2013-03-21 23:17:49 +04:00

131 lines
5.2 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
Clip.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 PyQt4.QtCore import *
from qgis.core import *
from sextante.core.GeoAlgorithm import GeoAlgorithm
from sextante.core.QGisLayers import QGisLayers
from sextante.core.SextanteLog import SextanteLog
from sextante.parameters.ParameterVector import ParameterVector
from sextante.outputs.OutputVector import OutputVector
from sextante.algs.ftools import FToolsUtils as utils
class Clip(GeoAlgorithm):
INPUT = "INPUT"
OVERLAY = "OVERLAY"
OUTPUT = "OUTPUT"
#===========================================================================
# def getIcon(self):
# return QtGui.QIcon(os.path.dirname(__file__) + "/icons/clip.png")
#===========================================================================
def defineCharacteristics(self):
self.name = "Clip"
self.group = "Vector overlay tools"
self.addParameter(ParameterVector(Clip.INPUT, "Input layer", ParameterVector.VECTOR_TYPE_ANY))
self.addParameter(ParameterVector(Clip.OVERLAY, "Clip layer", ParameterVector.VECTOR_TYPE_ANY))
self.addOutput(OutputVector(Clip.OUTPUT, "Clipped"))
def processAlgorithm(self, progress):
layerA = QGisLayers.getObjectFromUri(self.getParameterValue(Clip.INPUT))
layerB = QGisLayers.getObjectFromUri(self.getParameterValue(Clip.OVERLAY))
GEOS_EXCEPT = True
FEATURE_EXCEPT = True
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layerA.pendingFields(),
layerA.dataProvider().geometryType(), layerA.dataProvider().crs())
inFeatA = QgsFeature()
inFeatB = QgsFeature()
outFeat = QgsFeature()
index = utils.createSpatialIndex(layerB)
selectionA = QGisLayers.features(layerA)
current = 0
total = 100.0 / float(len(selectionA))
for inFeatA in selectionA:
geom = QgsGeometry(inFeatA.geometry())
attrs = inFeatA.attributes()
intersections = index.intersects(geom.boundingBox())
first = True
found = False
if len(intersections) > 0:
for i in intersections:
request = QgsFeatureRequest().setFilterFid(i)
inFeatB = layerB.getFeatures(request).next()
tmpGeom = QgsGeometry(inFeatB.geometry())
if tmpGeom.intersects(geom):
found = True
if first:
outFeat.setGeometry(QgsGeometry(tmpGeom))
first = False
else:
try:
cur_geom = QgsGeometry(outFeat.geometry())
new_geom = QgsGeometry(cur_geom.combine(tmpGeom))
outFeat.setGeometry(QgsGeometry(new_geom))
except:
GEOS_EXCEPT = False
break
if found:
try:
cur_geom = QgsGeometry(outFeat.geometry())
new_geom = QgsGeometry(geom.intersection(cur_geom))
if new_geom.wkbType() == QGis.WKBNoGeometry :
int_com = QgsGeometry(geom.combine(cur_geom))
int_sym = QgsGeometry(geom.symDifference(cur_geom))
new_geom = QgsGeometry(int_com.difference(int_sym))
try:
outFeat.setGeometry(new_geom)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat)
except:
FEAT_EXCEPT = False
continue
except:
GEOS_EXCEPT = False
continue
current += 1
progress.setPercentage(int(current * total))
del writer
if not GEOS_EXCEPT:
SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Geometry exception while computing clip")
if not FEATURE_EXCEPT:
SextanteLog.addToLog(SextanteLog.LOG_WARNING, "Feature exception while computing clip")