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Optimize extract nodes algorithm

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This commit is contained in:
nirvn 2017-11-13 12:00:03 +07:00
parent 82644fb37f
commit 7cb15c08b9
6 changed files with 196 additions and 124 deletions
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122
python/plugins/processing/algs/qgis/ExtractNodes.py
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@ -1,122 +0,0 @@
# -*- coding: utf-8 -*-
"""
***************************************************************************
ExtractNodes.py
---------------------
Date : August 2012
Copyright : (C) 2012 by Victor Olaya
Email : volayaf at gmail dot com
***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************
"""
__author__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import os
import math
from qgis.PyQt.QtGui import QIcon
from qgis.PyQt.QtCore import QVariant
from qgis.core import (QgsFeature,
QgsGeometry,
QgsWkbTypes,
QgsField,
QgsFeatureSink,
QgsProcessing,
QgsProcessingParameterFeatureSource,
QgsProcessingParameterFeatureSink)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class ExtractNodes(QgisAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
def icon(self):
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'extract_nodes.png'))
def group(self):
return self.tr('Vector geometry')
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
self.tr('Input layer')))
self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Nodes'), QgsProcessing.TypeVectorPoint))
def name(self):
return 'extractnodes'
def displayName(self):
return self.tr('Extract nodes')
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
fields = source.fields()
fields.append(QgsField('node_index', QVariant.Int))
fields.append(QgsField('distance', QVariant.Double))
fields.append(QgsField('angle', QVariant.Double))
out_wkb = QgsWkbTypes.Point
if QgsWkbTypes.hasM(source.wkbType()):
out_wkb = QgsWkbTypes.addM(out_wkb)
if QgsWkbTypes.hasZ(source.wkbType()):
out_wkb = QgsWkbTypes.addZ(out_wkb)
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, out_wkb, source.sourceCrs())
features = source.getFeatures()
total = 100.0 / source.featureCount() if source.featureCount() else 0
for current, f in enumerate(features):
if feedback.isCanceled():
break
input_geometry = f.geometry()
if not input_geometry:
sink.addFeature(f, QgsFeatureSink.FastInsert)
else:
i = 0
for part in input_geometry.constGet().coordinateSequence():
for ring in part:
if feedback.isCanceled():
break
for point in ring:
distance = input_geometry.distanceToVertex(i)
angle = math.degrees(input_geometry.angleAtVertex(i))
attrs = f.attributes()
attrs.append(i)
attrs.append(distance)
attrs.append(angle)
output_feature = QgsFeature()
output_feature.setAttributes(attrs)
output_feature.setGeometry(QgsGeometry(point.clone()))
sink.addFeature(output_feature, QgsFeatureSink.FastInsert)
i += 1
feedback.setProgress(int(current * total))
return {self.OUTPUT: dest_id}

2
python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py
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@ -64,7 +64,6 @@ from .Explode import Explode
from .ExportGeometryInfo import ExportGeometryInfo
from .ExtendLines import ExtendLines
from .ExtentFromLayer import ExtentFromLayer
from .ExtractNodes import ExtractNodes
from .ExtractSpecificNodes import ExtractSpecificNodes
from .FieldPyculator import FieldsPyculator
from .FieldsCalculator import FieldsCalculator
@ -190,7 +189,6 @@ class QGISAlgorithmProvider(QgsProcessingProvider):
ExportGeometryInfo(),
ExtendLines(),
ExtentFromLayer(),
ExtractNodes(),
ExtractSpecificNodes(),
FieldsCalculator(),
FieldsMapper(),

1
src/analysis/CMakeLists.txt
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@ -35,6 +35,7 @@ SET(QGIS_ANALYSIS_SRCS
processing/qgsalgorithmextractbyexpression.cpp
processing/qgsalgorithmextractbyextent.cpp
processing/qgsalgorithmextractbylocation.cpp
processing/qgsalgorithmextractnodes.cpp
processing/qgsalgorithmfiledownloader.cpp
processing/qgsalgorithmfixgeometries.cpp
processing/qgsalgorithmjoinbyattribute.cpp

137
src/analysis/processing/qgsalgorithmextractnodes.cpp Normal file
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@ -0,0 +1,137 @@
/***************************************************************************
qgsalgorithmextractnodes.cpp
--------------------------
begin : November 2017
copyright : (C) 2017 by Mathieu Pellerin
email : nirvn dot asia at gmail dot com
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
#include "qgsalgorithmextractnodes.h"
///@cond PRIVATE
QString QgsExtractNodesAlgorithm::name() const
{
return QStringLiteral( "extractnodes" );
}
QString QgsExtractNodesAlgorithm::displayName() const
{
return QObject::tr( "Extract nodes" );
}
QStringList QgsExtractNodesAlgorithm::tags() const
{
return QObject::tr( "points,vertex,vertices" ).split( ',' );
}
QString QgsExtractNodesAlgorithm::group() const
{
return QObject::tr( "Vector geometry" );
}
QString QgsExtractNodesAlgorithm::shortHelpString() const
{
return QObject::tr( "This algorithm takes a line or polygon layer and generates a point layer with points representing the nodes in the input lines or polygons. The attributes associated to each point are the same ones associated to the line or polygon that the point belongs to." ) +
QStringLiteral( "\n\n" ) +
QObject::tr( "Additional fields are added to the nodes indicating the node index (beginning at 0), distance along original geometry and bisector angle of node for original geometry." );
}
QgsExtractNodesAlgorithm *QgsExtractNodesAlgorithm::createInstance() const
{
return new QgsExtractNodesAlgorithm();
}
void QgsExtractNodesAlgorithm::initAlgorithm( const QVariantMap & )
{
addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INPUT" ), QObject::tr( "Input layer" ) ) );
addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "OUTPUT" ), QObject::tr( "Nodes" ) ) );
}
QVariantMap QgsExtractNodesAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
std::unique_ptr< QgsFeatureSource > featureSource( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
if ( !featureSource )
return QVariantMap();
QgsWkbTypes::Type outputWkbType = QgsWkbTypes::Point;
if ( QgsWkbTypes::hasM( featureSource->wkbType() ) )
{
outputWkbType = QgsWkbTypes::addM( outputWkbType );
}
if ( QgsWkbTypes::hasZ( featureSource->wkbType() ) )
{
outputWkbType = QgsWkbTypes::addZ( outputWkbType );
}
QgsFields outputFields = featureSource->fields();
outputFields.append( QgsField( QStringLiteral( "node_index" ), QVariant::Int, QString(), 10, 0 ) );
outputFields.append( QgsField( QStringLiteral( "distance" ), QVariant::Double, QString(), 20, 6 ) );
outputFields.append( QgsField( QStringLiteral( "angle" ), QVariant::Double, QString(), 20, 6 ) );
QString dest;
std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, outputFields, outputWkbType, featureSource->sourceCrs() ) );
if ( !sink )
return QVariantMap();
double step = featureSource->featureCount() > 0 ? 100.0 / featureSource->featureCount() : 1;
QgsFeatureIterator it = featureSource->getFeatures( QgsFeatureRequest() );
QgsFeature f;
int i = -1;
while ( it.nextFeature( f ) )
{
i++;
if ( feedback->isCanceled() )
{
break;
}
QgsGeometry inputGeom = f.geometry();
if ( inputGeom.isNull() )
{
sink->addFeature( f, QgsFeatureSink::FastInsert );
}
else
{
const QgsCoordinateSequence sequence = inputGeom.constGet()->coordinateSequence();
for ( const QgsRingSequence &part : sequence )
{
int vertexPos = 0;
for ( const QgsPointSequence &ring : part )
{
for ( int j = 0; j < ring.count(); ++ j )
{
double distance = inputGeom.distanceToVertex( vertexPos );
double angle = inputGeom.angleAtVertex( vertexPos ) * 180 / M_PI_2;
QgsAttributes attrs = f.attributes();
attrs << vertexPos
<< distance
<< angle;
QgsFeature outputFeature = QgsFeature();
outputFeature.setAttributes( attrs );
outputFeature.setGeometry( QgsGeometry( ring.at( j ).clone() ) );
sink->addFeature( outputFeature, QgsFeatureSink::FastInsert );
vertexPos++;
}
}
}
}
feedback->setProgress( i * step );
}
QVariantMap outputs;
outputs.insert( QStringLiteral( "OUTPUT" ), dest );
return outputs;
}
///@endcond

56
src/analysis/processing/qgsalgorithmextractnodes.h Normal file
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@ -0,0 +1,56 @@
/***************************************************************************
qgsalgorithmextractnodes.h
-------------------------
begin : November 2017
copyright : (C) 2017 by Mathieu Pellerin
email : nirvn dot asia at gmail dot com
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
#ifndef QGSALGORITHMEXTRACTNODES_H
#define QGSALGORITHMEXTRACTNODES_H
#define SIP_NO_FILE
#include "qgis.h"
#include "qgsprocessingalgorithm.h"
///@cond PRIVATE
/**
* Native extract nodes algorithm.
*/
class QgsExtractNodesAlgorithm : public QgsProcessingAlgorithm
{
public:
QgsExtractNodesAlgorithm() = default;
void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
QString name() const override;
QString displayName() const override;
virtual QStringList tags() const override;
QString group() const override;
QString shortHelpString() const override;
QgsExtractNodesAlgorithm *createInstance() const override SIP_FACTORY;
protected:
virtual QVariantMap processAlgorithm( const QVariantMap &parameters,
QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
};
///@endcond PRIVATE
#endif // QGSALGORITHMEXTRACTNODES_H

2
src/analysis/processing/qgsnativealgorithms.cpp
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@ -32,6 +32,7 @@
#include "qgsalgorithmextractbyexpression.h"
#include "qgsalgorithmextractbyextent.h"
#include "qgsalgorithmextractbylocation.h"
#include "qgsalgorithmextractnodes.h"
#include "qgsalgorithmfiledownloader.h"
#include "qgsalgorithmfixgeometries.h"
#include "qgsalgorithmjoinbyattribute.h"
@ -106,6 +107,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
addAlgorithm( new QgsExtractByExpressionAlgorithm() );
addAlgorithm( new QgsExtractByExtentAlgorithm() );
addAlgorithm( new QgsExtractByLocationAlgorithm() );
addAlgorithm( new QgsExtractNodesAlgorithm() );
addAlgorithm( new QgsFileDownloaderAlgorithm() );
addAlgorithm( new QgsFixGeometriesAlgorithm() );
addAlgorithm( new QgsJoinByAttributeAlgorithm() );