# -*- 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. *
* *
***************************************************************************
"""
__authors__ = 'Victor Olaya, Håvard Tveite'
__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 (QgsApplication,
QgsFeatureRequest,
QgsFeatureSink,
QgsFeature,
QgsGeometry,
QgsPointXY,
QgsWkbTypes,
QgsProcessing,
QgsProcessingException,
QgsProcessingParameterFeatureSource,
QgsProcessingParameterFeatureSink,
QgsProcessingParameterNumber)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
from . import voronoi
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class VoronoiPolygons(QgisAlgorithm):
INPUT = 'INPUT'
BUFFER = 'BUFFER'
OUTPUT = 'OUTPUT'
def icon(self):
return QgsApplication.getThemeIcon("/algorithms/mAlgorithmVoronoi.svg")
def svgIconPath(self):
return QgsApplication.iconPath("/algorithms/mAlgorithmVoronoi.svg")
def group(self):
return self.tr('Vector geometry')
def groupId(self):
return 'vectorgeometry'
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.addParameter(
QgsProcessingParameterFeatureSource(
self.INPUT, self.tr('Input layer'),
[QgsProcessing.TypeVectorPoint]))
self.addParameter(
QgsProcessingParameterNumber(
self.BUFFER, self.tr('Buffer region (% of extent)'),
minValue=0.0, maxValue=9999999999, defaultValue=0.0))
self.addParameter(
QgsProcessingParameterFeatureSink(
self.OUTPUT, self.tr('Voronoi polygons'),
type=QgsProcessing.TypeVectorPolygon))
def name(self):
return 'voronoipolygons'
def displayName(self):
return self.tr('Voronoi polygons')
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
if source is None:
raise QgsProcessingException(
self.invalidSourceError(parameters, self.INPUT))
buf = self.parameterAsDouble(parameters, self.BUFFER, context)
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT,
context, source.fields(),
QgsWkbTypes.Polygon,
source.sourceCrs())
if sink is None:
raise QgsProcessingException(
self.invalidSinkError(parameters, self.OUTPUT))
outFeat = QgsFeature()
extent = source.sourceExtent()
extraX = extent.width() * (buf / 100.0)
# Adjust the extent
extent.setXMinimum(extent.xMinimum() - extraX)
extent.setXMaximum(extent.xMaximum() + extraX)
extraY = extent.height() * (buf / 100.0)
extent.setYMinimum(extent.yMinimum() - extraY)
extent.setYMaximum(extent.yMaximum() + extraY)
height = extent.height()
width = extent.width()
c = voronoi.Context()
pts = []
ptDict = {}
ptNdx = -1
# Find the minimum and maximum x and y for the input points
xmin = width
xmax = 0
ymin = height
ymax = 0
features = source.getFeatures()
total = 100.0 / source.featureCount() if source.featureCount() else 0
for current, inFeat in enumerate(features):
if feedback.isCanceled():
break
geom = 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 x < xmin:
xmin = x
if y < ymin:
ymin = y
if x > xmax:
xmax = x
if y > ymax:
ymax = y
feedback.setProgress(int(current * total))
if xmin == xmax or ymin == ymax:
raise QgsProcessingException('The extent of the input points is '
'not a polygon (all the points are '
'on a vertical or horizontal line) '
'- cannot make a Voronoi diagram!')
xyminmax = [xmin, ymin, xmax, ymax]
if len(pts) < 3:
raise QgsProcessingException(
self.tr('Input file should contain at least 3 points. Choose '
'another file and try again.'))
# Eliminate duplicate points
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)
if len(c.polygons) == 0:
raise QgsProcessingException(
self.tr('There were no polygons created.'))
inFeat = QgsFeature()
current = 0
total = 100.0 / len(c.polygons)
# Clip each of the generated "polygons"
for (site, edges) in list(c.polygons.items()):
if feedback.isCanceled():
break
request = QgsFeatureRequest().setFilterFid(ptDict[ids[site]])
inFeat = next(source.getFeatures(request))
boundarypoints = self.clip_voronoi(edges, c, width,
height, extent,
inFeat.geometry().asPoint(),
xyminmax)
ptgeom = QgsGeometry.fromMultiPointXY(boundarypoints)
geom = QgsGeometry(ptgeom.convexHull())
outFeat.setGeometry(geom)
outFeat.setAttributes(inFeat.attributes())
sink.addFeature(outFeat, QgsFeatureSink.FastInsert)
current += 1
feedback.setProgress(int(current * total))
return {self.OUTPUT: dest_id}
def clip_voronoi(self, edges, c, width, height, extent, point, xyminmax):
"""Clip voronoi function based on code written for Inkscape.
Copyright (C) 2010 Alvin Penner, penner@vaxxine.com
Clips one Thiessen polygon (convex polygon) to extent
"""
pt_x = point.x() - extent.xMinimum()
pt_y = point.y() - extent.yMinimum()
(xmin, ymin, xmax, ymax) = xyminmax
def clip_line(x1, y1, x2, y2, w, h):
if x1 < 0 and x2 < 0:
# Completely to the left
return [0, 0, 0, 0]
if x1 > w and x2 > w:
# Completely to the right
return [0, 0, 0, 0]
if y1 < 0 and y2 < 0:
# Completely below
return [0, 0, 0, 0]
if y1 > h and y2 > h:
# Completely above
return [0, 0, 0, 0]
if x1 < 0:
# First point to the left
y1 = (y1 * x2 - y2 * x1) / (x2 - x1)
x1 = 0
if x2 < 0:
# Last point to the left
y2 = (y1 * x2 - y2 * x1) / (x2 - x1)
x2 = 0
if x1 > w:
# First point to the right
y1 = y1 + (w - x1) * (y2 - y1) / (x2 - x1)
x1 = w
if x2 > w:
# Last point to the right
y2 = y1 + (w - x1) * (y2 - y1) / (x2 - x1)
x2 = w
if x1 == x2 and y1 == y2:
return [0, 0, 0, 0]
if y1 < 0:
# First point below
x1 = (x1 * y2 - x2 * y1) / (y2 - y1)
y1 = 0
if y2 < 0:
# Second point below
x2 = (x1 * y2 - x2 * y1) / (y2 - y1)
y2 = 0
if y1 > h:
# First point above
x1 = x1 + (h - y1) * (x2 - x1) / (y2 - y1)
y1 = h
if y2 > h:
# Second point above
x2 = x1 + (h - y1) * (x2 - x1) / (y2 - y1)
y2 = h
return [x1, y1, x2, y2]
bndpoints = []
hasXMin = False
hasYMin = False
hasXMax = False
hasYMax = False
XMinNumber = 0
XMaxNumber = 0
YMinNumber = 0
YMaxNumber = 0
# The same line may appear twice for collinear input points,
# so have to remember which lines have contributed
XMinLine = -1
XMaxLine = -1
YMinLine = -1
YMaxLine = -1
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
)
elif edge[1] >= 0:
# Only one (left) vertex
if c.lines[edge[0]][1] == 0:
# Vertical line
#xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
xtemp = c.vertices[edge[1]][0]
ytemp = 0 - 1
#if c.vertices[edge[1]][1] > height / 2:
# ytemp = height
#else:
# ytemp = 0
else:
# Create an end of the line at the right edge - OK
xtemp = width
ytemp = (c.lines[edge[0]][2] - width *
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
)
elif edge[2] >= 0:
# Only one (right) vertex
if c.lines[edge[0]][1] == 0:
# Vertical line
#xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
xtemp = c.vertices[edge[2]][0]
ytemp = height + 1
#if c.vertices[edge[2]][1] > height / 2:
# ytemp = height
#else:
# ytemp = 0.0
else:
# End the line at the left edge - OK
xtemp = 0.0
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,
)
else:
# No vertex, only a line
if c.lines[edge[0]][1] == 0:
# Vertical line - should not happen
xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
ytemp = 0.0
xend = xtemp
yend = height
else:
# End the line at both edges - ???
xtemp = 0.0
ytemp = c.lines[edge[0]][2] / c.lines[edge[0]][1]
xend = width
yend = (c.lines[edge[0]][2] - width *
c.lines[edge[0]][0]) / c.lines[edge[0]][1]
[x1, y1, x2, y2] = clip_line(
xtemp,
ytemp,
xend,
yend,
width,
height,
)
if x1 or x2 or y1 or y2:
bndpoints.append(QgsPointXY(x1 + extent.xMinimum(),
y1 + extent.yMinimum()))
bndpoints.append(QgsPointXY(x2 + extent.xMinimum(),
y2 + extent.yMinimum()))
if 0 in (x1, x2):
hasXMin = True
if XMinLine != edge[0]:
XMinNumber = XMinNumber + 1
XMinLine = edge[0]
if 0 in (y1, y2):
hasYMin = True
if YMinLine != edge[0]:
YMinNumber = YMinNumber + 1
YMinLine = edge[0]
if height in (y1, y2):
hasYMax = True
if YMaxLine != edge[0]:
YMaxNumber = YMaxNumber + 1
YMaxLine = edge[0]
if width in (x1, x2):
hasXMax = True
if XMaxLine != edge[0]:
XMaxNumber = XMaxNumber + 1
XMaxLine = edge[0]
# Add auxiliary points for corner cases, if necessary (duplicate
# points is not a problem - will be ignored later).
# a) Extreme input points (lowest, leftmost, rightmost, highest)
# A point can be extreme on both axis
if pt_x == xmin: # leftmost point
if XMinNumber == 0:
bndpoints.append(QgsPointXY(extent.xMinimum(),
extent.yMinimum()))
bndpoints.append(QgsPointXY(extent.xMinimum(),
height + extent.yMinimum()))
elif XMinNumber == 1:
if hasYMin:
bndpoints.append(QgsPointXY(extent.xMinimum(),
extent.yMinimum()))
elif hasYMax:
bndpoints.append(QgsPointXY(extent.xMinimum(),
height + extent.yMinimum()))
elif pt_x == xmax: # rightmost point
if XMaxNumber == 0:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
extent.yMinimum()))
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
height + extent.yMinimum()))
elif XMaxNumber == 1:
if hasYMin:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
extent.yMinimum()))
elif HasYMax:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
height + extent.yMinimum()))
if pt_y == ymin: # lowest point
if YMinNumber == 0:
bndpoints.append(QgsPointXY(extent.xMinimum(),
extent.yMinimum()))
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
extent.yMinimum()))
elif YMinNumber == 1:
if hasXMin:
bndpoints.append(QgsPointXY(extent.xMinimum(),
extent.yMinimum()))
elif hasXMax:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
extent.yMinimum()))
elif pt_y == ymax: # highest point
if YMaxNumber == 0:
bndpoints.append(QgsPointXY(extent.xMinimum(),
height + extent.yMinimum()))
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
height + extent.yMinimum()))
elif YMaxNumber == 1:
if hasXMin:
bndpoints.append(QgsPointXY(extent.xMinimum(),
height + extent.yMinimum()))
elif hasXMax:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
height + extent.yMinimum()))
# b) Polygon that covers the x or the y extent:
if hasYMin and hasYMax:
if YMaxNumber > 1:
if hasXMin:
bndpoints.append(QgsPointXY(extent.xMinimum(),
extent.yMinimum()))
elif hasXMax:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
extent.yMinimum()))
elif YMinNumber > 1:
if hasXMin:
bndpoints.append(QgsPointXY(extent.xMinimum(),
height + extent.yMinimum()))
elif hasXMax:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
height + extent.yMinimum()))
elif hasXMin and hasXMax:
if XMaxNumber > 1:
if hasYMin:
bndpoints.append(QgsPointXY(extent.xMinimum(),
extent.yMinimum()))
elif hasYMax:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
extent.yMinimum()))
elif XMinNumber > 1:
if hasYMin:
bndpoints.append(QgsPointXY(extent.xMinimum(),
height + extent.yMinimum()))
elif hasYMax:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
height + extent.yMinimum()))
# c) Simple corners:
if XMinNumber == 1 and YMinNumber == 1 and not hasXMax and not hasYMax:
bndpoints.append(QgsPointXY(extent.xMinimum(),
extent.yMinimum()))
if XMinNumber == 1 and YMaxNumber == 1 and not hasXMax and not hasYMin:
bndpoints.append(QgsPointXY(extent.xMinimum(),
height + extent.yMinimum()))
if XMaxNumber == 1 and YMinNumber == 1 and not hasXMin and not hasYMax:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
extent.yMinimum()))
if XMaxNumber == 1 and YMaxNumber == 1 and not hasXMin and not hasYMin:
bndpoints.append(QgsPointXY(width + extent.xMinimum(),
height + extent.yMinimum()))
return bndpoints