CS152
Project 8: Pinball Wizard
The focus of this project is to continue reworking our classes into an inheritance hierarchy and adding new shapes to our visualization. We will also use a dictionary to make working with collisions more streamlined.
Project Tasks
T1. Create a Block class
The first task is to create a Block child class using inheritance. The parent class is Thing).
a. Define the Block init method
The init method should have the following signature. You are welcome to add additional optional arguments.
def init (self, win,x0=0,y0=0,width=2,height=1, color=None):
As with the Ball class, the first action in the init method is to call the parent
Thing. init method. Specify the type as the string "block". Any parameters you don't pass to the Thing. init method should then be assigned to their proper field.
Assign the dx parameter to the field self.dx and the dy parameter to the field dy. You can use self.width and self.height if you wish (or any other names of your choice).
Finally, call self.reshape() and self.color() to set up the vis list and set the color.
b. Create the reshape method
def reshape (self):
The reshape method should undraw the graphics objects if they are drawn. Then it should define the self.vis list of graphics objects using the current fields. Then it should draw the graphics objects if they are drawn. Note that if you use the undraw and draw methods, they affect the value of self.drawn. Therefore, it's best to make a local copy of self.drawn and use that to test if the object needs to be undrawn/drawn.
When creating the visualization for the Block, put the anchor point in the center of the block. One corner should be at (x0-width/2, y0-height/2) and the other corner should be at (x0+width/2, y0+height/2).
c. Write getWidth and getHeight
These two functions should return the width or height of the block.
d. Write setWidth and setHeight
These two functions should update the value of the width (dx) field or the height (dy) field and then call the reshape method.
T2. Make another shape class of your choice
Choose a shape. It can be a polygon (e.g. a triangle or a pentagon) or it could be a multi-object shape like a snowman. The new shape class should inherit from Thing. The init method should make sure all the necessary information is provided and finish by calling reshape and setColor.
The reshape method should define the graphics objects that define the simulated object. It's ok if this class is just a single graphics object. When you define the object's visualization, define it so that the object's position corresponds to the center of the object, just like it did for the Ball and Block classes.
If the shape is best modeled as a block (for the purpose of collisions) then it will need getHeight, getWidth, setHeight, and setWidth methods. If the shape is best modeled as a circle, then it will need getRadius and setRadius methods.
If the class has a complicated color scheme, you may need to write a setColor for the child class. If the class is a multi-shape object, you may need to write a set Position function for the child class.
T3. Write a unified collision function
The next task is to modify the collision.py file to make it simpler to call the right collision function no matter what types of objects are involved. (Note, the collision functions all work with a ball and something else. We don't yet have block-block collisions, for example.)
The idea is to use a dictionary with the two types involved in the collision as the key, making use of the type field in the Thing class. For example, if we have two objects, item1 and item2, we can create a key by writing:
key = (item1.getType (), item2.getType ())
The key is a tuple that has two strings in it. Then, we can generate a dictionary entry that contains all the possible keys and stores the proper function to call in each case. For example, the following creates an entry in the dictionary collision_router with the key ('ball', 'ball') and sets its value to the function reference collision_ball_ball.
collision_router [ ('ball', 'ball') ] = collision_ball_ball
The above line creates a new entry in the collision_router dictionary with the key ('ball', 'ball') and its value is a function reference to the collision_ball_ball function (note there are no parentheses after collision_ball_ball). This entry in the dictionary can be used to call the collision_ball_ball function using the following syntax.
collision_router [ ( 'ball ', 'ball ') ] (thing1, thing2)
At the bottom of the collision.py file, at the top level (meaning totally unindented), create an empty dictionary called collision_router. Then add an entry to the dictionary (as above) for each possible collision of a ball and another type: ball, block, and the additional shape you created (which should be treated as either a ball or a block.
Finally, create a function called collision (ball, thing,timestep)that takes in two Thing objects plus a time step and uses the collision_router dictionary to call the right function. Assume that the ball is always the first parameter and the other object (ball, block, or other) is the second parameter.
T4. Create an animated scene with obstacles
Required Element 1: pinball.py
Create a new file name pinball.py In this file you will create a scene that is like a pinball table. If you don’t know what that is follow this link: Pinball Machine
Your pinball machine should have outside boundaries made of rows of blocks and some obstacles inside the box that are all stationary. It does not need to be completely enclosed.
The default behavior. should be for the program to launch a single ball into the scene and have it bounce around.
To create the scene, the following is a suggested structure for your code to get started.
def buildObstacles (win):
# Create all of the obstacles in the scene and put them
in a list
# Each obstacle should be a Thing (e.g. Ball, Block,
other)
# You might want to give one or more the obstacles an
elasticity > 1
# Return the list of Things
def main ():
# create a GraphWin
# call buildObstacles, storing the return list in a
variable (e.g. shapes)
# loop over the shapes list and have each Thing call
its draw method
# assign to dt the value 0.02
# assign to frame the value 0
# create a ball, give it an initial velocity and
acceleration, and draw it
# start an infinite loop
# if frame. modulo 10 is equal to 0
# call win.update ()
# using checKey, if the user typed a 'q' then break
# if the ball is out of bounds, re-launch it
# assign to collided the value False
# for each item in the shapes list
# if the result of calling the collision
function with the ball and the item is True
# set collided to True
# if collided is equal to False
# call the update method of the ball with dt as
the time step
# increment frame.
# close the window
if name == " main ":
main ()
Doing visual updates only every 10th frame. will make the animation smoother. What that does is run the virtual simulation for 10 time steps and then redraw the objects in their new positions.
You can adjust both the time step and how often the visualization is redrawn to change the visual behavior. of the simulation.
Required Element 2: Create a video of your pinball machine in action and upload a copy along with your Google Doc report.
T5. Create one more shape class
Create a new class that makes a new shape with at least two graphics objects. Consider this object to be of type ball for the purpose of collisions. Replace the ball in your obstacle scene with the new shape (so the new shape should be bouncing around).
Required Element 3: Create a video which includes your compound shape and upload a copy along with your Google Doc report.
Follow-up Questions
1. What is inheritance?
2. What does it mean for a child class to override a method?
3. What is a class variable or class global variable?
4. What is a field of an object?
Extensions
Extensions are your opportunity to customize your project, learn something else of interest to you, and improve your grade. The following are some suggested extensions, but you are free to choose your own. Be sure to describe any extensions you complete in your report.
● Make your pinball game interactive giving the user some control over the visualization. Perhaps they could launch multiple balls, change the attributes of the balls or otherwise modify the scene in some way.
● Create more elaborate spaces and develop interesting additional simulation videos.
● Create more shape classes and show that they collide and simulate appropriately.
● Add the capability to hit the ball with a block.
● Create a separate scene game like putt-putt golf and let the user shoot the golf ball.
Write your project report
Reports are not included in the compressed file! Please don’t make the graders hunt for your report.
You can write your report in any word processor you like and submit a PDF document in the Google Classroom assignment folder. Or use a Google Document format.
Review the Writeup Guidelines document in the Labs and Projects folder.
Your intended audience for your report is your peers who are not taking CS classes.
From week to week, you can assume your audience has read your prior reports. Your goal should be to explain to peers what you accomplished in the project and to give them a sense of how you did it. The following is a list and description of the mandatory sections you must include in your report. Do not include the descriptions in your report, but use them as a guide in writing your report.
● Abstract
A summary of the project, in your own words. This should be no more than a few sentences. Give the reader context and identify the key purpose of the assignment. An abstract should define the project's key lecture concepts in your own words for a general, non-CS audience. It should also describe the program's context and output, highlighting a couple of important algorithmic and/or scientific details. Writing an effective abstract is an important skill. Consider the following questions while writing it.
○ Does it describe the CS concepts of the project (e.g. writing well-organized and efficient code)?
○ Does it describe the specific project application (e.g. generating data)?
○ Does it describe your solution and how it was developed (e.g. what code did you write)?
○ Does it describe the results or outputs (e.g. did your code work as expected and what did the results tell you)?
○ Is it concise?
○ Are all of the terms well-defined?
○ Does it read logically and in the proper order?
● Methods
The method section should describe in clear sentences (without pasting any code) at least one example of your own computational thinking that helped you complete your project. This could involve illustrating how a key lecture concept was applied to creating an image, how you solved a challenging problem, or explaining an algorithmic feature that is essential to your program as well as why it is so essential. The explanation should be suitable for a general audience who does not know Python.
● Results
Present your results in a clear manner using human-friendly images or graphs labeled with captions and interpreted for a general audience such as your peers not in the course. Explain, for a general, non-CS audience, what your output means and whether it makes sense.
● Reflection and Follow-up questions
Draw connections between lecture concepts utilized in this project and real-world problems that interest you. How else could these concepts apply to our everyday lives? What are some specific things you had to learn or discover in order to complete the project? Look for a set of short answer questions in this section of the report template.
● Extensions (Required even if you did not do any)
A description of any extensions you undertook, including text output or images demonstrating those extensions. If you added any modules, functions, or other design components, note their structure and the algorithms you used.
● References/Acknowledgements (Required even if there are none)
Identify your collaborators, including TAs and professors. Include in that list anyone whose code you may have seen, such as those of friends who have taken the course in a previous semester. Cite any other sources, imported libraries, or tutorials you used to complete the project.
Submitting your Project Report and Code
Turn in your code by zipping the file and uploading it to Google Classroom. When submitting, double check the following.
1. Is your name at the top of each Python file?
2. Does every function have a docstring (‘’’ ‘’’) specifying what it does?
3. All your code is in your Project 08 folder?
4. Have you checked to make sure you have included all required elements and outputs in your project report?
5. If you have done an Extension, have you included this information in your report under the Extension heading? Even if you have not done any extensions, include a section in your report where you state this.
6. Have you acknowledged any help you may have received from classmates, your instructor, the TAs, or outside sources (internet, books, videos, etc.)? If you received no help at all, have you indicated that under the Sources heading of the report?