#!/usr/bin/python
# -*- coding: utf-8 -*-
from graph import *
from math import sin, cos, pi
# via https://gist.github.com/blzzua/063b1d8d05663c7c00fdf6fabc3a87b5
def ellipse( x1, y1, x2, y2, angle_degrees=0, vertex_count = 36):
    """
    Рисует эллипс, вписанный в прямоугольник x1,y1 x x2,y2
    """
    angle_rad = angle_degrees * pi / 180
    print(f'angle_degrees={angle_degrees}, angle_rad={angle_rad}')
    (x1, x2) = (min(x1, x2), max(x1, x2))
    (y1, y2) = (min(y1, y2), max(y1, y2))
    a = (x2 - x1) / 2
    b = (y2 - y1) / 2
    ## https://ru.wikipedia.org/wiki/Эллипс#Уравнения_в_параметрической_форме
    TMP_VERTEX = [ (a * cos( i * 2 * pi / vertex_count), \
                    b * sin( i * 2 * pi / vertex_count)) \
                    for i in range(vertex_count) ]
    VERTEX = []
    for x,y in TMP_VERTEX:
        tx =      x * cos(angle_degrees) + y * sin(angle_degrees) + ( x1 + x2 ) / 2
        ty = -1 * x * sin(angle_degrees) + y * cos(angle_degrees) + ( y1 + y2 ) / 2
        VERTEX.append((tx,ty))

    mypol = polygon(VERTEX)
    return mypol


if __name__ == '__main__':
    "демонстрация. рисует разноцветные эллипсы"
    from random import randrange
    max_x = 500
    max_y = 600
    min_x = 10
    min_y = 10
    for i in range(20):
        brushColor(randColor())
        penColor(randColor())
        (x1, y1) = (randrange(start=min_x, stop=max_x),
                    randrange(start=min_y, stop=max_y))
        (x2, y2) = (randrange(start=min_x, stop=max_x),
                    randrange(start=min_y, stop=max_y))
        ellipse(x1, y1, x2, y2, angle_degrees=randrange(180), vertex_count=randrange(8,30) )
    run()