Java ZeldaBy: Phillip Garber

Executive Summary

• Java Zelda is an attempt at making a remake of the classic SNES game Legend of Zelda – A Link to the Past.

• The game will come with a map editor, with a point and click interface.

• The final product will contain a database of files and maps that the program will use to create the players environment.

System Selection

• The reason for creating a Java implementation of Zelda would be to add the ability to customize features of game play.

• The user would be able to modify maps, characters/enemies, items, and sounds.

• By developing in java, I will not have to create different distributions for different platforms.

System Analysis

• Zelda for the SNES works well with tiled images.

• The map is scrollable, due to the small display size of the screen.

• The game is full of simple puzzles, and enemies to defeat.

System Design

• The new system will keep the old style for making maps, by creating an array of images.

• The player will interact with the game through the keyboard, instead of a gamepad.

System Design

• The HUD has been changed, to put the weapon information on the bottom.

• A basic map, and its map file’s contents.

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System Design

There are 11 files per map, which make up all of its layers, and effects.

• Activators• Blocker• Button• Enemy• Map• Overlay• Pickupable• Pits• Pushable• Warps• Music

Map• The basic background image that the player walks on.

Blockers

• A blocker is a wall, or impassable object for the player.

Pits• The player can fall in pits, and will be sent back to the

part of the map where they originated with lower health.

Warps

• Tiles that will warp the player to a new map, or a different section of the same map.

Activators

• An activator can be used to display a message, or unlock a door.

Pushable

• Blocks that can be pushed around to solve puzzles.

Buttons• A button is a tile that when stepped on, it unblocks

a set of blockers.

• A button can either open permanently, or while it is currently pressed.

Buttons- continued

• A button can be also pressed by pushing a block on it.

• There is an invisible button that can unblock something if it detects all enemies in the room are clear.

Pickupable

• Any item that the player can pick up.

• Can be animated, and can be set to an unpickupable state to be used as a background animated tile.

Enemies

• Enemies have several simple AI types, and attack the player.

Overlay• A layer of PNG images that are drawn on

top of all of the layers semi-transparently.

• Can be used for shadows, clouds, or anything else that would cover areas of the map.

• The overlay layer can be animated.

Music

• The music file contains the filename for the music file that will be looped in the background of the map.

• Currently, only music files less than 1MB are supported due to limitations in java’s audio, and IO classes.

Operating System Principals

• Multithreading- Many of the objects in the game run on their own thread.

• Multiprocessor Support- With elements of the game being able to run on their own thread, the program can be split up to take advantage of a multi-core CPU.

• Each of the threads are assigned a priority, which allows the Operating System to manage them if the CPU is currently being used by a lot of other processes.

Operating System Principals

• The IO in my program uses the built in reader for images, and sun’s AudioPlayer to play audio streams.

• Everything is in a respective folder to its type, and is easy to access.

• This software system currently takes up 19.4MB, and has over 1,600 files.

Operating System Principals

• The tree diagram of my program’s files.

Tiles/

Images/ Maps/ Save/ Sounds/

Map1/

SaveGame.save

Map1.act

Map1.blk

Map1.but

Map1.enm

Map1.map

Map1.mus

Map1.ovr

Map1.pik

Map1.pit

Map1.pus

Map1.wrp

……

…01.GIF

arrowHit.wav

Significance of points related to embedded operating system principals, policies,

techniques or architectures

• The game must optimized to run on any platform.

• The game must have a high, and constant frame rate.

• The game must be modifiable.

• The game must be easy to control, and the editor must be easy to use.

The game must optimized to run on any platform

• The code is written in java, which can be run on most all computers.

• The game is multithreaded, so it can take advantage of hyper-threading, or a multi-core CPU.

• Even if a computer has a standard, non-hyper-threaded CPU, it still will run.

The game must have a high, and constant frame rate

• Because everything is threaded, with priorities, the Operating System can manage the threads if the CPU gets overloaded.

• The game’s rate is controlled by a separate timing thread, which calls for a new frame 66.67 times per second.

The game must be modifiable.

• The game comes with a mapmaker.

• All of its images, sounds and maps can be edited.

• The files can be edited on the fly, while the game is running. The user just needs to walk out of the map, and back in, to have the changes take place.

The game must be easy to control, and the editor must be easy to use.

• The game uses WASD to move, E to activate objects, and R to use a weapon.

• The editor has an easy to use interface.

• The file structure makes it easy to find files, so they are not all in one giant folder.

Methodology and technology for the solutions related to embedded operating System

Principles, policies, techniques, or architectures

• Java has the Thread class, which can be extended by a custom class to allow a program to run as a

separate thread. • With the performance benefits of multithreading on a

multi-processor system, the CPU load by my program is usually within 0-2%.

• The file structure of my program allows easy access to maps, and files. This makes it easy to edit, and transfer the maps to a friend.

Sources Used• "Hyper-threading." Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 13

Nov 2007 <http://en.wikipedia.org/w/index.php?title=Hyper-threading&oldid=170417708>.

• “Java 2 Platform Standard Edition 5.0: API Specification.” Sun Microsystems, Inc. 2004 http://java.sun.com/j2se/1.5.0/docs/api/

• “Legend of Zelda Sound Effects.” Creator: “HelpTheWretched.” 2007 http://noproblo.dayjo.org/ZeldaSounds/

• “Operating Systems: Internals and Design Principals” William Stallings. Pearson Prentice Hall, Pearson Education Inc. Upper Saddle River, NJ. 2005.

• “The Legend of Zelda: A Link to the Past” Shigeru Miyamoto, Nintendo. April 13, 1992. Super Nintendo Entertainment Center.

• "Thread (computer science)." Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 2 Dec 2007 <http://en.wikipedia.org/w/index.php?title=Thread_%28computer_science%29&oldid=174109853>.