[JAVA][Beginning Java 8 Games Development]

Chapter 8 ■ Creating Your Actor Engine: Design the Characters for Your Game and Define Their Capabilities
These five variables or attributes hold the “core” properties for any sprite; the spriteFrame ImageView and the
List ArrayList of Image assets (one to many visible states) that it holds (this defines what the sprite looks
like), the spriteBound collision Shape area (defines what is deemed to have intersected with the sprite), and the X, Y
location of the sprite on the display screen.
These are also the five variables that will be configured using your Actor() constructor method, as well as your
Hero() constructor method later on. First we will create the Actor() constructor; after that, we will add in all the other
variables that we will need every Actor subclass to include.
After we create all of the other variables for the Actor class, which are not set using the Actor() constructor method,
we will initialize these to hold their default values inside of the constructor method, and finally we will have NetBeans
create .get() and .set() methods for our variables using an automatic coding function which you’ll really like.
The parameters that we will code to pass into this Actor() constructor will include the String object named
SVGdata, which will contain a string of text defining the SVGPath collision shape, as well as the sprite X, Y location, and
a comma delimited List of Image objects. The SVGPath class has a .setContent() method that can read or “parse” raw
SVG data strings, and so we will use this to turn the String SVGdata variable into our SVGPath collision Shape object.
We will not be implementing the collision code, or SVGPath Shape object during this chapter, or the next for
that matter, but we need to put them in place, so we can use them later during Chapter 16 on collision detection
processing and how to create collision polygon data using the GIMP and PhysEd (PhysicsEditor) software packages.
The Actor constructor method that we will be creating will follow the following constructor method format:
public Actor(String SVGdata, double xLocation, double yLocation, Image... spriteCels)
Later on if we need to create more complex Actor() constructor methods, we can “overload” this method by
adding other more advanced parameters, such as pivot point pX and pY, for instance, or the isFlipH or isFlipV boolean
values, to allow us to mirror fixed sprite imagery horizontally or vertically. Your Java code will look like the following:
public Actor(String SVGdata, double xLocation, double yLocation, Image... spriteCels) {
spriteBound = new SVGPath();
spriteBound.setContent(SVGdata);
spriteFrame = new ImageView(spriteCels[0]);
imageStates.addAll(Arrays.asList(spriteCels));
iX = xLocation;
iY = yLocation;
}
Notice that the ImageView constructor, invoked using the Java new keyword, passes the first frame (Image) of
the List ArrayList data you are passing in using a comma delimited list by using a spriteCels[0] annotation.
If you were to create an overloaded method that allowed you to set up the pivot point data, it might look like this:
public Actor(String SVG, double xLoc, double yLoc, double xPivot, double yPivot, Image... Cels){
spriteBound = new SVGPath();
spriteBound.setContent(SVG);
spriteFrame = new ImageView(Cels[0]);
imageStates.addAll(Arrays.asList(Cels));
iX = xLoc;
iY = yLoc;
pX = xPivot;
pY = yPivot;
}
As you can see in Figure 8-5, you will need to use the Alt-Enter work process, and have NetBeans code your
import statements for the Arrays class for you. Once you do this, your code will be error free.
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