Création d'une ligne à partir d'une direction (en degrés) et d'une distance dans QGIS - Creating a line from a direction (in degrees) and a distance in QGIS (QGIS master with the new Python API)

line_from_pt_dist2.py

'''QGIS master with the new Python API
Martin Laloux 2013'''

from PyQt4.QtCore import *
from numpy import *

from PyQt4.QtCore import *
from numpy import *
a = QgsGeometry.fromPoint(QgsPoint(122.989235,13679.083853))

class distance(object):
       def __init__(self,a,angle,distance):
             self.a = a.asPoint()
             self.xori = self.a[0]
             self.yori = self.a[1]
             self.angle = angle
             self.distance = distance
             self.xfinal =0
             self.yfinal = 0
             self.dist_x = 0
             self.dist_y = 0
             self.fet = QgsFeature()
             self.vl = QgsVectorLayer("LineString", "temporary_lines", "memory")
             self.pr = self.vl.dataProvider()
             self.v2 = QgsVectorLayer("Point", "temporary_points", "memory")
       @property
       def resultat(self):
             self.dist_x, self.dist_y = (self.distance * sin(radians(self.angle)),self.distance * cos(radians(self.angle)))
             self.xfinal, self.yfinal = (self.xori + self.dist_x, self.yori + self.dist_y)
             return self.xfinal, self.yfinal
       @property
       def x(self):
             return self.resultat[0]
       @property
       def y(self):
             return self.resultat[1]
       @property
       def final(self):
             return QgsGeometry.fromPoint(QgsPoint(self.x,self.y))
       @property
       def trace(self):
             #self.vl
             fields = { 0 : QgsField("first", QVariant.Int) }
             #pr = vl.dataProvider()
             self.pr.addAttributes( [ QgsField("first", QVariant.Int)])
             self.fet.setGeometry(QgsGeometry.fromPolyline( [ QgsPoint(self.xori , self.yori ), QgsPoint(self.x, self.y) ] ))
             self.fet.setAttributeMap( { 0 : QVariant(1)} )
             self.pr.addFeatures( [ self.fet ] )
             self.vl.updateExtents()
             self.vl.updateFieldMap()
             QgsMapLayerRegistry.instance().addMapLayers([self.vl])
       @property
       def origine(self):
             self.pr = self.v2.dataProvider()
             self.fet = QgsFeature()
             self.pr.addAttributes( [ QgsField("statut", QVariant.String)] )
             self.fet.setGeometry( QgsGeometry.fromPoint(QgsPoint(self.xori,self.yori)) )
             self.fet.setAttributeMap( { 0 : QVariant("origine")} )
             self.pr.addFeatures( [ self.fet ] )
             self.v2.updateExtents()
             self.v2.updateFieldMap()
             QgsMapLayerRegistry.instance().addMapLayers([self.v2])
       @property
       def arrive(self):
             self.pr = self.v2.dataProvider()
             self.fet = QgsFeature()
             #self.pr.addAttributes( [ QgsField("statut", QVariant.String)] ) sinon 2 col
             self.fet.setGeometry( QgsGeometry.fromPoint(QgsPoint(self.x,self.y)) )
             self.fet.setAttributeMap( { 0 : QVariant("arrive")} )
             self.pr.addFeatures( [ self.fet ] )
             self.v2.updateExtents()
             self.v2.updateFieldMap()
             #QgsMapLayerRegistry.instance().addMapLayer(self.v2) # il faut chipoter pour arriver au résultat
             

>>> point_dep = QgsGeometry.fromPoint(QgsPoint(231009.737,110767.821))
>>> point_arriv = distance(point_dep, 20, 100)
>>> point_arriv.final
<qgis.core.QgsGeometry object at 0x12afd9200>
>>> point_arriv.resultat
(231043.93901433257, 110861.79026207859)
>>> point_arriv.x
231043.93901433257
>>> point_arriv.y
110861.79026207859
>>> point_arriv.trace
>>> point_arriv2 = distance(point_arriv.final, 80, 200)
>>> point_arriv2.x
231240.900564935
>>> point_arriv2.y
110896.51989761197
>>> point_arriv2.trace