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1
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def delaunay_triangulation( self ):
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2
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import voronoi
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3
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4
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ptDict = {}
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5
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ptNdx = -1
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6
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7
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vprovider = self.vlayer.dataProvider()
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8
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allAttrs = vprovider.attributeIndexes()
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9
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vprovider.select( allAttrs )
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10
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fields = {
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11
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0 : QgsField( "POINTA", QVariant.Double ),
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12
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1 : QgsField( "POINTB", QVariant.Double ),
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13
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2 : QgsField( "POINTC", QVariant.Double ) }
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14
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writer = QgsVectorFileWriter( self.myName, self.myEncoding,
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15
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fields, QGis.WKBPolygon, vprovider.crs() )
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16
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inFeat = QgsFeature()
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17
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points = []
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18
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while vprovider.nextFeature( inFeat ):
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19
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inGeom = QgsGeometry( inFeat.geometry() )
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20
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point = inGeom.asPoint()
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21
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points.append( point )
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22
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23
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ptNdx +=1
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24
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ptDict[ptNdx] = inFeat.id()
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25
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26
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vprovider.rewind()
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27
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vprovider.select( allAttrs )
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28
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triangles = voronoi.computeDelaunayTriangulation( points )
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29
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feat = QgsFeature()
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30
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nFeat = len( triangles )
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31
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nElement = 0
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32
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self.emit( SIGNAL( "runStatus(PyQt_PyObject)" ), 0 )
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33
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self.emit( SIGNAL( "runRange(PyQt_PyObject)" ), ( 0, nFeat ) )
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34
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for triangle in triangles:
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35
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indicies = list( triangle )
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36
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indicies.append( indicies[ 0 ] )
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37
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polygon = []
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38
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step = 0
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39
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for index in indicies:
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40
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41
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vprovider.featureAtId( ptDict[index], inFeat, True, allAttrs )
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42
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43
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geom = QgsGeometry( inFeat.geometry() )
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44
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point = QgsPoint( geom.asPoint() )
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45
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polygon.append( point )
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46
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if step <= 3: feat.addAttribute( step, QVariant( index ) )
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47
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step += 1
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48
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geometry = QgsGeometry().fromPolygon( [ polygon ] )
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49
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feat.setGeometry( geometry )
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50
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writer.addFeature( feat )
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51
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nElement += 1
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52
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self.emit( SIGNAL( "runStatus(PyQt_PyObject)" ), nElement )
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53
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del writer
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54
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return True
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