Generates points and creates their convex hull with the option to do if for all the points generated

convex_hull.py

from operator import itemgetter
from python.common import line as ln
from python.common.polygon import Polygon
from python.common.svg import Svg
from python.less5.generate_points import generate_points


def less(a, b):
    return a < b


def more(a, b):
    return a > b


def get_hull_points(hull_points, all_points, left_to_right):
    offset = 180 if left_to_right else 360
    compare_fn = less if left_to_right else more
    for point in hull_points:
        ln1 = ln.Line(point[0], point[1], point[0], point[1] + 1)
        true_next = None
        angle_min = None
        for next_p in all_points:
            if compare_fn(next_p[0], point[0]):
                continue

            ln2 = ln.Line(point[0], point[1], next_p[0], next_p[1])
            angle = ln.line_angle(ln1, ln2, offset)
            if angle_min is None or compare_fn(angle_min, angle):
                angle_min = angle
                true_next = next_p

        if true_next is None:
            break
        all_points.remove(true_next)
        hull_points.append(true_next)
    return hull_points


def convex_hull(number_of_points, canvas_size, onion=False, gauss=False):
    svg = Svg()
    points = generate_points(number_of_points, canvas_size, gauss)

    for point in points:
        svg.add_circle(point)

    run_length = len(points) if onion else 1

    while run_length > 0:
        points_on_x = sorted(points, key=itemgetter(0))
        leftmost_p = points_on_x[0]
        rightmost_p = points_on_x[-1]

        svg.add_circle(leftmost_p, fill_color=(255, 0, 0), stroke_width=0.25, r=1)
        svg.add_circle(rightmost_p, fill_color=(255, 0, 0), stroke_width=0.25, r=1)

        hull_points_1 = get_hull_points([leftmost_p], points, True)
        hull_points_2 = get_hull_points([rightmost_p], points, False)

        hull_points = hull_points_1 + hull_points_2

        hull_points.append(hull_points[0])
        polygon = Polygon(hull_points)
        polygon.draw_to_svg(svg)

        points = [x for x in points if x not in hull_points]
        run_length = len(points) if onion else 0

    svg.save("convex_hull" + ("_onion" if onion else "") +
             ("_gauss" if gauss else ""))

# convex_hull(1000, (1920, 1060), onion=True, gauss=False) # Obr. 1
# convex_hull(1000, (1920, 1060), onion=True, gauss=True) # Obr. 2
# convex_hull(1000, (1920, 1060), onion=False, gauss=False) # Obr. 3
# convex_hull(1000, (1920, 1060), onion=False, gauss=True) # Obr. 4