#####################################################################
#
# graphics0.py
#
# Developed originally in Pascal by Jeff Ondich on 1/25/95
# Ported to C++, Java, and Python
# Last modified 1/19/07
#
# This program opens a graphics window, fills it with a black
# background, and draws a red circle in the center.
#
# Try doing these things:
#
# 0. Run the program as it is.  You'll need a copy of John
#    Zelle's graphics.py in your working directory.
# 1. Read the whole program to find out how it works.
# 2. What happens if you remove the "s = raw_input('')" at the
#    end of the main program?
# 3. Modify the code to draw a tall and skinny graphics
#    window.  Where does the circle get drawn when you
#    run your new version of the program?  Why?
# 4. Change the background color.  Can you make it white?
# 5. Make the circle green.
# 
#####################################################################

from graphics import *

# Define some values that we will use later.  It is handy
# to define these quantities together here at the top, because
# that makes it easy to modify them later.
windowHeight = 400;
windowWidth = 600;
windowTitle = 'Circle Demo'
radius = 100;

# Define some colors.  To do color graphics, you specify
# colors via red, green, and blue values.  A red value of
# 0 means no red at all, while a red value of 255 means
# as much red as possible.  For example, color_rgb(255, 0, 255)
# is a bright purple, while color_rgb(150, 0, 150) is a
# darker purple.
backgroundColor = color_rgb(0, 0, 0)
circleColor = color_rgb(200, 80, 80)

# Open a window with the specified title, width, and height.
window = GraphWin(windowTitle, windowWidth, windowHeight)
window.setBackground(backgroundColor)

# Create and draw a circle.
center = Point(windowWidth / 2, windowHeight / 2)
circle = Circle(center, radius)
circle.setFill(circleColor)
circle.draw(window)

# Wait for user input.
response = raw_input('Hit Enter to quit')