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252 lines
9.3 KiB
Python
252 lines
9.3 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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VoronoiPolygons.py
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---------------------
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Date : August 2012
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Copyright : (C) 2012 by Victor Olaya
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Email : volayaf at gmail dot com
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************
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"""
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__author__ = 'Victor Olaya'
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__date__ = 'August 2012'
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__copyright__ = '(C) 2012, Victor Olaya'
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# This will get replaced with a git SHA1 when you do a git archive
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__revision__ = '$Format:%H$'
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from sets import Set
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from qgis.core import QGis, QgsFeatureRequest, QgsFeature, QgsGeometry, QgsPoint
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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from processing.core.parameters import ParameterVector
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from processing.core.parameters import ParameterNumber
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from processing.core.outputs import OutputVector
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import voronoi
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from processing.tools import dataobjects, vector
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class VoronoiPolygons(GeoAlgorithm):
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INPUT = 'INPUT'
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BUFFER = 'BUFFER'
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OUTPUT = 'OUTPUT'
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def defineCharacteristics(self):
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self.name, self.i18n_name = self.trAlgorithm('Voronoi polygons')
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self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools')
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self.addParameter(ParameterVector(self.INPUT,
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self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POINT]))
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self.addParameter(ParameterNumber(self.BUFFER,
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self.tr('Buffer region'), 0.0, 100.0, 0.0))
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self.addOutput(OutputVector(self.OUTPUT, self.tr('Voronoi polygons')))
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def processAlgorithm(self, progress):
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layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT))
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buf = self.getParameterValue(self.BUFFER)
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writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
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layer.pendingFields().toList(), QGis.WKBPolygon, layer.crs())
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inFeat = QgsFeature()
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outFeat = QgsFeature()
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extent = layer.extent()
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extraX = extent.height() * (buf / 100.0)
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extraY = extent.width() * (buf / 100.0)
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height = extent.height()
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width = extent.width()
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c = voronoi.Context()
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pts = []
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ptDict = {}
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ptNdx = -1
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features = vector.features(layer)
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for inFeat in features:
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geom = QgsGeometry(inFeat.geometry())
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point = geom.asPoint()
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x = point.x() - extent.xMinimum()
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y = point.y() - extent.yMinimum()
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pts.append((x, y))
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ptNdx += 1
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ptDict[ptNdx] = inFeat.id()
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if len(pts) < 3:
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raise GeoAlgorithmExecutionException(
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self.tr('Input file should contain at least 3 points. Choose '
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'another file and try again.'))
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uniqueSet = Set(item for item in pts)
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ids = [pts.index(item) for item in uniqueSet]
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sl = voronoi.SiteList([voronoi.Site(i[0], i[1], sitenum=j) for (j,
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i) in enumerate(uniqueSet)])
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voronoi.voronoi(sl, c)
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inFeat = QgsFeature()
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current = 0
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total = 100.0 / float(len(c.polygons))
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for (site, edges) in c.polygons.iteritems():
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request = QgsFeatureRequest().setFilterFid(ptDict[ids[site]])
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inFeat = layer.getFeatures(request).next()
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lines = self.clip_voronoi(edges, c, width, height, extent, extraX, extraY)
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geom = QgsGeometry.fromMultiPoint(lines)
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geom = QgsGeometry(geom.convexHull())
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outFeat.setGeometry(geom)
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outFeat.setAttributes(inFeat.attributes())
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writer.addFeature(outFeat)
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current += 1
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progress.setPercentage(int(current * total))
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del writer
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def clip_voronoi(self, edges, c, width, height, extent, exX, exY):
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"""Clip voronoi function based on code written for Inkscape.
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Copyright (C) 2010 Alvin Penner, penner@vaxxine.com
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"""
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def clip_line(x1, y1, x2, y2, w, h, x, y):
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if x1 < 0 - x and x2 < 0 - x:
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return [0, 0, 0, 0]
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if x1 > w + x and x2 > w + x:
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return [0, 0, 0, 0]
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if x1 < 0 - x:
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y1 = (y1 * x2 - y2 * x1) / (x2 - x1)
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x1 = 0 - x
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if x2 < 0 - x:
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y2 = (y1 * x2 - y2 * x1) / (x2 - x1)
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x2 = 0 - x
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if x1 > w + x:
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y1 = y1 + (w + x - x1) * (y2 - y1) / (x2 - x1)
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x1 = w + x
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if x2 > w + x:
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y2 = y1 + (w + x - x1) * (y2 - y1) / (x2 - x1)
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x2 = w + x
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if y1 < 0 - y and y2 < 0 - y:
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return [0, 0, 0, 0]
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if y1 > h + y and y2 > h + y:
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return [0, 0, 0, 0]
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if x1 == x2 and y1 == y2:
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return [0, 0, 0, 0]
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if y1 < 0 - y:
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x1 = (x1 * y2 - x2 * y1) / (y2 - y1)
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y1 = 0 - y
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if y2 < 0 - y:
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x2 = (x1 * y2 - x2 * y1) / (y2 - y1)
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y2 = 0 - y
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if y1 > h + y:
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x1 = x1 + (h + y - y1) * (x2 - x1) / (y2 - y1)
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y1 = h + y
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if y2 > h + y:
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x2 = x1 + (h + y - y1) * (x2 - x1) / (y2 - y1)
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y2 = h + y
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return [x1, y1, x2, y2]
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lines = []
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hasXMin = False
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hasYMin = False
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hasXMax = False
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hasYMax = False
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for edge in edges:
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if edge[1] >= 0 and edge[2] >= 0:
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# Two vertices
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[x1, y1, x2, y2] = clip_line(
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c.vertices[edge[1]][0],
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c.vertices[edge[1]][1],
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c.vertices[edge[2]][0],
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c.vertices[edge[2]][1],
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width,
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height,
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exX,
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exY,
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)
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elif edge[1] >= 0:
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# Only one vertex
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if c.lines[edge[0]][1] == 0:
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# Vertical line
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xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
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if c.vertices[edge[1]][1] > (height + exY) / 2:
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ytemp = height + exY
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else:
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ytemp = 0 - exX
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else:
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xtemp = width + exX
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ytemp = (c.lines[edge[0]][2] - (width + exX)
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* c.lines[edge[0]][0]) / c.lines[edge[0]][1]
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[x1, y1, x2, y2] = clip_line(
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c.vertices[edge[1]][0],
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c.vertices[edge[1]][1],
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xtemp,
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ytemp,
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width,
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height,
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exX,
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exY,
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)
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elif edge[2] >= 0:
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# Only one vertex
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if c.lines[edge[0]][1] == 0:
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# Vertical line
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xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
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if c.vertices[edge[2]][1] > (height + exY) / 2:
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ytemp = height + exY
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else:
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ytemp = 0.0 - exY
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else:
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xtemp = 0.0 - exX
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ytemp = c.lines[edge[0]][2] / c.lines[edge[0]][1]
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[x1, y1, x2, y2] = clip_line(
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xtemp,
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ytemp,
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c.vertices[edge[2]][0],
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c.vertices[edge[2]][1],
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width,
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height,
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exX,
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exY,
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)
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if x1 or x2 or y1 or y2:
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lines.append(QgsPoint(x1 + extent.xMinimum(), y1
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+ extent.yMinimum()))
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lines.append(QgsPoint(x2 + extent.xMinimum(), y2
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+ extent.yMinimum()))
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if 0 - exX in (x1, x2):
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hasXMin = True
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if 0 - exY in (y1, y2):
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hasYMin = True
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if height + exY in (y1, y2):
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hasYMax = True
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if width + exX in (x1, x2):
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hasXMax = True
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if hasXMin:
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if hasYMax:
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lines.append(QgsPoint(extent.xMinimum() - exX, height
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+ extent.yMinimum() + exY))
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if hasYMin:
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lines.append(QgsPoint(extent.xMinimum() - exX,
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extent.yMinimum() - exY))
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if hasXMax:
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if hasYMax:
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lines.append(QgsPoint(width + extent.xMinimum() + exX, height
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+ extent.yMinimum() + exY))
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if hasYMin:
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lines.append(QgsPoint(width + extent.xMinimum() + exX,
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extent.yMinimum() - exY))
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return lines
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