# t_random_2D_mountain.py

# t_random_2D_mountain.py

import turtle
import math
import random

screen = turtle.Screen()
screen.setup(1200,600)
screen.title("Random 2D Mountain")

turtle.hideturtle()
turtle.speed(0)
turtle.pensize(2)
turtle.color('dark green')
MAX_SLOPE = 45
MIN_SLOPE = -45
MIN_HEIGHT = -200
def dist_squared(P1,P2):
    return (P1[0]-P2[0])**2 + (P1[1]-P2[1])**2

def mountain(P1,P2):
    turtle.up()
    turtle.goto(P1)
    turtle.down()
    def mtnDraw(P1,P2):
        if dist_squared(P1,P2) < 9:
            turtle.goto(P2)
            return
        x1,y1 = P1
        x2,y2 = P2
        x3 = random.uniform(x1,x2)
        y3_max = min((x3-x1)*math.tan(math.radians(MAX_SLOPE)) + y1, (x2-x3)*math.tan(-math.radians(MIN_SLOPE)) + y2)
        y3_min = max((x3-x1)*math.tan(math.radians(MIN_SLOPE)) + y1, (x2-x3)*math.tan(-math.radians(MAX_SLOPE)) + y2)
        y3_min = max(y3_min, MIN_HEIGHT)
        y3 = random.uniform(y3_min,y3_max)
        P3 = (x3, y3)
        mtnDraw(P1,P3)
        mtnDraw(P3,P2)
    mtnDraw(P1,P2)
    return

mountain((-500,MIN_HEIGHT),(500,MIN_HEIGHT))