Distributed Systems Programming MOD002681 2016-17 Sem 2 Main Coursework Assignment A Distributed Multiplayer Racing Game Element 010 (contributing 75% of overall module mark) The ultimate goal of this assignment is to develop a racing game which allows one person to fly his or her spaceship on one workstation and the other person to fly his or her spaceship on a second workstation while both individuals can view both spaceships on their respective screens in real time, the communication being managed by a multithreaded server. This will be a 2D game – the spaceships essentially race around a central asteroid. This assignment should to be developed in three stages. You can optionally work on this assignment during prac class time provided you first attempt any class specific exercises set in relation to the current weeks’ topic. The tutor will offer advice (formative feedback) which may help you better develop your final solution. Note you should not use Scala tools in the development of your code. As a rule of thumb, try to complete and demo part 1 by the end of week 6, part 2 by the end of week 8, and part 3 by the end of week 11 before submission. Part 1: Design your spaceships Using an off the shelf image editing tool of your choice (eg GIMP) create a JPEG image, 50 pixels by 50 pixels, of a spaceship viewed from above. You should create 16 versions of the image rotated around its center, i.e. one for every 22.5 degrees around the circle. Hint: create each new image from the original and NOT from a previously rotated image, as multiple rotations will have an cumulative effect on errors in the image. You will need two spaceships with the same 16 views. Make sure you can distinguish between the two. Write a Java application that spins one spaceship at a designated rate. To do this create one class inheriting from a JFrame, and add another class which inherits from a JPanel implementing ActionListener. The customized JPanel will effectively be the ‘palette’ containing the image of the spaceship. An animation can be created by rapidly displaying slightly different views of an array of images. Recent versions of Deitel & Deitel’s book Java: How to Program for example include a section on ‘Animating a Series of Images’ (if you have access, the book is also available for free via the Digital Library – a Quick Search using the terms >java deitel< should bring up the resource). General web searches should also provide sources. The recommended approach is to make each image a type of ImageIcon so that the JPanel’s paintComponent() method can render the image using method paintIcon(). The animation should be driven using a Swing Timer class (not to be confused with a Timer class from the java.util package) that can repeatedly delay execution for a designated number of milliseconds, automatically calling paintComponent() at the end of each cycle via the ActionListener whose actionPerformed method calls method repaint(). NB Do not develop a threaded solution using the Java Thread class – use of the Swing Timer class is all that is needed. Part 2: Develop the space racing arena In the second phase, create a Java application for the racing arena where you can ‘fly’ your two spaceships around around a central asteroid on one workstation. The racing arena is in a window 850 pixels by 650 pixels and uses the following code to create the arena; Color c1 = Color.black; g.setColor( c1 ); g.fillRect( 50, 100, 750, 500 ); //surrounding space Color c2 = new Color(210, 105, 30); // RGB brown mix g.setColor( c2 ); g.fillRect(150, 200, 550, 300); // asteroid Color c3 = Color.white; g.setColor( c3 ); g.drawLine( 425, 500, 425, 600 ); // start line Select four keys for each of the two players. Two keys are used to change the direction of their spaceship. A key press turns the spaceship 22.5 degrees left or right by changing the current image – I recommend you do not arithmetically rotate a single image during execution as it will create latency issues and does not naturally follow from the part 1 development. The other two keys are to change the speed of the spaceship. Since speed = distance/time, in this context the motion of the spaceship will be represented by pixel displacement/screen refresh. Use a scheme whereby speed is represented on a scale from 0 to 100. One press of a key either increases the speed by 10 or decreases the speed by 10. I recommend you develop one JFrame containing one JPanel which itself contains both the track and the two spaceship images, but you will also need a KeyListener to implement the keypresses. Write a Java application that allows two people to fly the two spaceships around the central asteroid by sharing a common keyboard with different sets of keys. You may add additional graphical features to make it visually more interesting. Factors to consider include how a change in direction is implemented, how a change in speed is implemented, how you might implement collision detection between a spaceship and the edge of the asteroid or the outer edge of the arena (a forcefield barrier). Ideally in the event of a collision with the asteroid/barrier the spaceship’s speed becomes 0 whilst the other spaceship proceeds, unless they collide with each other, in which case the game is ended. You could even associate sound effects with these events (eg. http://simplythebest.net/sounds/ contains some free sound clip files). Part 3: Race the spaceships on two workstations The idea here is to create a client/server application, i.e. a server and two clients where each player drives one spaceship on each client and races against the other player whose spaceship is also displayed on the corresponding client. General issues: At some stage you should test your application on a network; for example you could access other machines by simultaneously logging into different machines, either via multiple instances of your own login or with help from a colleagues’ login. Load the server software on one machine and a copy each of the client software onto two other machines (if accessing via a colleagues’ account, make sure you delete any files you have copied). Note it is entirely possible for testing purposes to undertake all development on one machine; for example run two clients and the server from three separate console windows, or perhaps with one of the instances from JGrasp. Many issues must be considered when designing a client/server application; some general questions are listed below applicable to any client/server application (emboldened) followed by a comment specific to this project; 1. What functionally is performed on the server? Does the server need to interact with a database or legacy software? Does it provide centralized services? In this 3rd part you should use as much of part 2 code as possible. Therefore, the two clients perform most of the functionality. The server only provides the communication pipe between the two clients. Only the server needs to be threaded if you use a Swing Timer class in the client (which guarantees a regular screen update). 2. What functionally is performed on the client? What user interface needs to be provided? A user can only control his or her own spaceship with four keys. When one person flies his or her spaceship, the motion of the spaceship should appear on both workstations’ screens. If the two spaceships collide, the game is over and both clients need to be notified. Allow either player to restart or exit the game from a menu. 3. How many clients? And what categories of clients? In this scenario we have two clients. 4. What message protocols are needed? What does each type of message look like? What events cause a message? Does the application need a secure channel? You will need to give careful thought on how to do this. Ignore the issue of security. 5. How to get the application started? Is authentication of clients/users needed? You will need to start the server first. Then allow either client to connect one after the other. After both clients have connected and the images of the spaceships are loaded, you will need a way to start the race. 6. How to close the application down? If a user exits in the middle of a race, the client should inform the server then the server can inform the other client to exit as well. 7. How many applications can run simultaneously? Here we assume only one game with two clients (2 spaceships racing) at a time. 8. How to coordinate the server and the clients? You can't have a client send a request and the server not respond. If you do, the application will lockup. Assignment Submission You should hand in; 1. Source and compiled code for all three parts in three separate folders on a removable media (CD or DVD). 2. Your hard-copy documentation which should also be in three sections, each section reflecting the three parts of the assignment. Submit to the Cambridge iCenter (or via equivalent partner submission process) by the last teaching day of Semester 2 (Friday 5th May 2017). In each section present a brief description (about 200 words) evaluating any items of interest related to your development (eg spaceship graphics, arena/map detail, display update, implementation of networked version). Even if any part was not completed or unsuccessful the work should be critically appraised. Each section should also contain a print-out of the relevant code (landscape, courier new, 12pt, single line spaced). It is likely some of the code will be duplicated between parts 1, 2 and 3, however you do not need to duplicate the print out of such code (although it should be duplicated in the electronic on-disk versions). The brief descriptions for each section should overall sum to no more than 600 words in total. 3. Instructions for set up and running each of the three applications (a couple of sentences in each case). Reassessment Should you be unfortunate enough to require a reassessment for this item of assessment, please submit another attempt by the standard due date for Semester 2 2016-17 resubmissions. You should consider developing alternative strategies from your first attempt to achieving a solution, if applicable. DSP assessment 2016-2017 sem2 Assessment and feedback Personalized electronic feedback by email will summarize marks/grades using this table. Component Typical Criteria Contribution Mark Part 1 Design the spaceships D 2-sets of 16 50x50pixel images created. No documentation. 20% C Spaceship rotates at nominal speed, but noticeably fluctuates in size. Little design rationale. Instructions included. B Spaceship rotates successfully. Clearly coded but with some code redundancy. A Spaceship rotates smoothly. Excellent design rationale. Part 2 Develop the racing track arena D Application displays arena and spaceships but spaceships do not move. No instructions for running the program, No description of program limitations. 45% C Application runs on one computer with one spaceship successfully manipulated with 1 set of 4- keys. Design rationale included. B Application can be run on one computer with two spaceships manipulated with 2 sets of 4 keys. Good code layout with appropriate classes. A Arena enhancements, transparent background to spaceship images, collision strategies implemented (eg spaceship/spaceship; spaceship/asteroid; spaceship/outer forcefield), sound effects, choice of spaceships/arenas. Description includes enhancements. Part 3 Race the spaceships on two workstations D Server program developed but completely unfunctional. No rationale for design. 35% C Two clients connect successfully to the server but unfunctional server threading with no communication exchange of spaceship data. No connection instructions. Well commented code. B Application partly successful with 2 clients and server but with noticeable latency effects. User interface facilitates connectivity options. A Application can be successfully run between three instances (2 clients and an efficiently threaded server). Excellent description/rationale of program. Comment: Total / Overall Grade 010 =