map-machine/roentgen/direction.py
Sergey Vartanov cbbd7bcf05 Fix code style.
Fix some pylint warnings.
2021-05-07 00:57:05 +03:00

131 lines
3.5 KiB
Python

"""
Direction tag support.
Author: Sergey Vartanov (me@enzet.ru).
"""
from typing import Iterator, List, Optional, Union
import numpy as np
from portolan import middle
Path = Union[float, str, np.array]
SHIFT: float = -np.pi / 2
SMALLEST_ANGLE: float = np.pi / 15
DEFAULT_ANGLE: float = np.pi / 30
def degree_to_radian(degree: float) -> float:
""" Convert value in degrees to radians. """
return degree / 180 * np.pi
def parse_vector(text: str) -> Optional[np.array]:
"""
Parse vector from text representation: compass points or 360-degree
notation. E.g. "NW", "270".
:param text: vector text representation
:return: parsed normalized vector
"""
try:
radians: float = degree_to_radian(float(text)) + SHIFT
return np.array((np.cos(radians), np.sin(radians)))
except ValueError:
pass
try:
radians: float = degree_to_radian(middle(text)) + SHIFT
return np.array((np.cos(radians), np.sin(radians)))
except KeyError:
pass
return None
def rotation_matrix(angle) -> np.array:
"""
Get a matrix to rotate 2D vector by the angle.
:param angle: angle in radians
"""
return np.array([
[np.cos(angle), np.sin(angle)],
[-np.sin(angle), np.cos(angle)]])
class Sector:
"""
Sector described by two vectors.
"""
def __init__(self, text: str, angle: Optional[float] = None):
"""
:param text: sector text representation (e.g. "70-210", "N-NW")
:param angle: angle in degrees
"""
self.start: Optional[np.array] = None
self.end: Optional[np.array] = None
if "-" in text:
parts: List[str] = text.split("-")
self.start = parse_vector(parts[0])
self.end = parse_vector(parts[1])
else:
result_angle: float
if angle is None:
result_angle = DEFAULT_ANGLE
else:
result_angle = max(SMALLEST_ANGLE, degree_to_radian(angle) / 2)
vector: Optional[np.array] = parse_vector(text)
if vector is not None:
self.start = np.dot(rotation_matrix(result_angle), vector)
self.end = np.dot(rotation_matrix(-result_angle), vector)
def draw(self, center: np.array, radius: float) -> Optional[List[Path]]:
"""
Construct SVG path commands for arc element.
:param center: arc center point
:param radius: arc radius
:return: SVG path commands
"""
if self.start is None or self.end is None:
return None
start: np.array = center + radius * self.end
end: np.array = center + radius * self.start
return ["L", start, "A", radius, radius, 0, "0", 0, end]
def __str__(self) -> str:
return f"{self.start}-{self.end}"
class DirectionSet:
"""
Describes direction, set of directions.
"""
def __init__(self, text: str):
"""
:param text: direction tag value
"""
self.sectors: Iterator[Optional[Sector]] = map(Sector, text.split(";"))
def __str__(self) -> str:
return ", ".join(map(str, self.sectors))
def draw(self, center: np.array, radius: float) -> Iterator[List[Path]]:
"""
Construct SVG "d" for arc elements.
:param center: center point of all arcs
:param radius: radius of all arcs
:return: list of "d" values
"""
return filter(
lambda x: x is not None,
map(lambda x: x.draw(center, radius), self.sectors))