double QgsGeometryAnalyzer::perimeterMeasure( QgsGeometry* geometry, QgsDistanceArea& measure ) { double value = 0.00; if ( geometry->isMultipart() ) { QgsMultiPolygon poly = geometry->asMultiPolygon(); QgsMultiPolygon::iterator it; QgsPolygon::iterator jt; for ( it = poly.begin(); it != poly.end(); ++it ) { for ( jt = it->begin(); jt != it->end(); ++jt ) { value = value + measure.measure( QgsGeometry::fromPolyline( *jt ) ); } } } else { QgsPolygon::iterator jt; QgsPolygon poly = geometry->asPolygon(); for ( jt = poly.begin(); jt != poly.end(); ++jt ) { value = value + measure.measure( QgsGeometry::fromPolyline( *jt ) ); } } return value; }
void TestQgsDistanceArea::collections() { Q_NOWARN_DEPRECATED_PUSH //test measuring for collections QgsDistanceArea myDa; myDa.setSourceAuthId( "EPSG:4030" ); myDa.setEllipsoidalMode( true ); myDa.setEllipsoid( "WGS84" ); //collection of lines, should be sum of line length QgsGeometry lines( QgsGeometryFactory::geomFromWkt( "GeometryCollection( LineString(0 36.53, 5.76 -48.16), LineString(0 25.54, 24.20 36.70) )" ) ); double result = myDa.measure( &lines ); //should measure length QVERIFY( qgsDoubleNear( result, 12006159, 1 ) ); result = myDa.measureLength( &lines ); QVERIFY( qgsDoubleNear( result, 12006159, 1 ) ); result = myDa.measureArea( &lines ); QVERIFY( qgsDoubleNear( result, 0 ) ); //collection of polygons QgsGeometry polys( QgsGeometryFactory::geomFromWkt( "GeometryCollection( Polygon((0 36.53, 5.76 -48.16, 0 25.54, 0 36.53)), Polygon((10 20, 15 20, 15 10, 10 20)) )" ) ); result = myDa.measure( &polys ); //should measure area QVERIFY( qgsDoubleNear( result, 670434859475LL, 1 ) ); result = myDa.measureArea( &polys ); QVERIFY( qgsDoubleNear( result, 670434859475LL, 1 ) ); result = myDa.measureLength( &polys ); QVERIFY( qgsDoubleNear( result, 0 ) ); //mixed collection QgsGeometry mixed( QgsGeometryFactory::geomFromWkt( "GeometryCollection( LineString(0 36.53, 5.76 -48.16), LineString(0 25.54, 24.20 36.70), Polygon((0 36.53, 5.76 -48.16, 0 25.54, 0 36.53)), Polygon((10 20, 15 20, 15 10, 10 20)) )" ) ); result = myDa.measure( &mixed ); //should measure area QVERIFY( qgsDoubleNear( result, 670434859475LL, 1 ) ); //measure area specifically result = myDa.measureArea( &mixed ); QVERIFY( qgsDoubleNear( result, 670434859475LL, 1 ) ); //measure length result = myDa.measureLength( &mixed ); QVERIFY( qgsDoubleNear( result, 12006159, 1 ) ); Q_NOWARN_DEPRECATED_POP }
QList<double> QgsGeometryAnalyzer::simpleMeasure( QgsGeometry* mpGeometry ) { QList<double> list; double perim; if ( mpGeometry->wkbType() == QGis::WKBPoint ) { QgsPoint pt = mpGeometry->asPoint(); list.append( pt.x() ); list.append( pt.y() ); } else { QgsDistanceArea measure; list.append( measure.measure( mpGeometry ) ); if ( mpGeometry->type() == QGis::Polygon ) { perim = perimeterMeasure( mpGeometry, measure ); list.append( perim ); } } return list; }
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->mapSettings().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->mapSettings().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->mapSettings().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; }
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; } if ( !fet.constGeometry() ) { continue; } const QgsGeometry* strataGeom = fet.constGeometry(); //find baseline for strata QVariant strataId = fet.attribute( mStrataIdAttribute ); QgsGeometry* baselineGeom = findBaselineGeometry( strataId.isValid() ? 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 = bufferDistance( minDistance ); if ( mMinDistanceUnits == Meters && mStrataLayer->crs().mapUnits() == QGis::DecimalDegrees ) { minDistanceLayerUnits = minDistance / 111319.9; } 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 ); Q_NOWARN_DEPRECATED_PUSH lineFeatureMap.insert( fid, sampleLineFeature.geometryAndOwnership() ); Q_NOWARN_DEPRECATED_POP 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; }
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", "WGS84" ).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.setProjectionsEnabled( mCanvas->hasCrsTransformEnabled() ); // project? 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; }
static QVariant fcnGeomLength( const QVariantList& , QgsFeature* f, QgsExpression* parent ) { ENSURE_GEOM_TYPE( f, g, QGis::Line ); QgsDistanceArea* calc = parent->geomCalculator(); return QVariant( calc->measure( f->geometry() ) ); }