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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.
138 lines
5.1 KiB
Python
138 lines
5.1 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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PointsFromPolygons.py
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---------------------
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Date : August 2013
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Copyright : (C) 2013 by Alexander Bruy
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Email : alexander dot bruy 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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from builtins import str
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from builtins import range
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__author__ = 'Alexander Bruy'
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__date__ = 'August 2013'
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__copyright__ = '(C) 2013, Alexander Bruy'
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# This will get replaced with a git SHA1 when you do a git archive
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__revision__ = '$Format:%H$'
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from osgeo import gdal
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from qgis.core import (QgsApplication,
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QgsFields,
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QgsField,
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QgsFeature,
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QgsFeatureSink,
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QgsGeometry,
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QgsWkbTypes,
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QgsPointXY,
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QgsProcessingUtils)
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from qgis.PyQt.QtCore import QVariant
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from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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from processing.core.parameters import ParameterRaster
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from processing.core.parameters import ParameterVector
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from processing.core.outputs import OutputVector
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from processing.tools import dataobjects, raster
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class PointsFromPolygons(QgisAlgorithm):
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INPUT_RASTER = 'INPUT_RASTER'
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RASTER_BAND = 'RASTER_BAND'
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INPUT_VECTOR = 'INPUT_VECTOR'
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OUTPUT_LAYER = 'OUTPUT_LAYER'
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def group(self):
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return self.tr('Vector analysis tools')
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def __init__(self):
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super().__init__()
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self.addParameter(ParameterRaster(self.INPUT_RASTER,
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self.tr('Raster layer')))
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self.addParameter(ParameterVector(self.INPUT_VECTOR,
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self.tr('Vector layer'), [dataobjects.TYPE_VECTOR_POLYGON]))
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self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Points from polygons'), datatype=[dataobjects.TYPE_VECTOR_POINT]))
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def name(self):
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return 'generatepointspixelcentroidsinsidepolygons'
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def displayName(self):
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return self.tr('Generate points (pixel centroids) inside polygons')
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def processAlgorithm(self, parameters, context, feedback):
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layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_VECTOR), context)
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rasterPath = str(self.getParameterValue(self.INPUT_RASTER))
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rasterDS = gdal.Open(rasterPath, gdal.GA_ReadOnly)
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geoTransform = rasterDS.GetGeoTransform()
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rasterDS = None
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fields = QgsFields()
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fields.append(QgsField('id', QVariant.Int, '', 10, 0))
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fields.append(QgsField('poly_id', QVariant.Int, '', 10, 0))
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fields.append(QgsField('point_id', QVariant.Int, '', 10, 0))
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writer = self.getOutputFromName(self.OUTPUT_LAYER).getVectorWriter(fields, QgsWkbTypes.Point,
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layer.crs(), context)
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outFeature = QgsFeature()
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outFeature.setFields(fields)
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fid = 0
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polyId = 0
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pointId = 0
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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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geom = f.geometry()
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bbox = geom.boundingBox()
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xMin = bbox.xMinimum()
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xMax = bbox.xMaximum()
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yMin = bbox.yMinimum()
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yMax = bbox.yMaximum()
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(startRow, startColumn) = raster.mapToPixel(xMin, yMax, geoTransform)
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(endRow, endColumn) = raster.mapToPixel(xMax, yMin, geoTransform)
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# use prepared geometries for faster intersection tests
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engine = QgsGeometry.createGeometryEngine(geom.geometry())
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engine.prepareGeometry()
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for row in range(startRow, endRow + 1):
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for col in range(startColumn, endColumn + 1):
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(x, y) = raster.pixelToMap(row, col, geoTransform)
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point = QgsPointXY()
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point.setX(x)
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point.setY(y)
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if engine.contains(point):
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outFeature.setGeometry(QgsGeometry(point))
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outFeature['id'] = fid
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outFeature['poly_id'] = polyId
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outFeature['point_id'] = pointId
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fid += 1
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pointId += 1
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writer.addFeature(outFeature, QgsFeatureSink.FastInsert)
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pointId = 0
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polyId += 1
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feedback.setProgress(int(current * total))
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del writer
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