# -*- 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__ = '$Format:%H$'
from sets import Set
from PyQt4.QtCore import *
from qgis.core import *
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.tools import dataobjects, vector
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.parameters.ParameterVector import ParameterVector
from processing.outputs.OutputVector import OutputVector
from processing.algs.ftools import voronoi
class VoronoiPolygons(GeoAlgorithm):
INPUT = "INPUT"
OUTPUT = "OUTPUT"
#===========================================================================
# def getIcon(self):
# return QtGui.QIcon(os.path.dirname(__file__) + "/icons/voronoi.png")
#===========================================================================
def defineCharacteristics(self):
self.name = "Voronoi polygons"
self.group = "Vector geometry tools"
self.addParameter(ParameterVector(self.INPUT, "Input layer", [ParameterVector.VECTOR_TYPE_POINT]))
self.addOutput(OutputVector(self.OUTPUT, "Voronoi polygons"))
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT))
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.pendingFields().toList(),
QGis.WKBPolygon, layer.crs())
inFeat = QgsFeature()
outFeat = QgsFeature()
extent = layer.extent()
height = extent.height()
width = extent.width()
c = voronoi.Context()
pts = []
ptDict = {}
ptNdx = -1
features = vector.features(layer)
for inFeat in 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()
if len(pts) < 3:
raise GeoAlgorithmExecutionException("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 / float(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, 0, 0)
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