Python osgeo.ogr 模块，wkbLineString() 实例源码

def SetZ (poGeom, dfZ ):

    if poGeom is None:
        return

    eGType = wkbFlatten(poGeom.GetGeometryType())
    if eGType == ogr.wkbPoint:
        poGeom.SetPoint(0, poGeom.GetX(), poGeom.GetY(), dfZ)

    elif eGType == ogr.wkbLineString or \
         eGType == ogr.wkbLinearRing:
        for i in range(poGeom.GetPointCount()):
            poGeom.SetPoint(i, poGeom.GetX(i), poGeom.GetY(i), dfZ)

    elif eGType == ogr.wkbPolygon or \
         eGType == ogr.wkbMultiPoint or \
         eGType == ogr.wkbMultiLineString or \
         eGType == ogr.wkbMultiPolygon or \
         eGType == ogr.wkbGeometryCollection:
        for i in range(poGeom.GetGeometryCount()):
            SetZ(poGeom.GetGeometryRef(i), dfZ)

#**********************************************************************
#                         SetupTargetLayer()
#**********************************************************************

def SetZ (poGeom, dfZ ):

    if poGeom is None:
        return

    eGType = wkbFlatten(poGeom.GetGeometryType())
    if eGType == ogr.wkbPoint:
        poGeom.SetPoint(0, poGeom.GetX(), poGeom.GetY(), dfZ)

    elif eGType == ogr.wkbLineString or \
         eGType == ogr.wkbLinearRing:
        for i in range(poGeom.GetPointCount()):
            poGeom.SetPoint(i, poGeom.GetX(i), poGeom.GetY(i), dfZ)

    elif eGType == ogr.wkbPolygon or \
         eGType == ogr.wkbMultiPoint or \
         eGType == ogr.wkbMultiLineString or \
         eGType == ogr.wkbMultiPolygon or \
         eGType == ogr.wkbGeometryCollection:
        for i in range(poGeom.GetGeometryCount()):
            SetZ(poGeom.GetGeometryRef(i), dfZ)

#/************************************************************************/
#/*                         SetupTargetLayer()                           */
#/************************************************************************/

def _get_vector_attributes(self,ds,attrs):
        logging.debug("[FileMan][_get_vector_attributes]")

        layer = ds.GetLayer()

        # extent
        extent = layer.GetExtent()
        logging.debug("[FileMan][_get_vector_attributes] Extent: %s" % repr(extent) )
        attrs["extent"] = (extent[0],extent[2],extent[1],extent[3])

        # features count
        attrs["features_count"] = layer.GetFeatureCount()

        # geom type
        ftype = layer.GetGeomType()
        if ftype == ogr.wkbPolygon:    #3
            attrs["type"] = "polygon"
        elif ftype == ogr.wkbPoint:    #1
            attrs["type"] = "point"
        elif ftype == ogr.wkbLineString:   #2
            attrs["type"] = "line"
        elif ftype == ogr.wkbPolygon25D:
            attrs["type"] = "polygon"
        else: 
            attrs["type"] = "none/unknown"  # 0 or anything else

        # srs
        sr = layer.GetSpatialRef()
        logging.debug("[FileMan][_get_vector_attributes] Spatial Reference from layer.GetSpatialRef() : %s" % repr(sr) )
        if sr:
            attrs["prj"]= self._get_prj(sr)
        else:
            attrs["prj"] = "unknown"

        # Done
        return attrs

def DumpReadableGeometry( poGeometry, pszPrefix, options ):

    if pszPrefix == None:
        pszPrefix = ""

    if 'DISPLAY_GEOMETRY' in options and EQUAL(options['DISPLAY_GEOMETRY'], 'SUMMARY'):

        line = ("%s%s : " % (pszPrefix, poGeometry.GetGeometryName() ))
        eType = poGeometry.GetGeometryType()
        if eType == ogr.wkbLineString or eType == ogr.wkbLineString25D:
            line = line + ("%d points" % poGeometry.GetPointCount())
            print(line)
        elif eType == ogr.wkbPolygon or eType == ogr.wkbPolygon25D:
            nRings = poGeometry.GetGeometryCount()
            if nRings == 0:
                line = line + "empty"
            else:
                poRing = poGeometry.GetGeometryRef(0)
                line = line + ("%d points" % poRing.GetPointCount())
                if nRings > 1:
                    line = line + (", %d inner rings (" % (nRings - 1))
                    for ir in range(0,nRings-1):
                        if ir > 0:
                            line = line + ", "
                        poRing = poGeometry.GetGeometryRef(ir+1)
                        line = line + ("%d points" % poRing.GetPointCount())
                    line = line + ")"
            print(line)

        elif eType == ogr.wkbMultiPoint or \
            eType == ogr.wkbMultiPoint25D or \
            eType == ogr.wkbMultiLineString or \
            eType == ogr.wkbMultiLineString25D or \
            eType == ogr.wkbMultiPolygon or \
            eType == ogr.wkbMultiPolygon25D or \
            eType == ogr.wkbGeometryCollection or \
            eType == ogr.wkbGeometryCollection25D:

                line = line + "%d geometries:" % poGeometry.GetGeometryCount()
                print(line)
                for ig in range(poGeometry.GetGeometryCount()):
                    subgeom = poGeometry.GetGeometryRef(ig)
                    from sys import version_info
                    if version_info >= (3,0,0):
                        exec('print("", end=" ")')
                    else:
                        exec('print "", ')
                    DumpReadableGeometry( subgeom, pszPrefix, options)
        else:
            print(line)

    elif 'DISPLAY_GEOMETRY' not in options or EQUAL(options['DISPLAY_GEOMETRY'], 'yes') \
            or EQUAL(options['DISPLAY_GEOMETRY'], 'WKT'):

        print("%s%s" % (pszPrefix, poGeometry.ExportToWkt() ))

    return

def _create_layer(self, type, srid, attributes, title):
        """
        Creates an empty spatialite layer
        :param type: 'Point', 'LineString', 'Polygon', etc.
        :param srid: CRS ID of the layer
        :param attributes: list of (attribute_name, attribute_type, attribute_typename)
        :param title: title of the layer
        """
        driver = ogr.GetDriverByName('GPKG')
        ds = driver.CreateDataSource(self.output_local_file)
        layer = ds.CreateLayer("meta", geom_type = ogr.wkbNone)
        layer.CreateField(ogr.FieldDefn('key', ogr.OFTString))
        layer.CreateField(ogr.FieldDefn('value', ogr.OFTString))

        if srid:
            wkbType = { 'point': ogr.wkbPoint,
                        'multipoint': ogr.wkbMultiPoint,
                        'linestring': ogr.wkbLineString,
                        'multilinestring': ogr.wkbMultiLineString,
                        'polygon': ogr.wkbPolygon,
                        'multipolygon': ogr.wkbMultiPolygon
            }[type]
            srs = osr.SpatialReference()
            srs.ImportFromEPSGA(int(srid))
        else:
            wkbType = ogr.wkbNone
            srs = None
        layer = ds.CreateLayer("data", srs, wkbType, ['FID=id'])
        layer.CreateField(ogr.FieldDefn('id', ogr.OFTInteger64))
        layer.CreateField(ogr.FieldDefn('fid', ogr.OFTString))
        layer.CreateField(ogr.FieldDefn('_xml_', ogr.OFTString))

        att_type_map = {QVariant.String : ogr.OFTString,
                        QVariant.Int : ogr.OFTInteger,
                        QVariant.Double: ogr.OFTReal,
                        QVariant.DateTime: ogr.OFTDateTime}
        for aname, atype in attributes:
            layer.CreateField(ogr.FieldDefn(aname, att_type_map[atype]))

        # update fields
        layer.ResetReading()

        qgs_layer = QgsVectorLayer("{}|layername=data".format(self.output_local_file), title, "ogr")
        return qgs_layer