mirror of
https://github.com/qgis/QGIS.git
synced 2025-03-06 00:05:02 -05:00
06c4b07222
Since the layer has more complete knowledge of the crs (ie, when provider could not determine crs and user has selected it from the list), and also better knowledge of layer fields (virtual fields, joined fields) we should use these rather than the provider methods.
125 lines
4.9 KiB
Python
125 lines
4.9 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
RandomPointsLayer.py
|
|
---------------------
|
|
Date : April 2014
|
|
Copyright : (C) 2014 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__ = 'April 2014'
|
|
__copyright__ = '(C) 2014, Alexander Bruy'
|
|
|
|
# This will get replaced with a git SHA1 when you do a git archive
|
|
|
|
__revision__ = '$Format:%H$'
|
|
|
|
import os
|
|
import random
|
|
|
|
from qgis.PyQt.QtGui import QIcon
|
|
from qgis.PyQt.QtCore import QVariant
|
|
from qgis.core import (Qgis, QgsGeometry, QgsFields, QgsField, QgsSpatialIndex, QgsWkbTypes,
|
|
QgsPoint, QgsFeature, QgsFeatureRequest)
|
|
|
|
from processing.core.GeoAlgorithm import GeoAlgorithm
|
|
from processing.core.ProcessingLog import ProcessingLog
|
|
from processing.core.parameters import ParameterVector
|
|
from processing.core.parameters import ParameterNumber
|
|
from processing.core.outputs import OutputVector
|
|
from processing.tools import dataobjects, vector
|
|
|
|
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
|
|
|
|
|
|
class RandomPointsLayer(GeoAlgorithm):
|
|
|
|
VECTOR = 'VECTOR'
|
|
POINT_NUMBER = 'POINT_NUMBER'
|
|
MIN_DISTANCE = 'MIN_DISTANCE'
|
|
OUTPUT = 'OUTPUT'
|
|
|
|
def getIcon(self):
|
|
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'random_points.png'))
|
|
|
|
def defineCharacteristics(self):
|
|
self.name, self.i18n_name = self.trAlgorithm('Random points in layer bounds')
|
|
self.group, self.i18n_group = self.trAlgorithm('Vector creation tools')
|
|
self.addParameter(ParameterVector(self.VECTOR,
|
|
self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POLYGON]))
|
|
self.addParameter(ParameterNumber(self.POINT_NUMBER,
|
|
self.tr('Points number'), 1, None, 1))
|
|
self.addParameter(ParameterNumber(self.MIN_DISTANCE,
|
|
self.tr('Minimum distance'), 0.0, None, 0.0))
|
|
|
|
self.addOutput(OutputVector(self.OUTPUT, self.tr('Random points')))
|
|
|
|
def processAlgorithm(self, progress):
|
|
layer = dataobjects.getObjectFromUri(
|
|
self.getParameterValue(self.VECTOR))
|
|
pointCount = int(self.getParameterValue(self.POINT_NUMBER))
|
|
minDistance = float(self.getParameterValue(self.MIN_DISTANCE))
|
|
|
|
bbox = layer.extent()
|
|
idxLayer = vector.spatialindex(layer)
|
|
|
|
fields = QgsFields()
|
|
fields.append(QgsField('id', QVariant.Int, '', 10, 0))
|
|
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
|
|
fields, QgsWkbTypes.Point, layer.crs())
|
|
|
|
nPoints = 0
|
|
nIterations = 0
|
|
maxIterations = pointCount * 200
|
|
total = 100.0 / pointCount
|
|
|
|
index = QgsSpatialIndex()
|
|
points = dict()
|
|
|
|
request = QgsFeatureRequest()
|
|
|
|
random.seed()
|
|
|
|
while nIterations < maxIterations and nPoints < pointCount:
|
|
rx = bbox.xMinimum() + bbox.width() * random.random()
|
|
ry = bbox.yMinimum() + bbox.height() * random.random()
|
|
|
|
pnt = QgsPoint(rx, ry)
|
|
geom = QgsGeometry.fromPoint(pnt)
|
|
ids = idxLayer.intersects(geom.buffer(5, 5).boundingBox())
|
|
if len(ids) > 0 and \
|
|
vector.checkMinDistance(pnt, index, minDistance, points):
|
|
for i in ids:
|
|
f = layer.getFeatures(request.setFilterFid(i)).next()
|
|
tmpGeom = f.geometry()
|
|
if geom.within(tmpGeom):
|
|
f = QgsFeature(nPoints)
|
|
f.initAttributes(1)
|
|
f.setFields(fields)
|
|
f.setAttribute('id', nPoints)
|
|
f.setGeometry(geom)
|
|
writer.addFeature(f)
|
|
index.insertFeature(f)
|
|
points[nPoints] = pnt
|
|
nPoints += 1
|
|
progress.setPercentage(int(nPoints * total))
|
|
nIterations += 1
|
|
|
|
if nPoints < pointCount:
|
|
ProcessingLog.addToLog(ProcessingLog.LOG_INFO,
|
|
self.tr('Can not generate requested number of random points. '
|
|
'Maximum number of attempts exceeded.'))
|
|
|
|
del writer
|