"Defines data types out of which line locations consist"
from typing import NamedTuple, Tuple, Optional, List
from shapely.geometry import LineString
from shapely.ops import substring
from openlr import Coordinates
from ..maps.abstract import Line, path_length
from ..maps.wgs84 import interpolate, split_line, join_lines
[docs]class PointOnLine(NamedTuple):
"A point on the road network"
#: The line element on which the point resides
line: Line
#: Specifies the relative offset of the point.
#: Its value is member of the interval [0.0, 1.0].
#: A value of 0 references the starting point of the line.
relative_offset: float
[docs] def position(self) -> Coordinates:
"Returns the actual geo position"
return interpolate(self.line.coordinates(), self.distance_from_start())
[docs] def distance_from_start(self) -> float:
"Returns the distance in meters from the start of the line to the point"
return self.relative_offset * self.line.length
[docs] def distance_to_end(self) -> float:
"Returns the distance in meters from the point to the end of the line"
return (1.0 - self.relative_offset) * self.line.length
[docs] def split(self) -> Tuple[Optional[LineString], Optional[LineString]]:
"Splits the Line element that this point is along and returns the parts"
return split_line(self.line.geometry, self.distance_from_start())
[docs] @classmethod
def from_abs_offset(cls, line: Line, meters_into: float):
"""Build a PointOnLine from an absolute offset value.
Negative offsets are recognized and subtracted."""
if meters_into >= 0.0:
return cls(line, meters_into / line.length)
else:
negative_meters_into = line.length + meters_into
return cls(line, negative_meters_into / line.length)
[docs]class Route(NamedTuple):
"A part of a line location path. May contain partial lines."
#: The point with which this location is starting
start: PointOnLine
#: While the first and the last line may be partial, these are the intermediate lines.
path_inbetween: List[Line]
#: The point on which this location is ending
end: PointOnLine
@property
def lines(self) -> List[Line]:
"Returns all lines that take part in the route"
result = [self.start.line]
for line in self.path_inbetween:
if line.line_id != result[-1].line_id:
result.append(line)
if self.end.line.line_id == result[-1].line_id:
result.pop()
result.append(self.end.line)
return result
[docs] def length(self) -> float:
"Length of this line location part in meters"
lines = self.lines
result = path_length(lines)
if self.start.relative_offset > 0.0:
result -= self.start.distance_from_start()
if self.end.relative_offset < 1.0:
result -= self.end.distance_to_end()
return result
@property
def absolute_start_offset(self) -> float:
"Offset on the starting line in meters"
return self.start.distance_from_start()
@property
def absolute_end_offset(self) -> float:
"Offset on the ending line in meters"
return self.end.distance_to_end()
@property
def shape(self) -> LineString:
"Returns the shape of the route. The route is has to be continuous."
if self.start.line.line_id == self.end.line.line_id:
return substring(
self.start.line.geometry,
self.start.relative_offset,
self.end.relative_offset,
normalized=True
)
result = []
first = self.start.split()[1]
last = self.end.split()[0]
if first is not None:
result.append(first)
result += [line.geometry for line in self.path_inbetween]
if last is not None:
result.append(last)
return join_lines(result)
[docs] def coordinates(self) -> List[Coordinates]:
"Returns all Coordinates of this line location"
return [Coordinates(lon, lat) for (lon, lat) in self.shape.coords]