Tag Archives: examples

JavaFX 2 GameTutorial Part 1

SpaceshipFX

figure 1 SVG of a spaceship

Introduction

I believe most software developers at one point in their lives as a youngster (young person) may become compelled to create games to help them learn a programming languages (I know I did). Back in the day my first computer was actually a Franklin Ace 1000 and later an Apple ][. While developing games on those systems it was pretty challenging. For starters you had to learn assembly language (6502) and there were virtually little to no tools to create sprites (graphics assets). One of my favorite games that I believe was probably the first real time strategy (RTS) game was Rescue Raiders (1984).

Let’s fast forward to 2012 where computers, graphics tool kits, libraries, and game engines have come a long way since then. Many APIs will provide much of the plumbing that will shield the user of the API so that they may focus on making their games fun and exciting. Speaking of APIs JavaFX 2.x is not only a great UI toolkit to create nice looking applications, but you can make fun games. With JavaFX 2.x you will be able to create games that can kill time with hours of fun!

Growing up I was always fascinated with science fiction movies such as Star wars and Star trek. I’ve always wanted to create a simple top view display game (2D) where I could control my spaceship similar to the classic game Asteroids. However as time went by a friend shared with me the game Star Craft 1 and Brood wars I was just astonished. I really like the game play still to this very day, so I wanted to adopt some of the elements of the game such as navigating units and troops using the mouse pointer and buttons (ie: The Terran Battle Cruiser).

In this blog entry (Part 1) I will briefly explain the game play and how to navigate a spaceship using simple shapes (circles and lines). There isn’t any code to show you in part 1 (this blog entry), but a simple application to demonstrate how the ship will behave in the final game. As we progress through the series you will notice incremental changes such as cool sprites, sounds, etc. Remember the final game will just be a spaceship avoiding enemy ships and firing back with sound effects. The ship will appear like the one depicted at the beginning of this blog entry (figure 1).

I would like to create a series of blog entries (six parts) detailing tutorials to create a JavaFX 2.x game. Below is a brief summary of the series:

Part 1 – Introduction (Click here to run demo)
Part 2 – Game loop
Part 3 – Input / (Mouse, Keyboard)
Part 4 – Sprites / Collision
Part 5 – Sound
Part 6 – Concluding thoughts

Requirements & Design

  • Create a prototype of a spaceship using basic shapes.
  • Rotate the spaceship clockwise or counter clockwise depending on the screen location of a right mouse click.
  • Fire a projectile when the primary mouse button is pressed.
  • Display the mouse press (x, y) screen coordinates
  • Display angle of rotation when the ship’s nose (front of the ship) from zero degrees (0,0) to (1,0) [Cartesian system].
  • Display the direction (clockwise or counter clockwise) of the rotation of the spaceship

Shown in figure 2 is a simple prototype using simple shapes to help us focus on the math. A good principle is to create a functional prototype before investing a lot of time in drawing your graphics assets.

spaceship protype

figure 2 Spaceship Prototype

  • (MX, MY) – Mouse press (x, y) coordinate space on the JavaFX Scene.
  • (vx, vy) – End angle or mouse press(x, y) coordinate converted to Cartesian coordinates relative to the center of the ship.
  • (ux, uy) – Start angle or previous mouse press(x, y) coordinate converted to Cartesian coordinates relative to the center of the ship.
  • U’s angle: The angle of the start of the ships nose rotation. In a Cartesian coordinate system (1,0) the nose is pointing west or zero degrees. As the ship rotates counter clockwise the angle increases. When moving in a clockwise direction the rotation angle will be negative numbers.
  • V’s angle: The angle of the ships nose rotation where it should stop. In a Cartesian coordinate system (1,0) the nose is pointing east or zero degrees. As the ship rotates counter clockwise the angle increases. When moving in a clockwise direction the rotation angle will be negative numbers.
  • Direction: The rotation of the ship nose to turn the ship clockwise or counter clockwise. When clicking the mouse to turn the ship when less than 180 degrees the ship will turn towards the mouse click instead of turning the other way which is greater than 180 degrees (the long way).

Demo

Requirements:

  • Java 7 or later
  • JavaFX 2.0 or later
  • Windows XP or later (Should be available soon for Linux/MacOS)

A simple prototype of the navigation and weapon systems for the spaceship.

Instructions:

  • Right click (on Windows) mouse to fly ship.
  • Primary (left click on Windows mouse) to fire weapon.


Click here to run demo

References

Franklin Ace – Vintage Computer : http://www.vintage-computer.com/franklin.shtml

Apple ][ – Vintage Computer: http://en.wikipedia.org/wiki/Apple_II

Rescue Raiders – Wikipedia: http://en.wikipedia.org/wiki/Rescue_Raiders

Star wars – Movie Database: http://www.imdb.com/title/tt0076759/

Star trek – Movie Database: http://www.imdb.com/title/tt0796366/

Star craft – Wikipedia: http://en.wikipedia.org/wiki/Star_Craft

Star craft Brood wars – Wikipedia: http://en.wikipedia.org/wiki/StarCraft:_Brood_War

Rescue Raidershttp://en.wikipedia.org/wiki/Rescue_Raiders

JavaFX 2.0 Introduction by Example book

I recently finished writing a book on the new release of the JavaFX 2.0 SDK and it has already been placed on the shelves at a bookstore (Amazon) near you. The book will walk you through, step-by-step, giving you the ins and outs of JavaFX 2.0. When you encounter a chapter you will be presented recipes which will pose a problem (use case scenario) that will have an associated solution. After a proposed solution you will be shown an example source code listing and its display output after the program has been executed. Lastly you will be shown a section called “How it works” which will explain and discuss the examples and their details. To see more about this book, such as the source code and errata, please visit Apress Publishing (http://www.apress.com/9781430242574).

In this blog entry I also want to give you a sneak preview of a Java Webstart example of chapter 3 recipe 3-1 (JavaFX 2.0 MP3 Player). To launch the JavaFX MP3 player just jump down to Chapter 3 below.

Below is a brief overview of the chapters in the book:

Chapter 1: JavaFX Fundamentals

I begin by instructing you on how to get your environment set-up to rapidly develop rich internet applications using Java and JavaFX.

JavaFX Swiss army knife

After reading this chapter you will be able to answer questions such as:

  • How do I create GUI applications?
  • What is the Scene graph?
  • How do I display text onto the scene graph?
  • How do I incorporate UI controls into my application?
  • How do I bind expressions?
  • How do I draw shapes?
  • How do I generate a background process?
  • How do I associate keyboard sequences to applications?

Chapter 2: Graphics with JavaFX
In chapter 2 there are recipe examples which delve into JavaFX’s graphics and animation capabilities. I begin by explaining some of the basics of JavaFX’s Graphics such as rendering images and animating nodes. I then go on to more advanced topics such as animating with transitions, manipulating layouts, and enhancing nodes using JavaFX CSS.
The following picture, taken from Recipe 2-2, depicts an image viewer application with a custom news ticker control at the bottom.

Photo Viewer and News Ticker application

Photo Viewer and News Ticker application

Chapter 3: Media with JavaFX
Chapter 3 covers all things media related. Here I reveal JavaFX’s media APIs which allows you to integrate audio and video into your applications. I begin by showing you how to create a JavaFX MP3 player and a video player. Then I will walk you through the different ways to enhance the video player with additional features to control media actions and events, mark positions in a video, and synchronize animations.

The illustration below, taken from Recipe 3-1, depicts a JavaFX 2.0 MP3 player with a graphical visualization (using the AudioSpectrumListener API). Before launching the example you will need to know the requirements and instructions to run the demo example.

JavaFX 2.0 MP3 Player

JavaFX MP3 Player

Simple requirements and instructions to run the JavaFX 2.0 MP3 Player:

Requirements

  • Java 6 update 24 JRE or greater (Java 7 is preferred)
  • JavaFX 2.0 or greater (JavaFX 2.0.2 is preferred)
  • Windows XP SP 3 or greater. (I will update the jnlp as JavaFX becomes available on other OSes)

Instructions

  1. Click the Webstart launch button below.
  2. By using your file explorer on your host operating system “drag and drop” a music mp3 file onto the surface of the application.
  3. Use the controls to the bottom right of the application to pause, play, and stop the music.
  4. You may use your mouse to drag the application around your desktop.
  5. To close the application click on the ‘X’ in the upper right hand corner.

To launch the application click on the Java Webstart button below:

Demo JavaFX 2.0 MP3 Player

Chapter 4: JavaFX on the Web
In chapter 4 you will be able to take advantage of the interoperability between JavaFX and HTML5.

For starters I will cover how to embed JavaFX applications into a Web page. I then will demonstrate JavaFX’s powerful WebView and WebEngine APIs. Below are the recipe examples from chapter 4 which utilize the  WebView and WebEngine APIs:

  • Displaying HTML5 Content (animated analog clock application)
  • Loading data from a Web service (weather application)
  • Handling Web events
  • Storing and displaying data using an embedded database (RSS reader application)

Depicted below is an animated analog clock application, taken from Recipe 4-2, demonstrating the ability to render HTML5 content.

JavaFX 2.0 Analog Clock

JavaFX 2.0 Analog Clock (HTML5)

I assume you know the Java programming language and some web development concepts. I hope you will enjoy these examples which can be used freely in your own projects. I’ve tested the examples with the latest Java 7 update 2 and JavaFX 2.0.2 runtime and SDK. If you have any questions or comments feel free to ask them here or on my Twitter account @carldea .

Thanks!

Carl