import pygame
import math
from time import sleep

width = 640
height = 480


screen = pygame.display.set_mode((width,height))

def draw_pixel(x,y,r=255,g=255,b=255):
        screen.set_at((int(x),int(y)), (r,g,b))



def draw_line(x1,y1,x2,y2):
    if x1 == x2:
        if y2 < y1:
            for y in range(y1,y2-1, -1):
                draw_pixel(x1,y)
            return
        else:
            for y in range(y1,y2+1):
                draw_pixel(x1,y)
            return
    if y1 == y2:
        if x2 < x1:
            for x in range(x1,x2-1,-1):
                draw_pixel(x,y1)
            return
        else:
            for x in range(x1,x2+1):
                draw_pixel(x,y1)
            return

    rise = float(y2 - y1)
    run = float(x2 - x1)


    riser = rise/run
    runr = 1
    slope = riser/runr
    if rise < run:
        if x1 < x2:
            for x in range(x1, x2-1,-1):
                y = round(slope*x+y1)
                draw_pixel(x,y)
        else:
            for x in range(x1, x2+1):
                y  = round(slope*x+y1)
                draw_pixel(x,y)
    else:
        if y2 < y1:
            for y in range(y1, y2-1, -1):
                x = round((y-y1)/slope+x1)
                draw_pixel(x,y)
        else:
            for y in range(y1, y2+1):
                x = round((y-y1)/slope+x1)
                draw_pixel(x,y)



def draw_circle(radius, x=0, y=0):
        assert radius >= 1, 'first argument radius must be 1 or greater'
        points_list = []
        mirrored_list = []
        for xc in range(1,radius+1):
                high = radius
                low = 0
                guess = (high + low) / 2.0
                ctr = 1
                while abs(radius - math.sqrt((xc**2 + guess**2))) > 0.000000001 and ctr <100:
                        if (xc**2 + guess**2) < radius**2:
                                low = guess
                        else:
                                high = guess
                        ctr +=1
                        guess = (high + low) / 2.0
                assert ctr <= 100, 'iteration count exceeded in draw_point'
                yc = round(guess)
                points_list.append((xc,yc))
                points_list.append((yc,xc))

        points_list = list(set(points_list))
        for coord in points_list:
                draw_pixel(coord[0]+x,coord[1]+y)
                mirrored_list.append(((coord[0]*-1),coord[1]))
                mirrored_list.append(((coord[0]*-1),(coord[1])*-1))
                mirrored_list.append((coord[0],(coord[1]*-1)))
        for coord in mirrored_list:
                draw_pixel(coord[0]+x,coord[1]+y)

draw_circle(100, 200, 200)
pygame.display.flip()
sleep(1)
draw_line(30,30, 40, 250)
pygame.display.flip()
sleep(1)
draw_line(30,30, 30,200)
pygame.display.flip()
sleep(1)
draw_line(30,30, 200,30)
pygame.display.flip()
sleep(1)
draw_line(100, 100, 50, 300)
pygame.display.flip()
sleep(1)
draw_line(100, 100, 100, 1)
pygame.display.flip()
sleep(1)
draw_line(100, 100, 50, 100)
pygame.display.flip()
sleep(1)
#this one below this comment doesn't work
draw_line(100, 100, 50, 10)
pygame.display.flip()
sleep(1)
draw_line(100, 100, 10, 50)
pygame.display.flip()
sleep(1)
sleep(10)