Nyall Dawson bd7d913379 Refine QgsFeature geometry getters/setters
All pointer based methods have been removed.

Now we have only:

  void setGeometry( const QgsGeometry& geom )

and

  QgsGeometry geometry() const

Benefits include avoiding a whole lot of tricky pointer lifetime
issues, potential memory leaks, and finally closing #777, which
has survived for over 9 years!...

Impacts on PyQGIS code:
- no more need for the messy
  g = QgsGeometry( feature.geometry() )
  workaround, just use g = feature.geometry() instead
- IMPORTANT: you can no longer test whether a feature has geometry
 using `if f.geometry():`, since QgsFeature::geometry() will
 *always* return an object. Instead, use
 `if not f.geometry().isEmpty():`, or preferably the new method
 `if not f.hasGeometry():`

Fix #777
2016-08-01 16:25:46 +10:00

126 lines
4.6 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
Delaunay.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.PyQt.QtCore import QVariant
from qgis.core import Qgis, QgsField, QgsFeatureRequest, QgsFeature, QgsGeometry, QgsPoint
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.tools import dataobjects, vector
from processing.core.parameters import ParameterVector
from processing.core.outputs import OutputVector
from . import voronoi
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class Delaunay(GeoAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
def getIcon(self):
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'delaunay.png'))
def defineCharacteristics(self):
self.name, self.i18n_name = self.trAlgorithm('Delaunay triangulation')
self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools')
self.addParameter(ParameterVector(self.INPUT,
self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POINT]))
self.addOutput(OutputVector(self.OUTPUT,
self.tr('Delaunay triangulation')))
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT))
fields = [QgsField('POINTA', QVariant.Double, '', 24, 15),
QgsField('POINTB', QVariant.Double, '', 24, 15),
QgsField('POINTC', QVariant.Double, '', 24, 15)]
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields,
Qgis.WKBPolygon, layer.crs())
pts = []
ptDict = {}
ptNdx = -1
c = voronoi.Context()
features = vector.features(layer)
total = 100.0 / len(features)
for current, inFeat in enumerate(features):
geom = inFeat.geometry()
point = geom.asPoint()
x = point.x()
y = point.y()
pts.append((x, y))
ptNdx += 1
ptDict[ptNdx] = inFeat.id()
progress.setPercentage(int(current * total))
if len(pts) < 3:
raise GeoAlgorithmExecutionException(
self.tr('Input file should contain at least 3 points. Choose '
'another file and try again.'))
uniqueSet = set(item for item in pts)
ids = [pts.index(item) for item in uniqueSet]
sl = voronoi.SiteList([voronoi.Site(*i) for i in uniqueSet])
c.triangulate = True
voronoi.voronoi(sl, c)
triangles = c.triangles
feat = QgsFeature()
total = 100.0 / len(triangles)
for current, triangle in enumerate(triangles):
indicies = list(triangle)
indicies.append(indicies[0])
polygon = []
attrs = []
step = 0
for index in indicies:
request = QgsFeatureRequest().setFilterFid(ptDict[ids[index]])
inFeat = layer.getFeatures(request).next()
geom = inFeat.geometry()
point = QgsPoint(geom.asPoint())
polygon.append(point)
if step <= 3:
attrs.append(ids[index])
step += 1
feat.setAttributes(attrs)
geometry = QgsGeometry().fromPolygon([polygon])
feat.setGeometry(geometry)
writer.addFeature(feat)
progress.setPercentage(int(current * total))
del writer