Learning Java with Games

571 Pages·2018·10.69 MB·English

by  Chong-wei Xu

Chong-wei Xu
Learning Java
with Games
Learning Java with Games
Chong-wei Xu
Learning Java with Games
Chong-wei Xu
Kennesaw State University
Kennesaw, GA, USA
Additional material to this book can be downloaded from http://extras.springer.com.
ISBN 978-3-319-72885-8 ISBN 978-3-319-72886-5 (eBook)
https://doi.org/10.1007/978-3-319-72886-5
Library of Congress Control Number: 2018933068
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Preface
Developing innovative teaching approaches have been one of the important topics in develop-
ing computer science curriculum. An innovative teaching approach has two important aspects.
One is that the teaching method should be able to let students see the effects of their program-
ming efforts immediately so that programming will engage students and attract their attention;
the other is that the contents of materials would have a connection with the real world, espe-
cially with the industry setting.
In order for students to easily see the effects of their programming efforts, many different
approaches have been developed, such as the robot approach, the multimedia approach, the
gaming approach, the virtual reality approach, and the like. For connecting with the real world,
the more industry-oriented materials have emerged. In order to support these new teaching
approaches, we would like to develop teaching materials that emphasize on visualization and
animation with practical flavor. Hence, video game development is our choice.
A video game is an integration of humanity, mathematics, physics, arts, artificial intelli-
gence, graphics, visualization, animation, sounds, images, programming, and so on. Therefore,
discussing all these fields in the video game context will further encourage students to have a
passion for sciences, especially for mathematics and physics. In addition, game industry is
developing rapidly. Video game development connects with industry setting ever more so than
before. The size and complexity of a video game can be tailored for students to handle and a
video game can be further extended by imagination without boundaries. For implementing a
video game, all features of object-oriented programming (OOP) and component-oriented pro-
gramming (COP) can be applied. Consequently, video game development is not only for creat-
ing games with fun but also a well pedagogical method for teaching OOP and COP.
Video game development is a vast topic covering many areas. We would like to focus our-
selves to the 2D video games with the purpose of teaching OOP programming technologies.
Video game development is challenging because it is really a problem solving process. It really
is a great topic for training brainstorming and logic thinking. Meanwhile, learning program-
ming is by doing. Consequently, the key approach for solving problems is practice. As people
say, “Practices make perfect.” Fortunately, video games have a special key feature: interactiv-
ity. Interactively talking with a video game and interactively developing and ultimately playing
the developed video game will engage students’ imagination and keep their attention fully.
Specifically, this book intends to teach Java programming through the developments of
video games. That is, learning Java programming is the goal and video games are the topic. In
addition, the book tries to build up software architecture for video games so that after students
finish this book, they will be able (1) to familiarize themselves with the Java language for pro-
gramming; (2) to develop a general architecture for video games; (3) to increase the ability
forward analyzing problems and solving problems. Usually games are decorated with many
beautiful images. In order to reduce the complexity, the book is not going to use many images,
but concentrates on the technical aspects of programming.
v
vi Preface
Organization of the Book
The book has 24 chapters that are divided into four parts.
Part I Foundation with Games In-Text: Chaps. 1–4
Java is an object-oriented programming language. That is, the language takes objects as its
building units and through the interactions among objects to perform a certain function. A
video game is a program in general, which consists of multiple objects. A video game always
has an interesting story in particular, which is full of dynamic interactions among objects.
Therefore, Java language features are very suitable for realizing video games and video games
will fully demonstrate the features of Java language. This part introduces the concepts and
essential programming elements of Java language through examples of games-in-text.
Chapter 1 Java Programming and Game Development: A project HelloWorld
Video games are programs. The interesting and engagement of game programming would
release “tedious” feeling of the program writing. Games fulfill objects and interactions among
objects that fit with the Java object-oriented features. Furthermore, game promotes experiential
learning, inquiry-based learning, self-efficacy, goal setting, and cooperation. All of these
encourage us to study Java through the construction of games.
Chapter 2 Basics of Java Programming: A Project PrintXmasCard
The simplest program HelloWorld is developed to introduce the fundamental concepts and
practices of variables, methods, and classes. And then, the project PrintXmasCard demon-
strates user input mechanism, file accesses, and exception handling. Further, primitive data
types are summarized and the built-in class String is taken as an example of reference data
type. These essentials support the basics of Java programming.
Chapter 3 OO Programming Principle: A Game In-Text GuessInt
Games in-text are simple games since they deal with Strings only. A game GuessInt is played
by two players. An initializer thinks of an integer in mind; a player guesses what it is. Java
operators are employed to form assignment, if-then-else, and loop statements to support the
actions of the initializer and the player in the format of methods. Meanwhile, the reactions
among methods accomplish the communications between them.
Chapter 4 UML and Its Usage: A Game WheelFortune In-Text
Multiple objects are reflected in a program as multiple classes. The relationships among mul-
tiple classes play a “glue” role for constructing a system. They should be clearly illustrated
through a UML class diagram. A game WheelForture-in-text deals with seven classes. A UML
class diagram illustrates its structure; a pseudo code describes “what” should be done; finally
a source code is implemented.
Part II Games Based on Event-Driven: Chaps. 5–10
Games-in-text explore the special features of games through the employments of simple pro-
gramming techniques. Due to the fact that GUI is one of the “must have” units of video games,
this part starts introducing graphical painting and applies it for making GUIs of games. A GUI
mainly consists of two portions. One portion is for displaying games’ output; the other is for
accepting players’ input. The former deals with graphical painting and the latter relates with
software components and their semantic events.
Preface vii
Chapter 5 GUI Programming with Graphical Drawing: A Project
PaintXmasCard
The project PaintXmasCard demonstrates the graphical painting techniques. Two Java built-in
classes JFrame and JPanel construct the basis for painting. The built-in graphic context
Graphics provides a rich set of painting methods. In order to arrange components on a GUI, a
variety of computations are needed. In addition, one of the most important OOP concepts
“inheritance” is brought into the programming practice.
Chapter 6 Java Software Components and Event Handling: Projects
CalculatorApp and ImageSlider
Dynamic behaviors are of the spirit of games. The software components and action-event
chains provide a strategy that allows the game player to act on software components for gen-
erating events, which in turn trigger event handlers to perform embedded dynamic activities. A
project CalculatorApp demonstrates an action-event chain and a project ImageSlider illustrates
an action-event-update-repaint chain.
Chapter 7 Event-Driven: Adding a GUI for the Game Anagram In-Text
Applying the event-driven technique for the game Anagram enriches a game-in-text with a
GUI. The GUI provides a board for displaying dynamically changed output in text and equips
the game with software components in order to allow the player inputs data and actions for
triggering events to update the state of the game and repaint the GUI after updating. This kind
of games is event-driven instead of a continuous “while” loop driven.
Chapter 8 Event-Driven with an Update-Repaint Chain: A Game Blackjack
The game Blackjack further illustrates the event-driven strategy. Its output board not only dis-
plays text but also more complicated graphics and images. All of activities of the game follow
the input controls issued by the player on software components. In addition, the game clearly
exhibits the abstract game model that sets apart the game GUI from the game logic but links
them together through event listeners and event handlers.
Chapter 9 Key Control: A Game Sudoku
The events of Java are broadly divided into two categories. The events generated by software
components are termed as semantic events. The events generated by hardware mouse or keys
are termed as low-level events. The game Sudoku is a famous numerical game played by a
single player. It is taken as an example for exposing the event listeners of keys. The player uses
keys to browse and fulfill required digits onto the board of GUI.
Chapter 10 Mouse Control: A Card Game Agnes
The other low-level events generated by mouse are adopted for controlling a card game Agnes.
In general, mouse is the best device for navigating a two-dimensional space and mouse event
listeners provide a rich set of event handlers. The Agnes is a card game played by a single
player. The cards in the GUI not only for echoing the dynamic behaviors of the game but also
play the role of input mechanism.
Part III Games Based on Animation: Chaps. 11–21
Event-driven produces discrete action-event-update-repaint chains. When these chains become
continuous, the consequent update-repaints form an illusion of animation, which drives some
components of a video game continuous independently animated. These animated components
are termed as sprites. The interactions of these animated sprites cause collisions, which in turn
trigger new events that dynamically changing the scenes of the game. The game players are
viii Preface
trying to guide or avoid collisions for reaching the goal of the game. These games are animation-
driven. This part starts the animation mechanism and builds up a three-layer software structure
for games, which is then adopted as a template for developing video games.
Chapter 11 Animation Programming: A Digital Clock and an Analog Clock
All of video games consist of sprites that are independently animated objects. The animation
needs a thread. Java provides a built-in class Thread that can be constructed as a game loop to
animate sprites. The game loop consists of three steps: updating attributes of sprites, repainting
the updated sprites, and pausing for a while. Through a digital clock and an analog clock, the
game loop and the animation programming are introduced.
Chapter 12 Merging Visualization, Event Driven, and Animation: A Game
WheelVideo
Applying the Thread and the game loop, the game WheelForture-in-text (Chap. 4) is enriched
with animation. The GUI has three pieces: a board, a player panel, and an animated wheel. The
three pieces cover the three general techniques of visualization, event-driven, and animation.
They are needed for almost all of video games. The synchronization of the three pieces is illus-
trated through a UML sequence diagram.
Chapter 13 Animated Sprites and Collisions: A Game Pong
The animated sprits cause collisions with each other or with static objects. The collisions intro-
duce a new concept and new technique of collision detection and collision handling. The player
of a game just follows the game rule to control the sprites in order to prevent collisions or to
engage collisions for dynamically changing the game states and scenes. The simple game Pong
just starts the introduction of sprites and their animations.
Chapter 14 Multiple Screens: An Extension of the Game Pong
Besides the main screen GUI, usually a game requires multiple screens, such as, splash screen,
setting screen, and the like. For organizing multiple screens, the Card layout manager in Java
is applied. Then, the game Pong is extended through adding a splash screen and more features,
such as, increasing the number of bouncing balls with different animation speed even changing
the objective of the game from bouncing to catching balls.
Chapter 15 A Three-Layer Software Structure for Games: A Game
PongStruTwo
The extensions of the game Pong explore a fact that the number of sprites and their behaviors,
as well as the complexity of the game could be dynamically changed. We need not only new
technologies but also a stable software structure for accommodating these changes. Based on
the OOP techniques of inheritance, abstract class, and polymorphism, a three-layer software
structure is constructed as a template for developing video games.
Chapter 16 Usage of the Three-Layer Structure for Games: A Project SymBall
and a Project Tornado
A project SymBall is developed for demonstrating the power of the three-layer software struc-
ture for games. The framework has a well-formed structure. Its higher layer allows adding
more levels of threads. Its lower layer has a sprite inheritance hierarchy for easily inserting
different kinds of sprites and increasing any number of sprites. In addition, another project
Tornado further illustrates the stability and flexibility of the framework.
Chapter 17 Image Sprite and UML State Machine: A Game Breakout
Since then, the three-layer software structure for games becomes a software template for
developing new video games. We can simply copy the framework to be the basis of a new
video game; and then insert the required sprites. The rudimental game Breakout is just based
Preface ix
on this strategy. The game also replaces all of sprites with images and introduces the UML
state machine to analyze and synthesize game’s dynamic activities.
Chapter 18 Sound Effect and Composite Class: Enriching the Game Breakout
To enrich the rudimental game Breakout (Chap. 17), more functions, such as, the score, the
counter for the ball-lost, the composite class, and the like are added. Among them, the sound
effect is an important piece for all of video games. By adding the sound routines, the template
of the three-layer structure for games, GameStruTemplate, is accomplished. It can be the basis
for all of video games.
Chapter 19 Changing the Structure of Sprites Dynamically: A Game Worm
The number of sprites and their moving directions are dynamically changed when the game
Worm is in execution. It requires a dynamically changeable data structure during the run time.
The special “cyclic array” with a linked list feature is applied for supporting the needs.
Furthermore, an auto-worm is added to compete with the player-controlled worm and several
extensions are proposed for raising the complexity of the game.
Chapter 20 Chess-Like Games: A Game Othello
A chess-like game Othello is introduced to illustrate games played by two players. The game
deals with new techniques, such as, to control the take-turn actions between two players, to
browse the board, to flip the pieces, etc. The more crucial issue is to physically separate the
GUI unit from the logic unit but logically link them together as a complete game. It realizes
loosely coupled software following the abstract model of games.
Chapter 21 An Introduction of Artificial Intelligence: Extensions of the Game
Othello
The further improvements of the game Othello bring up new ideas. For example, replacing the
drawing pieces with the image pieces brings image transparency and frame based animation;
switching two players version to single player version introduces artificial intelligence con-
cepts and practices. New developed artificial intelligence algorithms include “first”, “random”,
“best”, and “edge”.
Part IV Serious Games: Chaps. 22–24
Games are not only for entertainments. A category of games is termed as “serious games” that
are simulations of real-world events or processes designed for the purpose of solving a prob-
lem. Their main purposes are to train or educate users, though they may have other purposes,
such as marketing or advertisement. Serious game will sometimes deliberately sacrifice fun
and entertainment in order to achieve a desired progress by the player. We take two examples
in CS courses for illustrating the ideas about serious games. These examples also further
approve the usefulness of three-layer software structure for games.
Chapter 22 Visualizing Sorting Array Algorithms
Video game techniques are welcomed in many different fields. An effective approach for
teaching data structures is to illustrate algorithms with dynamical actions in a multimedia for-
mat. Multiple algorithms, such as inserting data, deleting data, and sorting data in one-
dimensional array are dynamically visualized through gaming techniques based on the
three-layer software structure for games.
Chapter 23 Animating Conversions Between Binary and Decimal
Binary number computations sometimes are a tough topic in oral description and tedious illus-
tration in using black board. Treating numbers as sprites with animation, we can repeatedly
x Preface
demonstrate binary computation processes. It not only reduces teacher’s burden but also
enhances students’ learning. This chapter covers the conversions of binary integers to decimal,
decimal integers to binary, as well as floating numbers.
Chapter 24 Animating Binary Arithmetic Computations
The binary number notation was evolved from signed-magnitude notation to one’s comple-
ment notation, and finally to two’s complement notation. The reason of such an evolvement
lies on the disadvantages of one notation and the advantages of the other. Projects that dynami-
cally demonstrate the three notations with their corresponding arithmetic summation processes
supply a visual tool for a better learning.
Appendix: The Source Codes of the Three-Layer Structure
for Games—GameStruTemplate
For easier studying and accessing the three-layer software structure for games, the source code
of the GameStruTemplate is duplicated under the source codes “Appendix”. This source code
is the same as the source codes in Chap. 18.
Special Features of This Book
This book is a textbook for learning Java programming. The book intends to teach Java pro-
gramming with the target of video games. Due to the fact that the video games emphasize on
problem solving, the book goes through video games’ logic analysis, state chart illustration,
algorithm design, and loosely coupled software construction for introducing the Java language
as well as programming knowledge and skills in such a way to practice “learning by doing”.
In addition, multiple topics, such as, mathematics, graphics, artificial intelligence, and pro-
gramming are merged. Game programming always promotes students with curiosity to ana-
lyze, to imagine, and to solve new challenges. Hopefully, the interesting of video games will
engage and attract students to learn more effectively and more thoroughly in the process of
finding solutions for solving problems.
Who Should Read This Book?
The book is written for the beginner of Computer Science students in mind. It could be used
for CS1 or CS2 courses. In considering the complexity of video games, the book is also suit-
able to be reference book or further-reading book for CS1 and CS2 courses. It could also be
textbook for junior or senior gaming courses or for graduate students in learning Java as the
second programming language. The book also has practical values in learning either Java pro-
gramming or game programming for different levels of readers.
The IDEs That Reader May Select
Manually editing, compiling, and executing a Java program is a tedious work. Using an IDE
will make our work easier. The better IDEs for writing Java programs includes Eclipse,
NetBeans, or others.
We used NetBeans for developing example projects in this book because NetBeans pro-
vides a utility “Print to HTML…” under the menu “File”, which can print the source code with
line numbers on a browser and the printed source code with line numbers are easy to be copied
and pasted for writing the book. For programming, any IDEs for Java are good.
In using NetBeans, readers can directly load all of book’s example projects onto the IDE
with the menu item “Open Project…”, and then compile it and run it. If using other IDEs, the