TU856/TU858 Object Oriented Programming 2024

Resources

git reference

Contact the lecturer

Email: bryan.duggan@tudublin.ie
Web: http://bryanduggan.org

Assignment

Assignment
Wed 24th April IN PERSON DEMOS

Week 8 - YASC - Part 1

Recording

Tutorial

public int countYZ(String str) {
  int count = 0;
  
  for(int i = 0 ; i < str.length() ; i ++)
  {
    char c = Character.toLowerCase(str.charAt(i));
    boolean isLast = (i == str.length() - 1);
    
    if ((c == 'y' || c == 'z') && (isLast || !Character.isLetter(str.charAt(i+1))))
    {
      count ++;
    }
  }
  return count;
}

Lab

Your task today is to meet your team

Decide on a song. Select a few genres and decide on something that will work for all the team. Crazy experimental music, world music and live music performance and also options
Brainstorm some ideas. You can look at the playlists of the previous years as inspiration.
Meet me and tell me what u are planning
Fork the starter code git repo, set up the remotes
Add each team member as collaborator
Each team member clone the repo, get it working
Each team member make one commit
Submit your team details

Week 7 - Audio Part 2

Week 6 - Audio Part 1

Recording

If you would like to be part of a team and dont have one, fill out this form and I will assign you a team.

Lab

Learning Outcomes

Practice for loops
Learn about color, sound and maths
Demonstrate an understanding of how digital audio works
Practice computational thinking and problem solving
Have fun making beautiful things

Accept this assignment on github classroom. Make some commits and attempt this task. It will prepare you with knowledge and skills to do the assignment.

Sound.java this is the code we wrote on Monday.

Put your work today into the file Audio1.java which has some starter code for todays task.

Checkout the keyPressed function. This starts and restarts the audio file when you press space. Also it sets the value of the mode variable to be the numbers 0-5 when you press the appropriate key on the keyboard. If your computer wont play the audio file for some reason,you can uncomment the code to read audio from the microphone instead or use a .wav file instead.

You should make an array the same size as the buffer and lerp the samples to each element in the buffer (similar to how we did the average). This will make all your visualisations smoother

Ok now check out this video of 5 visuals you can make today. Pressing the keys 0-4 on the keyboard should change the visual in your sketch.

The wavy lines visual - To make this, flip the order of the x2, y2 parameters on the line
The waveform
The waveform drawn down the 4 sides of the screen
The circle - Use the lerped amplitude to control the size of the circle
The square - Again use the lerped amplitude to control the size of the square. You can also use rectMode(CENTER) to make the x and y parameters of the rect function determine the center of the rect rather than the coordinates of the top left corner
There is no visual associated with 5 in the video, so come up with your own!

The assignment repo

Week 5 - The Game of Life

Lab

Learning Outcomes

How to implement the logic of an algorithm
How cellular automata works
Writing java code
Understanding how to visualise the contents of a 2D array
Iterate over a 2D array

Accept this assignment. Clone the repo you are given, do the work below, commit and push your changes before Friday @ midnight.

Implement the missing parts of the Game of Life sp that your simulation looks like this (click for video):

Some extra things you can implement:

Increase size and change the size of the screen and see what effect this has on the simulation
Press space to pause and resume the simulation
Press 1 to randomise the board again
Press 2 to clear the board
Press 3 to draw a cross shape and see how it evolves
Drag the mouse across the window to set cells at the mouse position to be alive.
Draw a glider at the mouse position. This is starting pattern that will evolve a pattern that walks across the screen
Draw a Gosper Gun at the mouse position. This is a starting pattern that will spawn creatures indefinitely
Implement the cell coloring algorithm! This code will allow you to calculate the average of the 2 surrounding cell colors.

public float averageAround(float[][] board, int row, int col)
    {
        float xsum = 0;
        float ysum = 0;
        for(int r = row - 1; r <= row + 1 ; r ++)
        {
            for(int c = col - 1 ; c <= col + 1 ; c++)
            {
                float color = getCell(board, r, c);
                if (!(r == row && c == col) && color != -1)
                {
                    
                    float angle = map(color , 0, 255, -PI, PI);
                    xsum += cos(angle);
                    ysum += sin(angle);
                }
            }
        }

        xsum /= 3.0f;
        ysum /= 3.0f;

        return map(atan2(ysum, xsum), -PI, PI, 0, 255);
    }

Week 4 - Arrays

Recording

Lab

Learning Outcomes

Iterate over an array using for loop
How to visualise elements
Map values in a dataset onto screen coordinates
Improved computational thinking skills
Learn Java syntax

Accept this assignment on Githuib classroom. Clone the repo. Attempt the exercises and make 5 commits. Feel free to play with hue and saturation in addition to hue. Share pictures on Discord! They are really great and so impressive.

Check out this video of the assignment I wrote in GWBasic for the statistics module in first year WMT in Kevin St in 1990 (click the image for video):

And here is the source code. It's the early work of the word's greatest computer scientist.

Inspired by the video, write code to generate graphs of the rainfall data. Start with the file Arrays.java. You will find these much easier if you use the map function

Ensure your code works, if you change the drawing window size, or the array values.

A bar chart (Easy):

Start by drawing the axis, then draw the ticks and print the text, then draw the bars. You can use textAlign(CENTER, CENTER) to align the text Use the HSB color space to assign different colors to each bar
A trend line (Medium)

This one is a bit trickier, because you have to calculate the start xy, and end xy for each line. Your for loop for drawing the trend lines can start at 1 instead of 0, and then you can get the previous value for the start of each line by taking rainfall[i - 1].
A pie chart (Hard)

You can use the the arc function to draw arcs, and sin & cos to calculate the x and y coordinates to print the text. This one is the most challenging. Remember that a pie chart shows the proportion of each data point in the sum of all the data, so you will have to calculate the sum of all the rain fall and figure out how much each month is relative to the sum. It's best to draw the segments first and then draw the labels. Your map function might look something like this:
```
 float angle = map(rainfall[i], 0, sum, 0, TWO_PI);
```

Week 3 - Loops

No lecture because of bank holiday

Lab

Learning Outcomes

Learn how to use the for loop in Java
Improved problem solving ability
Improved computational thinking skills

Share screenshots on discord PLEASE. Today we will make multisensory for loops. In other words, loops that stimulate our senses with colours, hues and sounds.

Accept this individual assignment on github classroom. Clone the repository locally and make at least 5 commits as you go. Put your code into MultiSensoryForLoops.java. Have the keys 0-9 switch the screen to each of the patterns below. The color space is set to HSB and the color values correspond to hue (color), saturation (amount of gray) and brigtness. Use the Processing reference. Use mouseX, mouseY, width and height variables.

Use line, sin and cos to draw regular polygons like squares, pentagons, octogons etc:

Bonus!

Make your patterns interactive with the mouse.

Use a for loop to play a sequence of tones at different pitches. This article explains how.

Week 2 - Java Fundamentals & Drawing

Lecture

Recording

Lab

Learning Outcomes

Practice drawing stuff and working out co-ordinates
Practice using variables and if statements in Java

Share screenshots on discord PLEASE. BugZap was a game for the BBC Micro around 40 years ago, today YOU will recreate it. Just get as much as you can working in a couple of hours and commit as you are going along. Work together and help each other! Work in a group if you want to combine your work and get practice with git.

This is a video of a game the game made in Java using the Processing libraries.

How you should do it:

Accept the assignment on github classroom.
Clone the repo onto each team members computer
Each team member make commits as you are working along

Ok let's get the main game working first and not worry about the splash screen and the game over screen

There is a class called BugZap.java. Thats where you will be working today
Make sure everything works by compiling and running your program before continuing!

Now we can draw the bug.

Make fields of type float in the BugZap class for playerX, playerY and playerWidth and give these default values. You can decide what these should be. There are built in variables called width and height that give the width and height of the drawing window. These only get assigned after size has been called, so if you want to use these to give values to playerX, playerY etc. put the code into the setup method.
Write a method called void void drawPlayer(float x, float y, float w) that draws the player character, centered around the parameters x, y. You can use the line method to do this. You can pass variables as parameters to this method and also things like x + 20, w * 0.5f etc. I made an extra variable in this method called h for the height and set it to be half the w parameter. Don't forget to set the stroke color!
Call this method from draw, passing in the parameters playerX, playerY and playerWidth.
Compile and run everything to make sure it's working before continuing.
If everything is working ok, you should see the bug on the screen

Now lets get the player moving in response to the keys

public void keyPressed()
	{
		if (keyCode == LEFT)
		{
			System.out.println("Left arrow pressed");
		}
		if (keyCode == RIGHT)
		{
			System.out.println("Right arrow pressed");
		}
		if (key == ' ')
		{
			System.out.println("SPACE key pressed");
		}
	}

If you compile and run the program again you will see that some messages get printed out when you press various keys. If you are running in Visual Studio Code, you will see these messages appear in the Debug Console
Modify this method to increment and decrement the playerX variable instead and you should be able to get the player to move left and right
You might want to add if statements to this method to stop the player moving off the left and right side of the screens. If statements in Java are almost the same as in C!
When the player presses SPACE you will want to draw a line for the player's laser.

The Bug

In a similar way to how you made the player, make the Bug. Make variables and drawBug method. Don't forget to call the method from draw()
To move the bug you can add a random amount to it's x coordinate on intervals. To generate a random number you can use the random function.
One way to make stuff happen on an interval rather than every frame is to use the frameCount variable. This variable is a field in PApplet and it gets incremented automatically every time draw is called. Because draw gets called 60 times a second, you can do something every second with this code:

if ((frameCount % 60) == 0)
{
    // Do something
}

You can print text to the screen using the text function.

Ok you should now have the basics working. See if you can figure out how to check to see if the player hits the bug, add scoring, splash screen, game over screen and sound.

Week 1 - Introduction

Lecture

Tutorial

Coding Bat

Lab

Learning outcomes

Set up Java, Visual studio code and the Java Extensions
Fork the repo, configure the upstream remotes
Write your first Java Program
Test out Github classroom

Part 1 - Setup Java, forking and cloning

Install the software you will need for this module and set up your path to the Java Development Kit. This document explains what you need.

Fork this repository by clicking the fork button above, so that you get your own copy of the course repo to work on this semester. Now create a new empty folder on your computer somewhere right click on the folder and choose git bash here. Alternatively you can start the bash and cd to the new folder. To clone the repository for your fork:

git clone https://github.com/YOURGITUSERNAME/OOP-2024

Replace YOURGITUSERNAME with your github username. You can also copy the URL to the repo from your browser and paste it into the console. To paste into the bash on Windows is right click. You can use Cmd + C, Cmd + V on the Mac.

Now cd into the repo and check the origin and upstream remotes are set up correctly

cd OOP-2024
git remote -v

You should see something like this:

origin  https://github.com/YOURGITUSERNAME/OOP-2024 (fetch)
origin  https://github.com/YOURGITUSERNAME/OOP-2024 (push)
upstream  https://github.com/skooter500/OOP-2024 (fetch)
upstream  https://github.com/skooter500/OOP-2024 (push)

If you don't see the upstream remote, you can set it up by typing

git remote add upstream https://github.com/skooter500/OOP-2024

You can read more about forking a git repository and setting up the upstream remote in this article

Once the upstream is setup, you will be able to push code to your own repo and also keep it up to date with the master branch of the changes I make each class.

If you already forked the repo before the lab, you may need to update your master branch from my master branch to get the changes I made:

git fetch
git checkout master
git pull upstream master
git push

Open the OOP-2024 folder in Visual Studio Code. You can run your program by choosing Run | Start Debugger. Important for users of the Lab computers In the labs you should use the shell scripts compile.sh and run.sh located in the Java folder to compile and run your code. You can run these from the Bash.

You should see

Hello world
Woof. I am Misty
Woof. I am Lucy
cats are from space

Congratulations! You have successfully compiled and run your first Java program.

Part 2

Accept this assignment on Github classroom

You can open it in Codespaces or clone the repo and open on your computer.

Submit your solution by doing a commit

Create a Cat class
Make a private int field on the Cat class called numLives.
Write public accessors for the field (see how I did this for the name field on the Animal class)
Set the value of this field to 9 in the Cat constructor
Write a method (functions are called methods in Java) on the Cat class called kill. It should subtract 1 from numLives if numLives is > 0 and print the message "Ouch!". If numLives is 0, you should just print the message "Dead"
Create a new instance of the Cat class like this
```
Cat ginger = new Cat("Ginger");
```
In the Main class in a loop, call kill on ginger until ginger is dead.
Compile and run your program until you have no bugs and you get the desired output.

Commit and push your changes:

git add .
git commit -m "killing the cat"
git push