mirror of
https://github.com/qgis/QGIS.git
synced 2025-02-28 00:17:30 -05:00
204 lines
7.7 KiB
Python
204 lines
7.7 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__ = '$Format:%H$'
|
|
|
|
from sets import Set
|
|
|
|
from PyQt4.QtCore import *
|
|
|
|
from qgis.core import *
|
|
|
|
from sextante.core.GeoAlgorithm import GeoAlgorithm
|
|
from sextante.core.QGisLayers import QGisLayers
|
|
|
|
from sextante.parameters.ParameterVector import ParameterVector
|
|
|
|
from sextante.outputs.OutputVector import OutputVector
|
|
|
|
from sextante.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 = QGisLayers.getObjectFromUri(self.getParameterValue(self.INPUT))
|
|
|
|
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.pendingFields(),
|
|
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 = QGisLayers.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():
|
|
layer.featureAtId(ptDict[ids[site]], inFeat)
|
|
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
|