mirror of
https://github.com/qgis/QGIS.git
synced 2025-10-31 00:06:02 -04:00
137 lines
5.2 KiB
Python
137 lines
5.2 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
ExtractSpecificNodes.py
|
|
--------------------
|
|
Date : October 2016
|
|
Copyright : (C) 2016 by Nyall Dawson
|
|
Email : nyall dot dawson 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__ = 'Nyall Dawson'
|
|
__date__ = 'October 2016'
|
|
__copyright__ = '(C) 2016, Nyall Dawson'
|
|
|
|
# This will get replaced with a git SHA1 when you do a git archive323
|
|
|
|
__revision__ = '$Format:%H$'
|
|
|
|
import math
|
|
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
|
|
|
|
from qgis.core import (QgsWkbTypes,
|
|
QgsFeature,
|
|
QgsFeatureSink,
|
|
QgsGeometry,
|
|
QgsField,
|
|
QgsProcessing,
|
|
QgsProcessingParameterFeatureSource,
|
|
QgsProcessingParameterString,
|
|
QgsProcessingParameterFeatureSink,
|
|
QgsProcessingException)
|
|
from qgis.PyQt.QtCore import QVariant
|
|
|
|
|
|
class ExtractSpecificNodes(QgisAlgorithm):
|
|
INPUT = 'INPUT'
|
|
OUTPUT = 'OUTPUT'
|
|
NODES = 'NODES'
|
|
|
|
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'), [QgsProcessing.TypeVectorAnyGeometry]))
|
|
self.addParameter(QgsProcessingParameterString(self.NODES,
|
|
self.tr('Node indices'), defaultValue='0'))
|
|
|
|
self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Nodes'), QgsProcessing.TypeVectorPoint))
|
|
|
|
def name(self):
|
|
return 'extractspecificnodes'
|
|
|
|
def displayName(self):
|
|
return self.tr('Extract specific nodes')
|
|
|
|
def processAlgorithm(self, parameters, context, feedback):
|
|
source = self.parameterAsSource(parameters, self.INPUT, context)
|
|
fields = source.fields()
|
|
fields.append(QgsField('node_pos', QVariant.Int))
|
|
fields.append(QgsField('node_index', QVariant.Int))
|
|
fields.append(QgsField('distance', QVariant.Double))
|
|
fields.append(QgsField('angle', QVariant.Double))
|
|
fields.append(QgsField('NUM_FIELD', QVariant.Int))
|
|
|
|
wkb_type = QgsWkbTypes.Point
|
|
if QgsWkbTypes.hasM(source.wkbType()):
|
|
wkb_type = QgsWkbTypes.addM(wkb_type)
|
|
if QgsWkbTypes.hasZ(source.wkbType()):
|
|
wkb_type = QgsWkbTypes.addZ(wkb_type)
|
|
|
|
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
|
|
fields, wkb_type, source.sourceCrs())
|
|
|
|
node_indices_string = self.parameterAsString(parameters, self.NODES, context)
|
|
indices = []
|
|
for node in node_indices_string.split(','):
|
|
try:
|
|
indices.append(int(node))
|
|
except:
|
|
raise QgsProcessingException(
|
|
self.tr('\'{}\' is not a valid node index').format(node))
|
|
|
|
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:
|
|
total_nodes = input_geometry.geometry().nCoordinates()
|
|
|
|
for node in indices:
|
|
if node < 0:
|
|
node_index = total_nodes + node
|
|
else:
|
|
node_index = node
|
|
|
|
if node_index < 0 or node_index >= total_nodes:
|
|
continue
|
|
|
|
distance = input_geometry.distanceToVertex(node_index)
|
|
angle = math.degrees(input_geometry.angleAtVertex(node_index))
|
|
|
|
output_feature = QgsFeature()
|
|
attrs = f.attributes()
|
|
attrs.append(node)
|
|
attrs.append(node_index)
|
|
attrs.append(distance)
|
|
attrs.append(angle)
|
|
output_feature.setAttributes(attrs)
|
|
|
|
point = input_geometry.vertexAt(node_index)
|
|
output_feature.setGeometry(QgsGeometry(point))
|
|
|
|
sink.addFeature(output_feature, QgsFeatureSink.FastInsert)
|
|
|
|
feedback.setProgress(int(current * total))
|
|
|
|
return {self.OUTPUT: dest_id}
|