satie_lab8_8_matplotlib

from pprint import pprint

import numpy as np
import matplotlib.pyplot as plt


def cast_line(h, r1, r2):
    # Кастим прямую с углом наклона tan(h), которая
    # исходит из точки (r1, r2)
    k = np.round(np.tan(h), K)
    return k, -k*r1+r2


def intersection(y1, y2):
    k1, b1 = y1
    k2, b2 = y2
    if k1 == k2: return None

    x = np.round((b2-b1) / (k1-k2), K)
    y = np.round(k1*x + b1, K)
    return x, y


def dist(x1, y1, x2, y2):
    return np.round(np.sqrt((x1-x2)**2 + (y1-y2)**2), K)


def get_all_intersections(all_lines, cur_line):
    intrs = []
    for line in all_lines:
        p = intersection(line, cur_line)
        if p: intrs.append((p, line))
    return intrs


def get_first_near_intersections(lines, cur_line, initial_point):
    x0, y0 = initial_point
    intrs = get_all_intersections(lines, cur_line)
    min_forward = [1e9, (), ()]
    min_backward = [1e9, (), ()]
    for p, line in intrs:
        x1, y1 = p
        t = [dist(x0, y0, x1, y1), line, p]
        if (x0 == x1 and y0 <= y1) or (x0 <= x1 and y0 == y1) or x0 <= x1:
            min_forward = min(min_forward, t, key=lambda x: x[0])
        else:
            min_backward = min(min_backward, t, key=lambda x: x[0])
    if not all(min_backward) or not all(min_forward):
        print(f'A({x}, {y}) не находится в каком-либо многоугольнике!')
        plot_graphic()
        raise SystemExit(1)
    return min_forward, min_backward

def plot_graphic(spec_lines=[]):
    fig = plt.figure()
    ax = fig.add_subplot(1, 1, 1)
    ox = np.linspace(r1, r2, n)
    ax.spines['left'].set_position('center')
    ax.spines['bottom'].set_position('center')
    ax.spines['right'].set_color('none')
    ax.spines['top'].set_color('none')
    ax.xaxis.set_ticks_position('bottom')
    ax.yaxis.set_ticks_position('left')
    plt.xlim(r1, r2)
    plt.ylim(r1, r2)
    plt.plot(x, y, marker='o', markersize=5, markerfacecolor='red', label=f'A({np.round(x, 2)}, {np.round(y, 2)})')
    for line in lines:
        k, b = line
        plt.plot(ox, k*ox + b, '--g')
    for line in spec_lines:
        k, b = line
        plt.plot(ox, k*ox + b, '-b', label=f'y={np.round(k, 2)}x + {np.round(b, 2)}')
    plt.legend(loc='upper left')
    plt.show()

n = 20
r1, r2 = -10, 10
k = (r2-r1) * np.random.sample(n) + r1
b = (r2-r1) * np.random.sample(n) + r1
lines = list(zip(k, b))

x, y = (r2-r1) * np.random.sample(2) + r1
K = 16
h = 0.01
vertexes = set()
main_lines = set()
for i in np.arange(-np.pi/2+h, np.pi/2-h, h):
    cur_line = cast_line(i, x, y)
    forward_result, backward_result = get_first_near_intersections(lines, cur_line, (x, y))
    for result in (forward_result, backward_result):
        _, line, intr = result
        forward_result2, backward_result2 = get_first_near_intersections(lines, line, intr)
        for second_result in (forward_result2, backward_result2):
            _, _, vertex = second_result
            _x, _y = vertex
            _x = np.round(_x, K//2)
            _y = np.round(_y, K//2)
            vertexes.add((_x, _y))
            main_lines.add(line)

print(f'Вершины многоугольника, которому принадлежит начальная точка A({x}, {y})')
pprint(vertexes)
plot_graphic(list(main_lines))