95 lines
3.2 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
Buffer.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__ = '$Format:%H$'
from qgis.core import (QgsFeature,
QgsGeometry,
QgsFeatureRequest,
QgsFeatureSink)
def buffering(feedback, context, sink, distance, field, useField, source, dissolve, segments, endCapStyle=1,
joinStyle=1, miterLimit=2):
if useField:
field = source.fields().lookupField(field)
outFeat = QgsFeature()
current = 0
total = 100.0 / source.featureCount() if source.featureCount() else 0
# With dissolve
if dissolve:
attributes_to_fetch = []
if useField:
attributes_to_fetch.append(field)
features = source.getFeatures(QgsFeatureRequest().setSubsetOfAttributes(attributes_to_fetch))
buffered_geometries = []
for inFeat in features:
if feedback.isCanceled():
break
attrs = inFeat.attributes()
if useField:
value = attrs[field]
else:
value = distance
inGeom = inFeat.geometry()
buffered_geometries.append(inGeom.buffer(float(value), segments, endCapStyle, joinStyle, miterLimit))
current += 1
feedback.setProgress(int(current * total))
final_geometry = QgsGeometry.unaryUnion(buffered_geometries)
outFeat.setGeometry(final_geometry)
outFeat.setAttributes(attrs)
sink.addFeature(outFeat, QgsFeatureSink.FastInsert)
else:
features = source.getFeatures()
# Without dissolve
for inFeat in features:
if feedback.isCanceled():
break
attrs = inFeat.attributes()
if useField:
value = attrs[field]
else:
value = distance
inGeom = inFeat.geometry()
outFeat = QgsFeature()
outGeom = inGeom.buffer(float(value), segments, endCapStyle, joinStyle, miterLimit)
outFeat.setGeometry(outGeom)
outFeat.setAttributes(attrs)
sink.addFeature(outFeat, QgsFeatureSink.FastInsert)
current += 1
feedback.setProgress(int(current * total))