map-machine/map_machine/figure.py

"""Figures displayed on the map."""
import numpy as np

from map_machine.geometry.flinger import Flinger
from map_machine.osm.osm_reader import OSMNode, Tagged
from map_machine.scheme import LineStyle

__author__ = "Sergey Vartanov"
__email__ = "me@enzet.ru"

from map_machine.geometry.vector import Polyline


class Figure(Tagged):
    """Some figure on the map: way or area."""

    def __init__(
        self,
        tags: dict[str, str],
        inners: list[list[OSMNode]],
        outers: list[list[OSMNode]],
    ) -> None:
        super().__init__(tags)

        if inners and outers:
            self.inners: list[list[OSMNode]] = list(map(make_clockwise, inners))
            self.outers: list[list[OSMNode]] = list(
                map(make_counter_clockwise, outers)
            )
        else:
            self.inners = inners
            self.outers = outers

    def get_path(
        self, flinger: Flinger, offset: np.ndarray = np.array((0.0, 0.0))
    ) -> str:
        """
        Get SVG path commands.

        :param flinger: converter for geo coordinates
        :param offset: offset vector
        """
        path: str = ""

        for outer_nodes in self.outers:
            path += f"{get_path(outer_nodes, offset, flinger)} "

        for inner_nodes in self.inners:
            path += f"{get_path(inner_nodes, offset, flinger)} "

        return path


class StyledFigure(Figure):
    """Figure with stroke and fill style."""

    def __init__(
        self,
        tags: dict[str, str],
        inners: list[list[OSMNode]],
        outers: list[list[OSMNode]],
        line_style: LineStyle,
    ) -> None:
        super().__init__(tags, inners, outers)
        self.line_style: LineStyle = line_style

    def get_path(
        self,
        flinger: Flinger,
        offset: np.ndarray = np.array((0.0, 0.0)),
    ) -> str:
        """
        Get SVG path commands.

        :param flinger: converter for geo coordinates
        :param offset: offset vector
        """
        path: str = ""

        for outer_nodes in self.outers:
            commands: str = get_path(
                outer_nodes, offset, flinger, self.line_style.parallel_offset
            )
            path += f"{commands} "

        for inner_nodes in self.inners:
            commands: str = get_path(
                inner_nodes, offset, flinger, self.line_style.parallel_offset
            )
            path += f"{commands} "

        return path

    def get_layer(self) -> float:
        """
        Get figure layer value or 0 if it is not specified.

        TODO: support values separated by "," or ";".
        """
        try:
            if "layer" in self.tags:
                return float(self.tags["layer"])
        except ValueError:
            return 0.0
        return 0.0

    def __lt__(self, other: "StyledFigure") -> bool:
        """Compare figures based on priority and layer."""
        if self.get_layer() != other.get_layer():
            return self.get_layer() < other.get_layer()

        return self.line_style.priority < other.line_style.priority


def is_clockwise(polygon: list[OSMNode]) -> bool:
    """
    Return true if polygon nodes are in clockwise order.

    :param polygon: list of OpenStreetMap nodes
    """
    count: float = 0.0
    for index, node in enumerate(polygon):
        next_index: int = 0 if index == len(polygon) - 1 else index + 1
        count += (polygon[next_index].coordinates[0] - node.coordinates[0]) * (
            polygon[next_index].coordinates[1] + node.coordinates[1]
        )
    return count >= 0.0


def make_clockwise(polygon: list[OSMNode]) -> list[OSMNode]:
    """
    Make polygon nodes clockwise.

    :param polygon: list of OpenStreetMap nodes
    """
    return polygon if is_clockwise(polygon) else list(reversed(polygon))


def make_counter_clockwise(polygon: list[OSMNode]) -> list[OSMNode]:
    """
    Make polygon nodes counter-clockwise.

    :param polygon: list of OpenStreetMap nodes
    """
    return polygon if not is_clockwise(polygon) else list(reversed(polygon))


def get_path(
    nodes: list[OSMNode],
    shift: np.ndarray,
    flinger: Flinger,
    parallel_offset: float = 0.0,
) -> str:
    """Construct SVG path commands from nodes."""
    return Polyline(
        [flinger.fling(node.coordinates) + shift for node in nodes]
    ).get_path(parallel_offset)