[JAVA][Beginning Java 8 Games Development]

Chapter 8
Creating Your Actor Engine: Design
the Characters for Your Game and
Define Their Capabilities
Now that we have created the game play timing loop in Chapter 7, let’s get into some scratch coding here in Chapter 8,
and create the public abstract class framework that we can use to create the different types of sprites that we will be
using in our InvinciBagel game. This essentially equates to your “Actor Engine” for your game, as you’ll define and
design the various types of game components that your game will include as actors, and these two classes will be
used to create all of the other classes that will be used to create the objects (components) that are in your game. These
would include things such as the InvinciBagel himself (the Bagel class), his adversaries (the Enemy class), all the
treasure he looks for during the game (the Treasure class), things that are shot at him (the Projectile class), things that
he navigates over and around (the Prop classes), all providing game objectives that InvinciBagel must try and achieve.
During this chapter, we will create two public abstract class constructs. The first, the Actor class, will be the
superclass of the other, the Hero subclass. These two abstract classes can be used during the book to create both our
fixed sprites, which are sprites that do not move (obstacles and treasure), using the Actor superclass, and sprites that
move around the screen, using a Hero subclass of the Actor class. The Hero class will provide additional methods and
variables for motion sprites (the superhero, and his arch enemies in the multi-player version of the game). These will
track things like collision and physics characteristics, as well as Actor animation (motion states). Having lots of motion
on the screen will make game play more interesting, and allow us to make the game more challenging for the player.
Creating the Actor Engine up front will give you experience in creating public abstract classes. As you recall
from Chapter 3, public abstract classes are used to create other class (and object) structures in Java, but are not used
directly in the actual game programming logic. This is the reason I am terming creating these two “blueprint” classes
creating the Actor Engine, as we are essentially defining the lowest level of the game, the “actors” during this chapter.
As we progress in the design of the game during the book, we’ll create the Treasure subclass using the Actor
(fixed sprite) class, for “fixed” treasures that will get picked up by InvinciBagel during the game play. We’ll also create
the Prop class using this Actor superclass, for the obstacles in the game that InvinciBagel has to navigate up, over,
under, around, or through, successfully. We’ll also create sprites that move around on the screen using the Hero
subclass of the Actor superclass, such as the Bagel class. We’ll eventually create an Enemy class and Projectile class.
Besides designing the two key public abstract Actor classes during this chapter, we will also define our main
InvinciBagel character’s digital image states using less than ten PNG32 digital image assets. We will do this during
this chapter so that this is in place before we’ll want to use these classes and sprite image states in the next chapter
of the book, when we’ll look at event handling, so that the player can control where the InvinciBagel goes around
the screen and what states (stand, run, jump, leap, fly, land, miss, crouch, etc.) he is using to navigate the obstacles
in his world.
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