Files

151 lines
4.8 KiB
Python

# tools/geometry.py
from dataclasses import dataclass
import math
@dataclass
class Point:
"""Represents a 2D point in a Cartesian coordinate system."""
x: float
y: float
class Line:
"""Represents a finite line segment between two Points."""
def __init__(self, p1: Point, p2: Point) -> None:
self.p1 = p1
self.p2 = p2
def distance_to_point(self, point: Point) -> float:
"""
Calculates the shortest distance from this line segment to a given point.
Uses vector projection to find the closest point on the segment.
"""
x1, y1 = self.p1.x, self.p1.y
x2, y2 = self.p2.x, self.p2.y
x3, y3 = point.x, point.y
# If the line is actually just a single point
if x1 == x2 and y1 == y2:
return ((x1 - x3) ** 2 + (y1 - y3) ** 2) ** 0.5
px, py = x2 - x1, y2 - y1
norm = px * px + py * py
# Calculate the projection scalar (u) of the point onto the line
u = ((x3 - x1) * px + (y3 - y1) * py) / float(norm)
# Clamp u to the [0, 1] range to ensure we stay on the line segment
u = max(0.0, min(1.0, u))
# Find the exact coordinates of the closest point on the segment
closest_x = x1 + u * px
closest_y = y1 + u * py
# Return distance from the target point to the closest point
dx, dy = closest_x - x3, closest_y - y3
return (dx * dx + dy * dy) ** 0.5
class LineString:
"""Represents a path formed by a sequence of connected line segments."""
def __init__(self, lines: list[list[float]]) -> None:
if len(lines) < 2:
raise ValueError("A LineString requires at least 2 coordinate pairs.")
self.lineList: list[Line] = []
for i in range(len(lines) - 1):
p1 = Point(lines[i][0], lines[i][1])
p2 = Point(lines[i + 1][0], lines[i + 1][1])
self.lineList.append(Line(p1, p2))
def distance_to(self, point: Point) -> float:
"""Calculates the minimum distance from the given point to the LineString."""
# Cleanly check the distance to all segments and return the smallest one
return min(line.distance_to_point(point) for line in self.lineList)
def is_intersecting(self, point: Point) -> bool:
"""Checks if a given point lies exactly on the LineString (with tolerance)."""
return math.isclose(self.distance_to(point), 0.0, abs_tol=1e-9)
class Polygon:
"""Represents a 2D shape enclosed by a series of connected points."""
def __init__(self, points: list[list[float]]) -> None:
self.listPoints: list[Point] = [Point(p[0], p[1]) for p in points]
def contains(self, p: Point) -> bool:
"""
Determines if a point is inside the Polygon using the Even-Odd rule.
Includes an explicit check for points lying exactly on the boundary edges.
"""
n = len(self.listPoints)
if n < 3:
return False
inside = False
j = n - 1
for i in range(n):
pi = self.listPoints[i]
pj = self.listPoints[j]
cross_product = (p.y - pi.y) * (pj.x - pi.x) - (p.x - pi.x) * (pj.y - pi.y)
if math.isclose(cross_product, 0.0, abs_tol=1e-9):
if min(pi.x, pj.x) <= p.x <= max(pi.x, pj.x) and min(
pi.y, pj.y
) <= p.y <= max(pi.y, pj.y):
return True
if ((pi.y > p.y) != (pj.y > p.y)) and (
p.x < (pj.x - pi.x) * (p.y - pi.y) / (pj.y - pi.y) + pi.x
):
inside = not inside
j = i
return inside
class MultiPolygon:
"""Represents a collection of multiple separate Polygons."""
def __init__(self, polygons: list) -> None:
self.listPolygons: list[Polygon] = [Polygon(polygon[0]) for polygon in polygons]
def contains(self, p: Point) -> bool:
"""Returns True if the point is inside ANY of the contained Polygons."""
for polygon in self.listPolygons:
if polygon.contains(p):
return True
return False
@dataclass
class Coordinate:
"""
Custom type for the management of geographical coordinates.
Provides utility to switch between lat/long and x/y point spaces.
"""
lat: float
long: float
@property
def tuple(self) -> tuple[float, float]:
"""Returns the coordinates as a (Latitude, Longitude) tuple."""
return (self.lat, self.long)
def to_Point(self, reversed: bool = False) -> Point:
"""
Returns Coordinates mapped to a Cartesian Point.
Args:
reversed (bool): If True, switches orientation so x=long, y=lat.
Defaults to False (x=lat, y=long).
"""
return Point(self.long, self.lat) if reversed else Point(self.lat, self.long)