt.x(), 'g', 10 );
      derivedAttributes.insert( tr( "lastX", "attributes get sorted; translation for firstX should be lexically smaller than this one" ), str );
      str = QLocale::system().toString( pnt.y(), 'g', 10 );
      derivedAttributes.insert( tr( "lastY" ), str );
    }
  }
  else if ( geometryType == QGis::Polygon )
  {
    double area = calc.measure( feature->geometry() );
    double perimeter = calc.measurePerimeter( feature->geometry() );
    QGis::UnitType myDisplayUnits;
    convertMeasurement( calc, area, myDisplayUnits, true );  // area and myDisplayUnits are out params
    QString str = calc.textUnit( area, 3, myDisplayUnits, true );
    derivedAttributes.insert( tr( "Area" ), str );
    convertMeasurement( calc, perimeter, myDisplayUnits, false );  // perimeter and myDisplayUnits are out params
    str = calc.textUnit( perimeter, 3, myDisplayUnits, false );
    derivedAttributes.insert( tr( "Perimeter" ), str );
  }
  else if ( geometryType == QGis::Point &&
            ( wkbType == QGis::WKBPoint || wkbType == QGis::WKBPoint25D ) )
  {
    // Include the x and y coordinates of the point as a derived attribute
    QgsPoint pnt = mCanvas->mapRenderer()->layerToMapCoordinates( layer, feature->geometry()->asPoint() );
    QString str = QLocale::system().toString( pnt.x(), 'g', 10 );
    derivedAttributes.insert( "X", str );
    str = QLocale::system().toString( pnt.y(), 'g', 10 );
    derivedAttributes.insert( "Y", str );
  }

  return derivedAttributes;
}