from uturtle import (
    umonsTurtle, wait,
    moveForward, moveBackward,
    turnLeft, turnRight,
    dropPen, usePen)


def arbre(t, x, a, n):
    """draw a tree

    :t: turtle
    :x: taille du tronc de base
    :a: angle des branches
    :n: profondeur de l'arbre
    """
    moveForward(t, x)
    arbre_rec(t, x, a, n)


def arbre_rec(t, x, a, n):
    if n == 0:
        return
    turnLeft(t, a/2)
    moveForward(t, x)
    arbre_rec(t, x*5/6, a*5/6, n-1)
    moveBackward(t, x)

    turnRight(t, a)
    moveForward(t, x)
    arbre_rec(t, x*5/6, a*5/6, n-1)
    moveBackward(t, x)

    turnLeft(t, a/2)


if __name__ == "__main__":
    turtle = umonsTurtle()
    turnLeft(turtle)
    arbre(turtle, 50, 45, 4)
    wait()