QGIS/python/plugins/processing/algs/qgis/DensifyGeometriesInterval.py
2015-08-22 14:29:41 +02:00

135 lines
5.2 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
DensifyGeometriesInterval.py by Anita Graser, Dec 2012
based on DensifyGeometries.py
---------------------
Date : October 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__ = 'Anita Graser'
__date__ = 'Dec 2012'
__copyright__ = '(C) 2012, Anita Graser'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
from math import sqrt
from qgis.core import QGis, QgsPoint, QgsGeometry, QgsFeature
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterNumber
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector
class DensifyGeometriesInterval(GeoAlgorithm):
INPUT = 'INPUT'
INTERVAL = 'INTERVAL'
OUTPUT = 'OUTPUT'
def defineCharacteristics(self):
self.name, self.i18n_name = self.trAlgorithm('Densify geometries given an interval')
self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools')
self.addParameter(ParameterVector(self.INPUT,
self.tr('Input layer'),
[ParameterVector.VECTOR_TYPE_POLYGON, ParameterVector.VECTOR_TYPE_LINE]))
self.addParameter(ParameterNumber(self.INTERVAL,
self.tr('Interval between vertices to add'), 0.0, 10000000.0, 1.0))
self.addOutput(OutputVector(self.OUTPUT, self.tr('Densified')))
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT))
interval = self.getParameterValue(self.INTERVAL)
isPolygon = layer.geometryType() == QGis.Polygon
writer = self.getOutputFromName(
self.OUTPUT).getVectorWriter(layer.pendingFields().toList(),
layer.wkbType(), layer.crs())
features = vector.features(layer)
total = 100.0 / float(len(features))
current = 0
for f in features:
featGeometry = QgsGeometry(f.geometry())
attrs = f.attributes()
newGeometry = self.densifyGeometry(featGeometry, interval,
isPolygon)
feature = QgsFeature()
feature.setGeometry(newGeometry)
feature.setAttributes(attrs)
writer.addFeature(feature)
current += 1
progress.setPercentage(int(current * total))
del writer
def densifyGeometry(self, geometry, interval, isPolygon):
output = []
if isPolygon:
if geometry.isMultipart():
polygons = geometry.asMultiPolygon()
for poly in polygons:
p = []
for ring in poly:
p.append(self.densify(ring, interval))
output.append(p)
return QgsGeometry.fromMultiPolygon(output)
else:
rings = geometry.asPolygon()
for ring in rings:
output.append(self.densify(ring, interval))
return QgsGeometry.fromPolygon(output)
else:
if geometry.isMultipart():
lines = geometry.asMultiPolyline()
for points in lines:
output.append(self.densify(points, interval))
return QgsGeometry.fromMultiPolyline(output)
else:
points = geometry.asPolyline()
output = self.densify(points, interval)
return QgsGeometry.fromPolyline(output)
def densify(self, polyline, interval):
output = []
for i in xrange(len(polyline) - 1):
p1 = polyline[i]
p2 = polyline[i + 1]
output.append(p1)
# Calculate necessary number of points between p1 and p2
pointsNumber = sqrt(p1.sqrDist(p2)) / interval
if pointsNumber > 1:
multiplier = 1.0 / float(pointsNumber)
else:
multiplier = 1
for j in xrange(int(pointsNumber)):
delta = multiplier * (j + 1)
x = p1.x() + delta * (p2.x() - p1.x())
y = p1.y() + delta * (p2.y() - p1.y())
output.append(QgsPoint(x, y))
if j + 1 == pointsNumber:
break
output.append(polyline[len(polyline) - 1])
return output