mirror of
https://github.com/qgis/QGIS.git
synced 2025-03-07 00:02:15 -05:00
1e13d733c2
initAlgorithm() method This allows 2 benefits: - algorithms can be subclassed and have subclasses add additional parameters/outputs to the algorithm. With the previous approach of declaring parameters/outputs in the constructor, it's not possible to call virtual methods to add additional parameters/ outputs (since you can't call virtual methods from a constructor). - initAlgorithm takes a variant map argument, allowing the algorithm to dynamically adjust its declared parameters and outputs according to this configuration map. This potentially allows model algorithms which can be configured to have variable numbers of parameters and outputs at run time. E.g. a "router" algorithm which directs features to one of any number of output sinks depending on some user configured criteria.
139 lines
5.2 KiB
Python
139 lines
5.2 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
RandomPointsExtent.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. *
|
|
* *
|
|
***************************************************************************
|
|
"""
|
|
from builtins import str
|
|
|
|
__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 (QgsGeometry, QgsFeatureSink, QgsRectangle, QgsFeature, QgsFields, QgsWkbTypes,
|
|
QgsField, QgsSpatialIndex, QgsPointXY,
|
|
QgsCoordinateReferenceSystem,
|
|
QgsMessageLog,
|
|
QgsProcessingUtils)
|
|
|
|
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
|
|
from processing.core.parameters import ParameterExtent
|
|
from processing.core.parameters import ParameterNumber
|
|
from processing.core.parameters import ParameterCrs
|
|
from processing.core.outputs import OutputVector
|
|
from processing.tools import vector, dataobjects
|
|
|
|
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
|
|
|
|
|
|
class RandomPointsExtent(QgisAlgorithm):
|
|
|
|
EXTENT = 'EXTENT'
|
|
POINT_NUMBER = 'POINT_NUMBER'
|
|
MIN_DISTANCE = 'MIN_DISTANCE'
|
|
OUTPUT = 'OUTPUT'
|
|
CRS = 'CRS'
|
|
|
|
def icon(self):
|
|
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'random_points.png'))
|
|
|
|
def group(self):
|
|
return self.tr('Vector creation tools')
|
|
|
|
def __init__(self):
|
|
super().__init__()
|
|
|
|
def initAlgorithm(self, config=None):
|
|
self.addParameter(ParameterExtent(self.EXTENT,
|
|
self.tr('Input extent'), optional=False))
|
|
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.addParameter(ParameterCrs(self.CRS,
|
|
self.tr('Output layer CRS'), 'ProjectCrs'))
|
|
self.addOutput(OutputVector(self.OUTPUT, self.tr('Random points'), datatype=[dataobjects.TYPE_VECTOR_POINT]))
|
|
|
|
def name(self):
|
|
return 'randompointsinextent'
|
|
|
|
def displayName(self):
|
|
return self.tr('Random points in extent')
|
|
|
|
def processAlgorithm(self, parameters, context, feedback):
|
|
pointCount = int(self.getParameterValue(self.POINT_NUMBER))
|
|
minDistance = float(self.getParameterValue(self.MIN_DISTANCE))
|
|
extent = str(self.getParameterValue(self.EXTENT)).split(',')
|
|
|
|
crsId = self.getParameterValue(self.CRS)
|
|
crs = QgsCoordinateReferenceSystem()
|
|
crs.createFromUserInput(crsId)
|
|
|
|
xMin = float(extent[0])
|
|
xMax = float(extent[1])
|
|
yMin = float(extent[2])
|
|
yMax = float(extent[3])
|
|
extent = QgsGeometry().fromRect(
|
|
QgsRectangle(xMin, yMin, xMax, yMax))
|
|
|
|
fields = QgsFields()
|
|
fields.append(QgsField('id', QVariant.Int, '', 10, 0))
|
|
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields, QgsWkbTypes.Point, crs, context)
|
|
|
|
nPoints = 0
|
|
nIterations = 0
|
|
maxIterations = pointCount * 200
|
|
total = 100.0 / pointCount if pointCount else 1
|
|
|
|
index = QgsSpatialIndex()
|
|
points = dict()
|
|
|
|
random.seed()
|
|
|
|
while nIterations < maxIterations and nPoints < pointCount:
|
|
rx = xMin + (xMax - xMin) * random.random()
|
|
ry = yMin + (yMax - yMin) * random.random()
|
|
|
|
pnt = QgsPointXY(rx, ry)
|
|
geom = QgsGeometry.fromPoint(pnt)
|
|
if geom.within(extent) and \
|
|
vector.checkMinDistance(pnt, index, minDistance, points):
|
|
f = QgsFeature(nPoints)
|
|
f.initAttributes(1)
|
|
f.setFields(fields)
|
|
f.setAttribute('id', nPoints)
|
|
f.setGeometry(geom)
|
|
writer.addFeature(f, QgsFeatureSink.FastInsert)
|
|
index.insertFeature(f)
|
|
points[nPoints] = pnt
|
|
nPoints += 1
|
|
feedback.setProgress(int(nPoints * total))
|
|
nIterations += 1
|
|
|
|
if nPoints < pointCount:
|
|
QgsMessageLog.logMessage(self.tr('Can not generate requested number of random points. '
|
|
'Maximum number of attempts exceeded.'), self.tr('Processing'), QgsMessageLog.INFO)
|
|
|
|
del writer
|