mirror of
https://github.com/qgis/QGIS.git
synced 2025-10-31 00:06:02 -04:00
119 lines
4.4 KiB
Python
119 lines
4.4 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
PointsFromPolygons.py
|
|
---------------------
|
|
Date : August 2013
|
|
Copyright : (C) 2013 by Alexander Bruy
|
|
Email : alexander dot bruy 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__ = 'Alexander Bruy'
|
|
__date__ = 'August 2013'
|
|
__copyright__ = '(C) 2013, Alexander Bruy'
|
|
|
|
# This will get replaced with a git SHA1 when you do a git archive
|
|
|
|
__revision__ = '$Format:%H$'
|
|
|
|
from osgeo import gdal
|
|
from qgis.core import QGis, QgsFields, QgsField, QgsFeature, QgsPoint, QgsGeometry
|
|
from PyQt4.QtCore import QVariant
|
|
from processing.core.GeoAlgorithm import GeoAlgorithm
|
|
from processing.core.parameters import ParameterRaster
|
|
from processing.core.parameters import ParameterVector
|
|
from processing.core.outputs import OutputVector
|
|
from processing.tools import dataobjects, vector, raster
|
|
|
|
|
|
class PointsFromPolygons(GeoAlgorithm):
|
|
|
|
INPUT_RASTER = 'INPUT_RASTER'
|
|
RASTER_BAND = 'RASTER_BAND'
|
|
INPUT_VECTOR = 'INPUT_VECTOR'
|
|
OUTPUT_LAYER = 'OUTPUT_LAYER'
|
|
|
|
def defineCharacteristics(self):
|
|
self.name, self.i18n_name = self.trAlgorithm('Generate points (pixel centroids) inside polygons')
|
|
self.group, self.i18n_group = self.trAlgorithm('Vector analysis tools')
|
|
|
|
self.addParameter(ParameterRaster(self.INPUT_RASTER,
|
|
self.tr('Raster layer')))
|
|
self.addParameter(ParameterVector(self.INPUT_VECTOR,
|
|
self.tr('Vector layer'), [ParameterVector.VECTOR_TYPE_POLYGON]))
|
|
self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Points from polygons')))
|
|
|
|
def processAlgorithm(self, progress):
|
|
layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT_VECTOR))
|
|
|
|
rasterPath = unicode(self.getParameterValue(self.INPUT_RASTER))
|
|
|
|
rasterDS = gdal.Open(rasterPath, gdal.GA_ReadOnly)
|
|
geoTransform = rasterDS.GetGeoTransform()
|
|
rasterDS = None
|
|
|
|
fields = QgsFields()
|
|
fields.append(QgsField('id', QVariant.Int, '', 10, 0))
|
|
fields.append(QgsField('poly_id', QVariant.Int, '', 10, 0))
|
|
fields.append(QgsField('point_id', QVariant.Int, '', 10, 0))
|
|
|
|
writer = self.getOutputFromName(self.OUTPUT_LAYER).getVectorWriter(
|
|
fields.toList(), QGis.WKBPoint, layer.crs())
|
|
|
|
outFeature = QgsFeature()
|
|
outFeature.setFields(fields)
|
|
point = QgsPoint()
|
|
|
|
fid = 0
|
|
polyId = 0
|
|
pointId = 0
|
|
|
|
current = 0
|
|
features = vector.features(layer)
|
|
total = 100.0 / len(features)
|
|
for f in features:
|
|
geom = f.geometry()
|
|
bbox = geom.boundingBox()
|
|
|
|
xMin = bbox.xMinimum()
|
|
xMax = bbox.xMaximum()
|
|
yMin = bbox.yMinimum()
|
|
yMax = bbox.yMaximum()
|
|
|
|
(startRow, startColumn) = raster.mapToPixel(xMin, yMax, geoTransform)
|
|
(endRow, endColumn) = raster.mapToPixel(xMax, yMin, geoTransform)
|
|
|
|
for row in xrange(startRow, endRow + 1):
|
|
for col in xrange(startColumn, endColumn + 1):
|
|
(x, y) = raster.pixelToMap(row, col, geoTransform)
|
|
point.setX(x)
|
|
point.setY(y)
|
|
|
|
if geom.contains(point):
|
|
outFeature.setGeometry(QgsGeometry.fromPoint(point))
|
|
outFeature['id'] = fid
|
|
outFeature['poly_id'] = polyId
|
|
outFeature['point_id'] = pointId
|
|
|
|
fid += 1
|
|
pointId += 1
|
|
|
|
writer.addFeature(outFeature)
|
|
|
|
pointId = 0
|
|
polyId += 1
|
|
|
|
current += 1
|
|
progress.setPercentage(int(current * total))
|
|
|
|
del writer
|