# RecursiveTree.py
#
# Description: Draws a tree recursively.
#
# Author: AL and AL
# Date: Oct. 20 2023

# Import the turtle library
import turtle

# Define a recurisve function that draws a tree
def drawTree(aTurtle, aLevel, aBranchLength):
    '''Draws a tree recursively where
       "aTurtle" is the turtle drawing the tree,
       "aLevel" is the number of levels of branches and
       "aBranchLength" the length of branch to draw.
    '''

    # Base Case:
    # If we are at the leaf level (level == 0), draw a green leaf!
    if aLevel == 0:
        aTurtle.color("green")
        aTurtle.stamp()
        aTurtle.color("brown")
        
    else:
        # Recursive Case:
        # Draw a branch
        aTurtle.forward(aBranchLength)

        # Turn left and draw a smaller tree
        aTurtle.left(40)
        drawTree(aTurtle, aLevel - 1, aBranchLength/1.5)

        # Turn right and draw a smaller tree
        aTurtle.right(80)  # 40 + 40
        drawTree(aTurtle, aLevel - 1, aBranchLength/1.5)
        
        # Go back
        aTurtle.left(40)
        aTurtle.back(aBranchLength)

    return


# ***Main part of my program

# Creates a graphics window "canvas"
canvas = turtle.Screen()

# Create a turtle named "tt"
tt = turtle.Turtle()

# Set up our turtle "tt"
tt.color("brown")
tt.width(3)
tt.shape("triangle")

# Move our turtle "tt"
tt.speed(6)
tt.penup()
tt.goto(0, -180)
tt.left(90)
tt.pendown()
theBranchLength = 100
tt.forward(theBranchLength)

# Call our recursive function
theLevel = 5
drawTree(tt, theLevel, theBranchLength)
tt.back(theBranchLength)

# Click on the canvas to exit
canvas.exitonclick()