QGIS/python/plugins/processing/algs/qgis/SimplifyGeometries.py
2017-08-22 23:36:42 +10:00

97 lines
3.4 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
SimplifyGeometries.py
---------------------
Date : August 2012
Copyright : (C) 2012 by Victor Olaya
Email : volayaf 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__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import os
from qgis.PyQt.QtGui import QIcon
from qgis.core import (QgsMapToPixelSimplifier,
QgsProcessingParameterEnum,
QgsProcessingParameterNumber)
from processing.algs.qgis.QgisAlgorithm import QgisFeatureBasedAlgorithm
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class SimplifyGeometries(QgisFeatureBasedAlgorithm):
TOLERANCE = 'TOLERANCE'
METHOD = 'METHOD'
def icon(self):
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'simplify.png'))
def group(self):
return self.tr('Vector geometry')
def __init__(self):
super().__init__()
self.tolerance = None
self.method = None
self.simplifier = None
def initParameters(self, config=None):
self.methods = [self.tr('Distance (Douglas-Peucker)'),
'Snap to grid',
'Area (Visvalingam)']
self.addParameter(QgsProcessingParameterEnum(
self.METHOD,
self.tr('Simplification method'),
self.methods, defaultValue=0))
self.addParameter(QgsProcessingParameterNumber(self.TOLERANCE,
self.tr('Tolerance'), minValue=0.0, maxValue=10000000.0, defaultValue=1.0))
def name(self):
return 'simplifygeometries'
def displayName(self):
return self.tr('Simplify geometries')
def outputName(self):
return self.tr('Simplified')
def prepareAlgorithm(self, parameters, context, feedback):
self.tolerance = self.parameterAsDouble(parameters, self.TOLERANCE, context)
self.method = self.parameterAsEnum(parameters, self.METHOD, context)
if self.method != 0:
self.simplifier = QgsMapToPixelSimplifier(QgsMapToPixelSimplifier.SimplifyGeometry, self.tolerance, self.method)
return True
def processFeature(self, feature, feedback):
if feature.hasGeometry():
input_geometry = feature.geometry()
if self.method == 0: # distance
output_geometry = input_geometry.simplify(self.tolerance)
else:
output_geometry = self.simplifier.simplify(input_geometry)
feature.setGeometry(output_geometry)
return feature