CMSC 110 (Introduction to Computing)

Fall 2012 - Section 2

Assignment #6

Due by 4:00 pm on Tuesday, November 27, 2012

Task: Design an underwater creature that will live in a virtual aquarium.

Your creature should be implemented as a child class of the Creature class (defined below). Name your child class after your Emailusername. For example, my creature child class will be named Mfrusso. Your child class's constructor should take a single numeric size argument. The size of your creature should be close to that of a circle with diameter equal to the size argument. Make sure your child class includes one method called draw() and one called move() so that I can incorporate your creature into a sketch with other creatures. The move() method causes the creature to swim about using some model of motion. The draw() method draws your creature at its current location. Finally, your Creature child class should implement some special "move behavior." Some creatures will swim like a fish, or a submarine, some will wiggle, some might just stay in one place and rotate, flash, bubble, etc.

Steps:

1. Cut and paste the following code into the Calico editor.
2. Add your own Creature child class to the program where indicated in red. Your child class constructor should take a single size argument.
3. Override the move() and draw() methods of the Creature base class to give your child class its own unique behavior.
4. Add additional instance variables to your child class, as needed.
5. Add at least one "move behavior" to your child class beyond the required change in location over time.
6. Create at least three instances of your class and test it by adding to the creatures list.

from Processing import *

# Base class for all creatures
class Creature:

    # Construct the class
    def __init__(self, size):
        self.size = size
        self.x = random( width() )
        self.y = random( height() )

    # Move the creature
    def move(self):
        pass

    # Draw the creature
    def draw(self):
        ellipse(self.x, self.y, self.size, self.size)

    # Return the location of the creature as a dictionary
    def location(self):
        return {'x':self.x, 'y':self.y}


# Your custom Creature child class goes here.
# Use your email username as the name of the custom child class.
# Override Creature base class methods as necessary to create custom behavior.


# List of all creatures
creatures = []

# Create at least three creatures and add to creatures list.
# Create instances of your subclass here, not the Creature base class.
creatures.append( Creature(50) )
creatures.append( Creature(75) )
creatures.append( Creature(60) )

# Create sketch window
window(800, 600)

# Draw all creatures
def draw(o, e):
    # Draw the tank background
    background(128, 128, 255)

    # Draw and animate each of the creature objects
    for c in creatures:
        c.move()
        c.draw()

# Draw all
frameRate(30)
onLoop += draw
loop()

Extra Credit:

For up to 20 points extra credit, have your creature react to nearby creatures in the aquarium. Use the global creatures list to access all other creatures in the aquarium. Call the base class location() method to get the x-y location of each creature. If another creature is sufficiently close to your creature, modify the appearance of your creature in some way. Some might turn red or puff out, others might swim away.

If you choose to complete the extra credit, be certain to clearly indicate that fact in your assignment and include a description of your creature's behavior.

Requirements:

• Your custom child class of Creature
• Your class's constructor with size argument
• Overridden move() and draw() methods that move and draw your child class
• At least one "move behavior" appropriate to your creature, beyond the required change in location over time
• A program that creates three or more instances of your creature swimming in your own creature tank
• For extra credit, include an updated implementation of move() or draw() that reacts in some way when another creature is close

Note that the final showcase will include one instance of each creature defined by you and your classmates swimming together in a single aquarium sketch.