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479 lines
20 KiB
Python
Executable File
479 lines
20 KiB
Python
Executable File
# -*- 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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__authors__ = 'Victor Olaya, Håvard Tveite'
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__date__ = 'August 2012'
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__copyright__ = '(C) 2012, Victor Olaya'
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import os
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from qgis.PyQt.QtGui import QIcon
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from qgis.core import (QgsApplication,
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QgsFeatureRequest,
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QgsFeatureSink,
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QgsFeature,
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QgsGeometry,
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QgsPointXY,
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QgsWkbTypes,
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QgsProcessing,
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QgsProcessingException,
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QgsProcessingParameterFeatureSource,
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QgsProcessingParameterFeatureSink,
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QgsProcessingParameterNumber)
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from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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from . import voronoi
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pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
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class VoronoiPolygons(QgisAlgorithm):
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INPUT = 'INPUT'
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BUFFER = 'BUFFER'
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OUTPUT = 'OUTPUT'
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def icon(self):
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return QgsApplication.getThemeIcon("/algorithms/mAlgorithmVoronoi.svg")
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def svgIconPath(self):
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return QgsApplication.iconPath("/algorithms/mAlgorithmVoronoi.svg")
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def group(self):
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return self.tr('Vector geometry')
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def groupId(self):
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return 'vectorgeometry'
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def __init__(self):
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super().__init__()
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def initAlgorithm(self, config=None):
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self.addParameter(
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QgsProcessingParameterFeatureSource(
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self.INPUT, self.tr('Input layer'),
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[QgsProcessing.TypeVectorPoint]))
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self.addParameter(
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QgsProcessingParameterNumber(
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self.BUFFER, self.tr('Buffer region (% of extent)'),
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minValue=0.0, defaultValue=0.0))
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self.addParameter(
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QgsProcessingParameterFeatureSink(
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self.OUTPUT, self.tr('Voronoi polygons'),
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type=QgsProcessing.TypeVectorPolygon))
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def name(self):
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return 'voronoipolygons'
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def displayName(self):
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return self.tr('Voronoi polygons')
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def tags(self):
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return self.tr('thiessen').split(',')
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def processAlgorithm(self, parameters, context, feedback):
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source = self.parameterAsSource(parameters, self.INPUT, context)
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if source is None:
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raise QgsProcessingException(
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self.invalidSourceError(parameters, self.INPUT))
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buf = self.parameterAsDouble(parameters, self.BUFFER, context)
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(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT,
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context, source.fields(),
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QgsWkbTypes.Polygon,
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source.sourceCrs())
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if sink is None:
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raise QgsProcessingException(
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self.invalidSinkError(parameters, self.OUTPUT))
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outFeat = QgsFeature()
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extent = source.sourceExtent()
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extraX = extent.width() * (buf / 100.0)
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# Adjust the extent
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extent.setXMinimum(extent.xMinimum() - extraX)
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extent.setXMaximum(extent.xMaximum() + extraX)
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extraY = extent.height() * (buf / 100.0)
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extent.setYMinimum(extent.yMinimum() - extraY)
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extent.setYMaximum(extent.yMaximum() + extraY)
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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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# Find the minimum and maximum x and y for the input points
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xmin = width
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xmax = 0
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ymin = height
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ymax = 0
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features = source.getFeatures()
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total = 100.0 / source.featureCount() if source.featureCount() else 0
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for current, inFeat in enumerate(features):
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if feedback.isCanceled():
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break
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geom = 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 x < xmin:
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xmin = x
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if y < ymin:
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ymin = y
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if x > xmax:
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xmax = x
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if y > ymax:
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ymax = y
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feedback.setProgress(int(current * total))
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if xmin == xmax or ymin == ymax:
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raise QgsProcessingException('The extent of the input points is '
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'not a polygon (all the points are '
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'on a vertical or horizontal line) '
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'- cannot make a Voronoi diagram!')
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xyminmax = [xmin, ymin, xmax, ymax]
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if len(pts) < 3:
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raise QgsProcessingException(
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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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# Eliminate duplicate points
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uniqueSet = set(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)
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for (j, i) in enumerate(uniqueSet)])
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voronoi.voronoi(sl, c)
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if len(c.polygons) == 0:
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raise QgsProcessingException(
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self.tr('There were no polygons created.'))
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inFeat = QgsFeature()
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current = 0
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total = 100.0 / len(c.polygons)
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# Clip each of the generated "polygons"
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for (site, edges) in list(c.polygons.items()):
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if feedback.isCanceled():
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break
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request = QgsFeatureRequest().setFilterFid(ptDict[ids[site]])
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inFeat = next(source.getFeatures(request))
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boundarypoints = self.clip_voronoi(edges, c, width,
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height, extent,
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inFeat.geometry().asPoint(),
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xyminmax)
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ptgeom = QgsGeometry.fromMultiPointXY(boundarypoints)
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geom = QgsGeometry(ptgeom.convexHull())
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outFeat.setGeometry(geom)
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outFeat.setAttributes(inFeat.attributes())
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sink.addFeature(outFeat, QgsFeatureSink.FastInsert)
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current += 1
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feedback.setProgress(int(current * total))
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return {self.OUTPUT: dest_id}
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def clip_voronoi(self, edges, c, width, height, extent, point, xyminmax):
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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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Clips one Thiessen polygon (convex polygon) to extent
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"""
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pt_x = point.x() - extent.xMinimum()
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pt_y = point.y() - extent.yMinimum()
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(xmin, ymin, xmax, ymax) = xyminmax
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def isclose(a, b, rel_tol=1e-9, abs_tol=0.0):
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return abs(a - b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
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def clip_line(x1, y1, x2, y2, w, h):
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if x1 < 0 and x2 < 0:
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# Completely to the left
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return [0, 0, 0, 0]
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if x1 > w and x2 > w:
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# Completely to the right
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return [0, 0, 0, 0]
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if y1 < 0 and y2 < 0:
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# Completely below
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return [0, 0, 0, 0]
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if y1 > h and y2 > h:
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# Completely above
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return [0, 0, 0, 0]
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# Clip on the left envelope boundary
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if x1 < 0:
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# First point to the left
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y1 = (y1 * x2 - y2 * x1) / (x2 - x1)
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x1 = 0
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if x2 < 0:
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# Last point to the left
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y2 = (y1 * x2 - y2 * x1) / (x2 - x1)
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x2 = 0
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# Clip on the right envelope boundary
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if x1 > w:
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# First point to the right
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y1 = y1 + (w - x1) * (y2 - y1) / (x2 - x1)
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x1 = w
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if x2 > w:
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# Last point to the right
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y2 = y1 + (w - x1) * (y2 - y1) / (x2 - x1)
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x2 = w
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if isclose(x1, x2) and isclose(y1, y2):
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return [0, 0, 0, 0]
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# Clip on the bottom envelope boundary
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if y1 < 0:
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# First point below
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x1 = (x1 * y2 - x2 * y1) / (y2 - y1)
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y1 = 0
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if y2 < 0:
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# Second point below
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x2 = (x1 * y2 - x2 * y1) / (y2 - y1)
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y2 = 0
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# Clip on the top envelope boundary
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if y1 > h:
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# First point above
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x1 = x1 + (h - y1) * (x2 - x1) / (y2 - y1)
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y1 = h
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if y2 > h:
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# Second point above
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x2 = x1 + (h - y1) * (x2 - x1) / (y2 - y1)
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y2 = h
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if isclose(x1, x2) and isclose(y1, y2):
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return [0, 0, 0, 0]
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return [x1, y1, x2, y2]
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bndpoints = []
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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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XMinNumber = 0
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XMaxNumber = 0
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YMinNumber = 0
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YMaxNumber = 0
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# The same line may appear twice for collinear input points,
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# so have to remember which lines have contributed
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XMinLine = -1
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XMaxLine = -1
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YMinLine = -1
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YMaxLine = -1
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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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)
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elif edge[1] >= 0:
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# Only one (left) 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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xtemp = c.vertices[edge[1]][0]
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ytemp = 0 - 1
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# if c.vertices[edge[1]][1] > height / 2:
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# ytemp = height
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# else:
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# ytemp = 0
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else:
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# Create an end of the line at the right edge - OK
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xtemp = width
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ytemp = (c.lines[edge[0]][2] - width *
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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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)
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elif edge[2] >= 0:
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# Only one (right) 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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xtemp = c.vertices[edge[2]][0]
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ytemp = height + 1
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# if c.vertices[edge[2]][1] > height / 2:
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# ytemp = height
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# else:
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# ytemp = 0.0
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else:
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# End the line at the left edge - OK
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xtemp = 0.0
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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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)
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else:
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# No vertex, only a line
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if c.lines[edge[0]][1] == 0:
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# Vertical line - should not happen
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xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
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ytemp = 0.0
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xend = xtemp
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yend = height
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else:
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# End the line at both edges - ???
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xtemp = 0.0
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ytemp = c.lines[edge[0]][2] / c.lines[edge[0]][1]
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xend = width
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yend = (c.lines[edge[0]][2] - width *
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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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xtemp,
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ytemp,
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xend,
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yend,
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width,
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height,
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)
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if x1 or x2 or y1 or y2:
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bndpoints.append(QgsPointXY(x1 + extent.xMinimum(),
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y1 + extent.yMinimum()))
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bndpoints.append(QgsPointXY(x2 + extent.xMinimum(),
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y2 + extent.yMinimum()))
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if 0 in (x1, x2):
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hasXMin = True
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if XMinLine != edge[0]:
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XMinNumber = XMinNumber + 1
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XMinLine = edge[0]
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if 0 in (y1, y2):
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hasYMin = True
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if YMinLine != edge[0]:
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YMinNumber = YMinNumber + 1
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YMinLine = edge[0]
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if height in (y1, y2):
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hasYMax = True
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if YMaxLine != edge[0]:
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YMaxNumber = YMaxNumber + 1
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YMaxLine = edge[0]
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if width in (x1, x2):
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hasXMax = True
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if XMaxLine != edge[0]:
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XMaxNumber = XMaxNumber + 1
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XMaxLine = edge[0]
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# Add auxiliary points for corner cases, if necessary (duplicate
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# points is not a problem - will be ignored later).
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# a) Extreme input points (lowest, leftmost, rightmost, highest)
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# A point can be extreme on both axis
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if pt_x == xmin: # leftmost point
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if XMinNumber == 0:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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extent.yMinimum()))
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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height + extent.yMinimum()))
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elif XMinNumber == 1:
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if hasYMin:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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extent.yMinimum()))
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elif hasYMax:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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height + extent.yMinimum()))
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elif pt_x == xmax: # rightmost point
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if XMaxNumber == 0:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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extent.yMinimum()))
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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height + extent.yMinimum()))
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elif XMaxNumber == 1:
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if hasYMin:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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extent.yMinimum()))
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elif hasYMax:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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height + extent.yMinimum()))
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if pt_y == ymin: # lowest point
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if YMinNumber == 0:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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extent.yMinimum()))
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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extent.yMinimum()))
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elif YMinNumber == 1:
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if hasXMin:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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extent.yMinimum()))
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elif hasXMax:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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extent.yMinimum()))
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elif pt_y == ymax: # highest point
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if YMaxNumber == 0:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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height + extent.yMinimum()))
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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height + extent.yMinimum()))
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elif YMaxNumber == 1:
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if hasXMin:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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height + extent.yMinimum()))
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elif hasXMax:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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height + extent.yMinimum()))
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# b) Polygon that covers the x or the y extent:
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if hasYMin and hasYMax:
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if YMaxNumber > 1:
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if hasXMin:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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extent.yMinimum()))
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elif hasXMax:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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extent.yMinimum()))
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elif YMinNumber > 1:
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if hasXMin:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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height + extent.yMinimum()))
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elif hasXMax:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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height + extent.yMinimum()))
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elif hasXMin and hasXMax:
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if XMaxNumber > 1:
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if hasYMin:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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extent.yMinimum()))
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elif hasYMax:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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extent.yMinimum()))
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elif XMinNumber > 1:
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if hasYMin:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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height + extent.yMinimum()))
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elif hasYMax:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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height + extent.yMinimum()))
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# c) Simple corners:
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if XMinNumber == 1 and YMinNumber == 1 and not hasXMax and not hasYMax:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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extent.yMinimum()))
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if XMinNumber == 1 and YMaxNumber == 1 and not hasXMax and not hasYMin:
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bndpoints.append(QgsPointXY(extent.xMinimum(),
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height + extent.yMinimum()))
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if XMaxNumber == 1 and YMinNumber == 1 and not hasXMin and not hasYMax:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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extent.yMinimum()))
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if XMaxNumber == 1 and YMaxNumber == 1 and not hasXMin and not hasYMin:
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bndpoints.append(QgsPointXY(width + extent.xMinimum(),
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height + extent.yMinimum()))
|
|
return bndpoints
|