[JAVA][Beginning Java 8 Games Development]

Chapter 7
The Foundation of Game Play Loop:
The JavaFX Pulse System and the
Game Processing Architecture
Now that you have created the top-level UI screens needed for your user to learn how to play the game, start the game,
view high scores, and review the legal disclaimers and Ira H. Harrison Rubin’s InvinciBagel intellectual property game
production credits, let’s get down to business and create the game play timing loop for your InvinciBagel game. This
is of the greatest importance from a user experience standpoint, and is also critical to the proper functioning of the
different game engines that you will be creating over the course of the remainder of this book, including the sprite
engine, collision detection engine, animation engine, scoring engine, and physics engine. You will always keep
smoothness of game play in mind; the efficient, optimal implementation of the JavaFX pulse system is of paramount
importance at this stage of the game (no pun intended). For this reason, I will be going into great detail in this chapter
regarding the javafx.animation package, and how all of its functional classes differ from each other.
First, you will explore the two Animation superclasses in the javafx.animation package: Animation and
AnimationTimer. After that, you will take a look at Animation, Timeline, and Transition and how these classes, and
any of their subclasses, such as PathAnimation and TranslateAnimation, will allow you to access the JavaFX pulse
event timing system. Now, you need to use pulse, if you want to create an action-oriented arcade type Java 8 game!
You will also be taking a closer look at the overall structure of the entire javafx.animation package, because
you’ll need to use one of these classes for your Java 8 game play loop. You will do this by using a diagram of the entire
package, so that you can get an overview of how all its classes interrelate. You will then examine the class hierarchies
among all of the JavaFX Animation classes, in detail. With the exception of AnimationTimer, Interpolator,
KeyFrame, and KeyValue, all of these javafx.animation package classes are subclassed (using the Java extends
keyword) using the JavaFX Animation superclass.
Finally, you will be adding the new GamePlayLoop.java class into your invincibagel package, which will be
created as a GamePlayLoop object in the InvinciBagel.java Application subclass, implementing the timing loop. This
GamePlayLoop class will contain a .handle() method, as well as a .start() method and a .stop() method, which will
allow you to control your GamePlayLoop timing events when the GamePlayLoop is operational, and to determine
when it is latent (stopped or paused).
I will create a diagram that will show the class and object hierarchy for this InvinciBagel game, so that you can
start to visualize how these classes that you are coding, and objects that you are creating, will all fit together. It is
almost as if the coding of a game using Java 8 and JavaFX is in itself a (puzzle) game! Pretty cool stuff.
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