QGIS/python/plugins/processing/algs/qgis/GeometryConvert.py
2017-10-30 09:14:05 +01:00

235 lines
9.5 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
Gridify.py
---------------------
Date : May 2010
Copyright : (C) 2010 by Michael Minn
Email : pyqgis at michaelminn 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__ = 'Michael Minn'
__date__ = 'May 2010'
__copyright__ = '(C) 2010, Michael Minn'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
from qgis.core import (QgsFeature,
QgsGeometry,
QgsMultiPoint,
QgsMultiLineString,
QgsLineString,
QgsPolygon,
QgsFeatureSink,
QgsWkbTypes,
QgsProcessingException,
QgsProcessingParameterFeatureSource,
QgsProcessingParameterEnum,
QgsProcessingParameterFeatureSink)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
class GeometryConvert(QgisAlgorithm):
INPUT = 'INPUT'
TYPE = 'TYPE'
OUTPUT = 'OUTPUT'
def group(self):
return self.tr('Vector geometry')
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.types = [self.tr('Centroids'),
self.tr('Nodes'),
self.tr('Linestrings'),
self.tr('Multilinestrings'),
self.tr('Polygons')]
self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
self.tr('Input layer')))
self.addParameter(QgsProcessingParameterEnum(self.TYPE,
self.tr('New geometry type'), options=self.types))
self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT,
self.tr('Converted')))
def name(self):
return 'convertgeometrytype'
def displayName(self):
return self.tr('Convert geometry type')
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
index = self.parameterAsEnum(parameters, self.TYPE, context)
if index == 0:
newType = QgsWkbTypes.Point
elif index == 1:
newType = QgsWkbTypes.Point
if QgsWkbTypes.hasM(source.wkbType()):
newType = QgsWkbTypes.addM(newType)
if QgsWkbTypes.hasZ(source.wkbType()):
newType = QgsWkbTypes.addZ(newType)
elif index == 2:
newType = QgsWkbTypes.LineString
if QgsWkbTypes.hasM(source.wkbType()):
newType = QgsWkbTypes.addM(newType)
if QgsWkbTypes.hasZ(source.wkbType()):
newType = QgsWkbTypes.addZ(newType)
elif index == 3:
newType = QgsWkbTypes.MultiLineString
if QgsWkbTypes.hasM(source.wkbType()):
newType = QgsWkbTypes.addM(newType)
if QgsWkbTypes.hasZ(source.wkbType()):
newType = QgsWkbTypes.addZ(newType)
else:
newType = QgsWkbTypes.Polygon
if QgsWkbTypes.hasM(source.wkbType()):
newType = QgsWkbTypes.addM(newType)
if QgsWkbTypes.hasZ(source.wkbType()):
newType = QgsWkbTypes.addZ(newType)
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
source.fields(), newType, source.sourceCrs())
features = source.getFeatures()
total = 100.0 / source.featureCount() if source.featureCount() else 0
for current, f in enumerate(features):
if feedback.isCanceled():
break
if not f.hasGeometry():
sink.addFeature(f, QgsFeatureSink.FastInsert)
else:
for p in self.convertGeometry(f.geometry(), index):
feat = QgsFeature()
feat.setAttributes(f.attributes())
feat.setGeometry(p)
sink.addFeature(feat, QgsFeatureSink.FastInsert)
feedback.setProgress(int(current * total))
return {self.OUTPUT: dest_id}
def convertGeometry(self, geom, target_type):
# returns an array of output geometries for the input geometry
if target_type == 0:
#centroid
return self.convertToCentroid(geom)
elif target_type == 1:
#nodes
return self.convertToNodes(geom)
elif target_type == 2:
#linestrings
return self.convertToLineStrings(geom)
elif target_type == 3:
#multilinestrings
return self.convertToMultiLineStrings(geom)
elif target_type == 4:
#polygon
return self.convertToPolygon(geom)
def convertToCentroid(self, geom):
return [geom.centroid()]
def convertToNodes(self, geom):
mp = QgsMultiPoint()
# TODO: mega inefficient - needs rework when geometry iterators land
# (but at least it doesn't lose Z/M values)
for g in geom.constGet().coordinateSequence():
for r in g:
for p in r:
mp.addGeometry(p)
return [QgsGeometry(mp)]
def convertToLineStrings(self, geom):
if QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.PointGeometry:
raise QgsProcessingException(
self.tr('Cannot convert from {0} to LineStrings').format(QgsWkbTypes.displayString(geom.wkbType())))
elif QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.LineGeometry:
if QgsWkbTypes.isMultiType(geom.wkbType()):
return geom.asGeometryCollection()
else:
#line to line
return [geom]
else:
# polygons to lines
# we just use the boundary here - that consists of all rings in the (multi)polygon
boundary = QgsGeometry(geom.constGet().boundary())
# boundary will be multipart
return boundary.asGeometryCollection()
def convertToMultiLineStrings(self, geom):
if QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.PointGeometry:
raise QgsProcessingException(
self.tr('Cannot convert from {0} to MultiLineStrings').format(QgsWkbTypes.displayString(geom.wkbType())))
elif QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.LineGeometry:
if QgsWkbTypes.isMultiType(geom.wkbType()):
return [geom]
else:
# line to multiLine
ml = QgsMultiLineString()
ml.addGeometry(geom.constGet().clone())
return [QgsGeometry(ml)]
else:
# polygons to multilinestring
# we just use the boundary here - that consists of all rings in the (multi)polygon
return [QgsGeometry(geom.constGet().boundary())]
def convertToPolygon(self, geom):
if QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.PointGeometry and geom.constGet().nCoordinates() < 3:
raise QgsProcessingException(
self.tr('Cannot convert from Point to Polygon').format(QgsWkbTypes.displayString(geom.wkbType())))
elif QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.PointGeometry:
# multipoint with at least 3 points
# TODO: mega inefficient - needs rework when geometry iterators land
# (but at least it doesn't lose Z/M values)
points = []
for g in geom.constGet().coordinateSequence():
for r in g:
for p in r:
points.append(p)
linestring = QgsLineString(points)
linestring.close()
p = QgsPolygon()
p.setExteriorRing(linestring)
return [QgsGeometry(p)]
elif QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.LineGeometry:
if QgsWkbTypes.isMultiType(geom):
parts = []
for i in range(geom.constGet().numGeometries()):
p = QgsPolygon()
linestring = geom.constGet().geometryN(i).clone()
linestring.close()
p.setExteriorRing(linestring)
parts.append(QgsGeometry(p))
return QgsGeometry.collectGeometry(parts)
else:
# linestring to polygon
p = QgsPolygon()
linestring = geom.constGet().clone()
linestring.close()
p.setExteriorRing(linestring)
return [QgsGeometry(p)]
else:
#polygon
if QgsWkbTypes.isMultiType(geom):
return geom.asGeometryCollection()
else:
return [geom]