import pygame
import time
import sys
import random

WIDTH, HEIGHT = 600, 600
WHITE = (255, 255, 255)
BLUE = (0,100,200)
PINK = (255, 0, 120)

#### SETTINGS ###

LINE_WIDTH = 3
TREE_ROOT = [WIDTH/2, HEIGHT]
ROOT_LEN = 100
TREE_LEN = 10

#### SETTINGS ###

pygame.init()
canvas = pygame.display.set_mode((WIDTH,HEIGHT))
background  = pygame.Surface((WIDTH,HEIGHT))
font = pygame.font.SysFont("Calibri", 30)
pygame.display.set_caption('Pretty tree')
clock = pygame.time.Clock()

def quitGame():
    pygame.quit()
    sys.exit(0)

class Branch():
    def __init__(self, start, end):
        self.start = start
        self.end = end

    def show(self):
        pygame.draw.line(canvas, PINK, self.start, self.end, LINE_WIDTH)

    def leftBranch(self):
        newLeftEnd=[]
        newLeftEnd.append(self.end[0] + 50)
        newLeftEnd.append(self.end[1] - 50)
        return newLeftEnd

    def rightBranch(self):
        newRightEnd=[]
        newRightEnd.append(self.end[0] - 50)
        newRightEnd.append(self.end[1] - 50)
        return newRightEnd

start = TREE_ROOT
end = [WIDTH/2, HEIGHT - ROOT_LEN]

tree = []
root = Branch(start,end)
tree.append(root)

while True:
    for event in pygame.event.get():

        if event.type == pygame.QUIT:
            quitGame()
        if event.type == pygame.MOUSEBUTTONUP:
            for i in range(len(tree)):
                tree.append(Branch(end, tree[i].leftBranch()))
                tree.append(Branch(end, tree[i].rightBranch()))
                tree[i].show()

    pygame.display.flip()
    clock.tick(60)