# -*- 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 qgis.core import QGis, QgsFeatureRequest, QgsFeature, QgsGeometry, QgsPoint from processing.core.GeoAlgorithm import GeoAlgorithm from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException from processing.core.parameters import ParameterVector from processing.core.parameters import ParameterNumber from processing.core.outputs import OutputVector import voronoi from processing.tools import dataobjects, vector class VoronoiPolygons(GeoAlgorithm): INPUT = 'INPUT' BUFFER = 'BUFFER' OUTPUT = 'OUTPUT' def defineCharacteristics(self): self.name = 'Voronoi polygons' self.group = 'Vector geometry tools' self.addParameter(ParameterVector(self.INPUT, self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POINT])) self.addParameter(ParameterNumber(self.BUFFER, self.tr('Buffer region'), 0.0, 100.0, 0.0)) self.addOutput(OutputVector(self.OUTPUT, self.tr('Voronoi polygons'))) def processAlgorithm(self, progress): layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT)) buf = self.getParameterValue(self.BUFFER) writer = self.getOutputFromName(self.OUTPUT).getVectorWriter( layer.pendingFields().toList(), QGis.WKBPolygon, layer.crs()) inFeat = QgsFeature() outFeat = QgsFeature() extent = layer.extent() extraX = extent.height() * (buf / 100.0) extraY = extent.width() * (buf / 100.0) 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( self.tr('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, extraX, extraY) 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