[JAVA][Beginning Java 8 Games Development]

Chapter 11 ■ Moving Your Action Figure in 2D: Controlling the X and Y Display Screen Coordinates
What the iBagel.update() Java statement does is to call the .update() method for the Bagel object named iBagel
on every pulse event. Anything that you put into this .update() method will be executed 60 times every second. Any
other Actor object that you want processed at 60 FPS, simply add a similar .update() call to this .handle() method.
Moving the iBagel Actor Object: Coding Your .update() Method
Now we are ready to start developing the code that will move our InvinciBagel Actor object around the screen. We
will be refining this Java code during the remainder of the book, as everything revolves around this primary Actor
object, and his movement. This includes where he moves (boundaries and collisions), how fast he moves (speed and
physics), and what he looks like when he moves (animating between sprite image cels or “states”). All of this code will
originate inside of the iBagel object’s .update() method, and so we are going to start this lengthy journey by adding
some basic code that looks at the Boolean variables that are in our InvinciBagel.java class, and which hold the arrow
(or ASDW keys) key pressed and released states, and then process these states using conditional If statements. The
results of this conditional statement processing will then move the InvinciBagel character on the screen (initially,
later we will add more advanced programming logic). We will eventually make this movement and interaction more
and more “intelligent.” The first thing that we will want to do is to make the Boolean variables for up, down, left, and
right visible to the Bagel class using import static statements, as we did earlier in the chapter, to make the iBagel object
visible to the GamePlayLoop class .handle() method. The four added import static statements will look like this:
package invincibagel;
import static invincibagel.InvinciBagel.down;
import static invincibagel.InvinciBagel.left;
import static invincibagel.InvinciBagel.right;
import static invincibagel.InvinciBagel.up;
import javafx.scene.image.Image;
public class Bagel extends Hero {...}
As you can see in Figure 11-12, there are no error or warning highlights regarding this code, and we’re ready to
move on and add the conditional programming logic that will look at which of these four variables are set to true, or
KeyPressed, and which are set to false, or KeyReleased. Inside of these conditional statements we’ll place the code
that will move the iX and iY (Actor location) variables, based on the vX and vY (Actor velocity of movement) variables.
Figure 11-12. Add import static invincibagel.InvinciBagel references to static boolean down, left, right, and up
variables
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