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b1cadb1822
have specific icons, instead of generic qgis icon We consider these 'top level' algorithms, and using the standard algorithm icon should help reflect this and differentiate them from 3rd party algorithms.
128 lines
4.9 KiB
Python
128 lines
4.9 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 processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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from processing.core.parameters import ParameterVector, ParameterString
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from processing.core.outputs import OutputVector
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from processing.tools import dataobjects
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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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QgsApplication,
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QgsProcessingUtils)
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from qgis.PyQt.QtCore import QVariant
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class ExtractSpecificNodes(QgisAlgorithm):
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INPUT_LAYER = 'INPUT_LAYER'
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OUTPUT_LAYER = 'OUTPUT_LAYER'
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NODES = 'NODES'
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def group(self):
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return self.tr('Vector geometry tools')
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def __init__(self):
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super().__init__()
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self.addParameter(ParameterVector(self.INPUT_LAYER,
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self.tr('Input layer'), [dataobjects.TYPE_VECTOR_ANY]))
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self.addParameter(ParameterString(self.NODES,
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self.tr('Node indices'), default='0'))
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self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Nodes'), datatype=[dataobjects.TYPE_VECTOR_POINT]))
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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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layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)
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fields = layer.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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writer = self.getOutputFromName(
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self.OUTPUT_LAYER).getVectorWriter(fields, QgsWkbTypes.Point, layer.crs(), context)
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node_indices_string = self.getParameterValue(self.NODES)
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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 GeoAlgorithmExecutionException(
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self.tr('\'{}\' is not a valid node index').format(node))
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features = QgsProcessingUtils.getFeatures(layer, context)
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total = 100.0 / layer.featureCount() if layer.featureCount() else 0
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for current, f in enumerate(features):
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input_geometry = f.geometry()
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if not input_geometry:
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writer.addFeature(f, QgsFeatureSink.FastInsert)
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else:
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total_nodes = input_geometry.geometry().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.fromPoint(point))
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writer.addFeature(output_feature, QgsFeatureSink.FastInsert)
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feedback.setProgress(int(current * total))
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del writer
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