r2point.py

from math import sqrt
from deq import Deq


class R2Point:
    """ Точка (Point) на плоскости (R2) """

    # Конструктор
    def __init__(self, x=None, y=None):
        if x is None:
            x = float(input("x -> "))
        if y is None:
            y = float(input("y -> "))
        self.x, self.y = x, y

    # Площадь треугольника
    @staticmethod
    def area(a, b, c):
        return 0.5 * ((a.x - c.x) * (b.y - c.y) - (a.y - c.y) * (b.x - c.x))

    # Лежат ли точки на одной прямой?
    @staticmethod
    def is_triangle(a, b, c):
        return R2Point.area(a, b, c) != 0.0

    # Расстояние до другой точки
    def dist(self, other):
        return sqrt((other.x - self.x)**2 + (other.y - self.y)**2)

    # Лежит ли точка внутри "стандартного" прямоугольника?
    def is_inside(self, a, b):
        return (((a.x <= self.x and self.x <= b.x) or
                 (a.x >= self.x and self.x >= b.x)) and
                ((a.y <= self.y and self.y <= b.y) or
                 (a.y >= self.y and self.y >= b.y)))

    # Освещено ли из данной точки ребро (a,b)?
    def is_light(self, a, b):
        s = R2Point.area(a, b, self)
        return s < 0.0 or (s == 0.0 and not self.is_inside(a, b))

    # Совпадает ли точка с другой?
    def __eq__(self, other):
        if isinstance(other, type(self)):
            return self.x == other.x and self.y == other.y
        return False

    # Пересечение двух отрезков
    @staticmethod
    def intersect(a, b, c, d):
        det = (b.x - a.x) * (c.y - d.y) - (c.x - d.x) * (b.y - a.y)
        if det == 0:

            return None

        else:
            x = ((c.x - a.x) * (c.y - d.y) - (c.x - d.x) * (c.y - a.y)) / det
            y = ((b.x - a.x) * (c.y - a.y) - (c.x - a.x) * (b.y - a.y)) / det
            if (0 <= x <= 1) and (0 <= y <= 1):

                return R2Point(a.x + (b.x - a.x) * x, a.y + (b.y - a.y) * x)
            else:
                return None

    def __repr__(self):
        return f"{self.x},{self.y}"