CMU 15-112 Summer 2020: Fundamentals of Programming and Computer Science
Homework 13 (Due Tue 16-Jun, at 5:00pm)

• This assignment is SOLO. This means you may not look at other student's code or let other students look at your code for these problems. See the syllabus for details.


• To start:
  1. Create a folder named 'hw13'
  2. Create and edit hw13.py using VSCode. Note that we are not providing a starter file for this assignment. You should copy and paste these test cases into your own file, and create classes with methods and attributes such that the tests all pass.
  3. When you are ready, submit hw13.go to Autolab. For this hw, you may submit up to 10 times, but only your last submission counts.
• Do not hardcode the test cases in your solutions.

1. Asteroid Class and Subclasses [50pts]
   Write the Asteroid, ShrinkingAsteroid, and SplittingAsteroid classes so that they pass testAsteroidClasses, and uses the OOP constructs we learned as appropriate.
   On hw14, you will use these classes in your animation!
   Hint: You can use self.__class__.__name__ to get the name of an instance's class.
   def getLocalMethods(clss): import types # This is a helper function for the test function below. # It returns a sorted list of the names of the methods # defined in a class. It's okay if you don't fully understand it! result = [ ] for var in clss.__dict__: val = clss.__dict__[var] if (isinstance(val, types.FunctionType)): result.append(var) return sorted(result) def testAsteroidClasses(): print("Testing Asteroids classes...", end="") # A basic Asteroid takes in cx, cy, radius, speed, and optional direction. # It's default direction (dx, dy) is (0, 1), or moving down asteroid1 = Asteroid(25, 50, 20, 5) assert(type(asteroid1) == Asteroid) assert(isinstance(asteroid1, Asteroid)) asteroid1.setDirection((-1, 0)) assert(asteroid1.getDirection() == (-1,0)) assert(str(asteroid1) == "Asteroid at (25, 50) with radius=20 and direction (-1, 0)") assert(str([asteroid1]) == "[Asteroid at (25, 50) with radius=20 and direction (-1, 0)]") # isCollidingWithWall takes in the canvasWidth and canvasHeight # Asteroids collide with walls if any part of them is touching any side # of the canvas assert(asteroid1.isCollidingWithWall(400, 400) == False) asteroid1.move() assert(str(asteroid1) == "Asteroid at (20, 50) with radius=20 and direction (-1, 0)") assert(asteroid1.getPositionAndRadius() == (20, 50, 20)) assert(asteroid1.isCollidingWithWall(400, 400) == True) # A normal asteroid is stunned when it is hit by a bullet, and it freezes asteroid1.reactToBulletHit() assert(asteroid1.getDirection() == (0, 0)) assert(getLocalMethods(Asteroid) == ['__init__', '__repr__', 'getDirection', 'getPositionAndRadius', 'isCollidingWithWall', 'move', 'reactToBulletHit', 'setDirection']) # A Shrinking Asteroid takes in cx, cy, radius, speed, # an optional direction (that is (0, 1) by default), # and an optional shrinkAmount set to 5 pixels by default. # ShrinkAmount is how much the radius of the asteroid decreases when it is # hit by a bullet. A Shrinking Asteroid can also bounce off the walls. asteroid2 = ShrinkingAsteroid(200, 200, 50, 20) assert(type(asteroid2) == ShrinkingAsteroid) assert(isinstance(asteroid2, ShrinkingAsteroid)) assert(isinstance(asteroid2, Asteroid)) asteroid2.reactToBulletHit() assert(asteroid2.getPositionAndRadius() == (200, 200, 45)) assert(str(asteroid2) == "ShrinkingAsteroid at (200, 200) with radius=45 and direction (0, 1)") asteroid2.setDirection((1, -1)) asteroid2.bounce() assert(asteroid2.getDirection() == (-1, 1)) asteroid3 = ShrinkingAsteroid(100, 100, 40, 10, direction=(0, -1), shrinkAmount=20) # The asteroid's radius will decrease by the shrinkAmount asteroid3.reactToBulletHit() assert(asteroid3.getPositionAndRadius() == (100, 100, 20)) assert(getLocalMethods(ShrinkingAsteroid) == ['__init__','bounce', 'reactToBulletHit']) # A Splitting Asteroid takes in cx, cy, radius, speed, and an optional # direction (set to (0, 1) by default). It splits into two smaller # Splitting Asteroids when hit by a bullet. # The each smaller Splitting Asteroid has radius that is half of # the original Splitting Asteroid's and has the original speed and direction asteroid4 = SplittingAsteroid(300, 300, 20, 15) assert(type(asteroid4) == SplittingAsteroid) assert(isinstance(asteroid4, SplittingAsteroid)) assert(isinstance(asteroid4, Asteroid)) assert(not isinstance(asteroid4, ShrinkingAsteroid)) # reactToBulletHit returns 2 new instances of the SplittingAsteroid class asteroid5, asteroid6 = asteroid4.reactToBulletHit() # The new Splitting Asteroid centers are at the top-left and bottom-right # corners of the bounding box surrounding the original asteroid # See the test cases below for an example: assert(asteroid5.getPositionAndRadius() == (280, 280, 10)) assert(asteroid6.getPositionAndRadius() == (320, 320, 10)) assert(str(asteroid6) == "SplittingAsteroid at (320, 320) with radius=10 and direction (0, 1)") assert(getLocalMethods(SplittingAsteroid) == ['reactToBulletHit']) print("Done!")