# t_Gravity_Bounce_X_and_Y.py

# t_Gravity_Bounce_X_and_Y.py

import turtle

win = turtle.Screen()
win.title('Gravity Bounce X and Y')
win.setup(1000,600)
win.tracer(0) # skips animation until win.update()

ball = turtle.Turtle()
ball.shape('circle')
ball.color('red')
ball.up() # lift pen up
ball.goto(-480,250)
ball.dy = 0
ball.dx = 0.5 # will move to the right 1 pixel/loop
ball.down() # put pen down for drawing

ground = turtle.Turtle()
ground.shape('square')
ground.shapesize(0.5, 80) # turtle is looking to right, 0.5x and 40y stretch
ground.up()
ground.goto(0, -275)
ground.color('green')

gravity = 0.09 # may need adjustment in windows
remaining_energy = 0.9 # increase for more bounce, decrease for less
roll_energy = 0.0008

win.update()

while 1:

    ball.dy -= gravity
    ball.goto(ball.xcor()+ball.dx, ball.ycor()+ball.dy)

    if ball.ycor() <= -259 and ball.dy<0:
        ball.dy *= -1
        ball.dy *= remaining_energy

        if ball.dy < 0.5:
            ball.dy = 0
            gravity  = 0
            remaining_energy = 0
    if not ball.dy:
        ball.dx = max(0, ball.dx-roll_energy)

    if not ball.dx:
        break