# drawing.py
# ----------
# Nelson Mason
# updated 9-21-2025
# Due by 9-29-2025
# (This is an animation of a sunrise.)

from turtle import *
from superturtle.animation import animate

# define 3 objects
# sky, ground, sun

# In the actual animation, the sun will start off entirely below the horizon,
# (where the sky meets the ground), hidden by the ground, and will slowly rise (move up the screen),
# with the sun, sky, and ground changing color. The disk of the sun will
# be apparent only in the sky, as it rises. I will be using color shading techniques in the animation.

def sky():
    begin_fill() # draw the sky
    fillcolor("dark blue")   
    for x in range(2):
        forward(400)
        left(90)        
        forward(300)
        left(90)
    end_fill()

def ground():
    begin_fill() # draw the ground
    fillcolor("black")
    for x in range(2):
        forward(400)
        right(90)        
        forward(150)
        right(90)
    end_fill()

def sun():
    begin_fill() # draw the sun
    fillcolor("red")
    circle(-62,360) 
    end_fill()

def sun_position(a): # this must be called to get the sun to move up (rise)
    penup()
    left(90)
    forward(a)
    right(90)
    pendown()

for frame in animate(frames=1000):
    penup() # reposition the turtle before drawing the sky
    right(180)
    forward(200)
    left(90)
    forward(50)
    left(90)
    pendown()
    sky()
    penup() # reposition the turtle before drawing the sun
    forward(200) # starting the drawing of the sun right on the horizon
    # makes it easier to calculate everything else
    pendown()
    a = frame.interval=200 # the frames-to-interval ratio controls the animation speed
    a = frame.interpolate(0, 275) # low and high positions of the sun as it rises
    sun_position(a)
    sun() # draws the sun   
    penup() # reposition the turtle before drawing the ground
    right(180)
    forward(200)
    left(90)
    forward(+a) # increment to get to the correct starting point for 
    # the next iteration(re-drawing) of the sun rising
    left(90)
    pendown()
    ground() # I want the ground to hide the sun (overlay), but not the sky (obviously)

input()