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137 lines
5.2 KiB
Python
137 lines
5.2 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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ExtractSpecificNodes.py
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--------------------
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Date : October 2016
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Copyright : (C) 2016 by Nyall Dawson
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Email : nyall dot dawson at gmail dot com
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************
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"""
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__author__ = 'Nyall Dawson'
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__date__ = 'October 2016'
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__copyright__ = '(C) 2016, Nyall Dawson'
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# This will get replaced with a git SHA1 when you do a git archive323
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__revision__ = '$Format:%H$'
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import math
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from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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from qgis.core import (QgsWkbTypes,
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QgsFeature,
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QgsFeatureSink,
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QgsGeometry,
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QgsField,
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QgsProcessing,
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QgsProcessingParameterFeatureSource,
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QgsProcessingParameterString,
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QgsProcessingParameterFeatureSink,
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QgsProcessingException)
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from qgis.PyQt.QtCore import QVariant
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class ExtractSpecificNodes(QgisAlgorithm):
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INPUT = 'INPUT'
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OUTPUT = 'OUTPUT'
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NODES = 'NODES'
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def group(self):
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return self.tr('Vector geometry')
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def __init__(self):
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super().__init__()
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def initAlgorithm(self, config=None):
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self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
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self.tr('Input layer'), [QgsProcessing.TypeVectorAnyGeometry]))
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self.addParameter(QgsProcessingParameterString(self.NODES,
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self.tr('Node indices'), defaultValue='0'))
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self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Nodes'), QgsProcessing.TypeVectorPoint))
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def name(self):
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return 'extractspecificnodes'
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def displayName(self):
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return self.tr('Extract specific nodes')
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def processAlgorithm(self, parameters, context, feedback):
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source = self.parameterAsSource(parameters, self.INPUT, context)
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fields = source.fields()
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fields.append(QgsField('node_pos', QVariant.Int))
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fields.append(QgsField('node_index', QVariant.Int))
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fields.append(QgsField('distance', QVariant.Double))
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fields.append(QgsField('angle', QVariant.Double))
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fields.append(QgsField('NUM_FIELD', QVariant.Int))
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wkb_type = QgsWkbTypes.Point
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if QgsWkbTypes.hasM(source.wkbType()):
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wkb_type = QgsWkbTypes.addM(wkb_type)
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if QgsWkbTypes.hasZ(source.wkbType()):
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wkb_type = QgsWkbTypes.addZ(wkb_type)
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(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
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fields, wkb_type, source.sourceCrs())
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node_indices_string = self.parameterAsString(parameters, self.NODES, context)
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indices = []
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for node in node_indices_string.split(','):
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try:
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indices.append(int(node))
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except:
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raise QgsProcessingException(
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self.tr('\'{}\' is not a valid node index').format(node))
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features = source.getFeatures()
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total = 100.0 / source.featureCount() if source.featureCount() else 0
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for current, f in enumerate(features):
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if feedback.isCanceled():
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break
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input_geometry = f.geometry()
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if not input_geometry:
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sink.addFeature(f, QgsFeatureSink.FastInsert)
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else:
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total_nodes = input_geometry.constGet().nCoordinates()
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for node in indices:
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if node < 0:
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node_index = total_nodes + node
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else:
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node_index = node
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if node_index < 0 or node_index >= total_nodes:
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continue
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distance = input_geometry.distanceToVertex(node_index)
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angle = math.degrees(input_geometry.angleAtVertex(node_index))
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output_feature = QgsFeature()
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attrs = f.attributes()
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attrs.append(node)
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attrs.append(node_index)
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attrs.append(distance)
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attrs.append(angle)
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output_feature.setAttributes(attrs)
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point = input_geometry.vertexAt(node_index)
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output_feature.setGeometry(QgsGeometry(point))
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sink.addFeature(output_feature, QgsFeatureSink.FastInsert)
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feedback.setProgress(int(current * total))
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return {self.OUTPUT: dest_id}
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