QGIS/python/plugins/processing/algs/qgis/VoronoiPolygons.py
2016-04-29 14:10:26 +02:00

261 lines
9.7 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
VoronoiPolygons.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.core import QGis, QgsFeatureRequest, QgsFeature, QgsGeometry, QgsPoint
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterNumber
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector
from . import voronoi
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class VoronoiPolygons(GeoAlgorithm):
INPUT = 'INPUT'
BUFFER = 'BUFFER'
OUTPUT = 'OUTPUT'
def getIcon(self):
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'voronoi.png'))
def defineCharacteristics(self):
self.name, self.i18n_name = self.trAlgorithm('Voronoi polygons')
self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools')
self.addParameter(ParameterVector(self.INPUT,
self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POINT]))
self.addParameter(ParameterNumber(self.BUFFER,
self.tr('Buffer region'), 0.0, 100.0, 0.0))
self.addOutput(OutputVector(self.OUTPUT, self.tr('Voronoi polygons')))
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT))
buf = self.getParameterValue(self.BUFFER)
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
layer.pendingFields().toList(), QGis.WKBPolygon, layer.crs())
outFeat = QgsFeature()
extent = layer.extent()
extraX = extent.height() * (buf / 100.0)
extraY = extent.width() * (buf / 100.0)
height = extent.height()
width = extent.width()
c = voronoi.Context()
pts = []
ptDict = {}
ptNdx = -1
features = vector.features(layer)
total = 100.0 / len(features)
for current, inFeat in enumerate(features):
geom = QgsGeometry(inFeat.geometry())
point = geom.asPoint()
x = point.x() - extent.xMinimum()
y = point.y() - extent.yMinimum()
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[0], i[1], sitenum=j) for (j,
i) in enumerate(uniqueSet)])
voronoi.voronoi(sl, c)
inFeat = QgsFeature()
current = 0
total = 100.0 / len(c.polygons)
for (site, edges) in c.polygons.iteritems():
request = QgsFeatureRequest().setFilterFid(ptDict[ids[site]])
inFeat = layer.getFeatures(request).next()
lines = self.clip_voronoi(edges, c, width, height, extent, extraX, extraY)
geom = QgsGeometry.fromMultiPoint(lines)
geom = QgsGeometry(geom.convexHull())
outFeat.setGeometry(geom)
outFeat.setAttributes(inFeat.attributes())
writer.addFeature(outFeat)
current += 1
progress.setPercentage(int(current * total))
del writer
def clip_voronoi(self, edges, c, width, height, extent, exX, exY):
"""Clip voronoi function based on code written for Inkscape.
Copyright (C) 2010 Alvin Penner, penner@vaxxine.com
"""
def clip_line(x1, y1, x2, y2, w, h, x, y):
if x1 < 0 - x and x2 < 0 - x:
return [0, 0, 0, 0]
if x1 > w + x and x2 > w + x:
return [0, 0, 0, 0]
if x1 < 0 - x:
y1 = (y1 * x2 - y2 * x1) / (x2 - x1)
x1 = 0 - x
if x2 < 0 - x:
y2 = (y1 * x2 - y2 * x1) / (x2 - x1)
x2 = 0 - x
if x1 > w + x:
y1 = y1 + (w + x - x1) * (y2 - y1) / (x2 - x1)
x1 = w + x
if x2 > w + x:
y2 = y1 + (w + x - x1) * (y2 - y1) / (x2 - x1)
x2 = w + x
if y1 < 0 - y and y2 < 0 - y:
return [0, 0, 0, 0]
if y1 > h + y and y2 > h + y:
return [0, 0, 0, 0]
if x1 == x2 and y1 == y2:
return [0, 0, 0, 0]
if y1 < 0 - y:
x1 = (x1 * y2 - x2 * y1) / (y2 - y1)
y1 = 0 - y
if y2 < 0 - y:
x2 = (x1 * y2 - x2 * y1) / (y2 - y1)
y2 = 0 - y
if y1 > h + y:
x1 = x1 + (h + y - y1) * (x2 - x1) / (y2 - y1)
y1 = h + y
if y2 > h + y:
x2 = x1 + (h + y - y1) * (x2 - x1) / (y2 - y1)
y2 = h + y
return [x1, y1, x2, y2]
lines = []
hasXMin = False
hasYMin = False
hasXMax = False
hasYMax = False
for edge in edges:
if edge[1] >= 0 and edge[2] >= 0:
# Two vertices
[x1, y1, x2, y2] = clip_line(
c.vertices[edge[1]][0],
c.vertices[edge[1]][1],
c.vertices[edge[2]][0],
c.vertices[edge[2]][1],
width,
height,
exX,
exY,
)
elif edge[1] >= 0:
# Only one vertex
if c.lines[edge[0]][1] == 0:
# Vertical line
xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
if c.vertices[edge[1]][1] > (height + exY) / 2:
ytemp = height + exY
else:
ytemp = 0 - exX
else:
xtemp = width + exX
ytemp = (c.lines[edge[0]][2] - (width + exX)
* c.lines[edge[0]][0]) / c.lines[edge[0]][1]
[x1, y1, x2, y2] = clip_line(
c.vertices[edge[1]][0],
c.vertices[edge[1]][1],
xtemp,
ytemp,
width,
height,
exX,
exY,
)
elif edge[2] >= 0:
# Only one vertex
if c.lines[edge[0]][1] == 0:
# Vertical line
xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
if c.vertices[edge[2]][1] > (height + exY) / 2:
ytemp = height + exY
else:
ytemp = 0.0 - exY
else:
xtemp = 0.0 - exX
ytemp = c.lines[edge[0]][2] / c.lines[edge[0]][1]
[x1, y1, x2, y2] = clip_line(
xtemp,
ytemp,
c.vertices[edge[2]][0],
c.vertices[edge[2]][1],
width,
height,
exX,
exY,
)
if x1 or x2 or y1 or y2:
lines.append(QgsPoint(x1 + extent.xMinimum(), y1
+ extent.yMinimum()))
lines.append(QgsPoint(x2 + extent.xMinimum(), y2
+ extent.yMinimum()))
if 0 - exX in (x1, x2):
hasXMin = True
if 0 - exY in (y1, y2):
hasYMin = True
if height + exY in (y1, y2):
hasYMax = True
if width + exX in (x1, x2):
hasXMax = True
if hasXMin:
if hasYMax:
lines.append(QgsPoint(extent.xMinimum() - exX, height
+ extent.yMinimum() + exY))
if hasYMin:
lines.append(QgsPoint(extent.xMinimum() - exX,
extent.yMinimum() - exY))
if hasXMax:
if hasYMax:
lines.append(QgsPoint(width + extent.xMinimum() + exX, height
+ extent.yMinimum() + exY))
if hasYMin:
lines.append(QgsPoint(width + extent.xMinimum() + exX,
extent.yMinimum() - exY))
return lines