from OpenGL.GL import *
from OpenGL.GLUT import *
import math


WIDTH, HEIGHT = 2,2

def draw_points(x, y):
    glPointSize(2.0)
    glBegin(GL_POINTS)
    glVertex2f(x, y)
    glEnd()

def midpointCircle(x0, y0, r):
    d = 1 - r / WIDTH
    x = 0
    y = r
    while x < y:
        draw_points((x + x0) / WIDTH, (y + y0) / HEIGHT)
        draw_points((y + x0) / WIDTH, (x + y0) / HEIGHT)
        draw_points((-x + x0) / WIDTH, (-y + y0) / HEIGHT)
        draw_points((-y + x0) / WIDTH, (-x + y0) / HEIGHT)
        draw_points((-x + x0) / WIDTH, (y + y0) / HEIGHT)
        draw_points((y + x0) / WIDTH, (-x + y0) / HEIGHT)
        draw_points((x + x0) / WIDTH, (-y + y0) / HEIGHT)
        draw_points((-y + x0) / WIDTH, (x + y0) / HEIGHT)

        if d < 0:
            d += 2 * x + 3
        else:
            d += 2 * x - 2 * y + 5
            y -= 1
        x += 1



def draw_circles(x0, y0, r, num):
    midpointCircle(x0, y0, r)
    num2 = math.pi * 2 / num
    for a in range(1,num):
        midpointCircle(x0 + (r / 2) * math.cos(a * num2), y0 + (r / 2) * math.sin(a * num2), r / 2)

def iterate():
    glViewport(0, 0, 500, 500)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glOrtho(0.0, 500, 0.0, 500, 0.0, 1.0)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

def showScreen():
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glLoadIdentity()
    iterate()
    glColor3f(1.0, 1.0, 1.0)


    draw_circles(X_CO, Y_CO, R, num)


    glutSwapBuffers()


num = 9
X_CO = 500
Y_CO = 500
R = 400


glutInit()
glutInitDisplayMode(GLUT_RGBA)
glutInitWindowSize(500, 500) #window size
glutInitWindowPosition(0, 0)
wind = glutCreateWindow(b"OpenGL Coding Practice") #window name


glutDisplayFunc(showScreen)


glutMainLoop()