[JAVA][Beginning Java 8 Games Development]

Chapter 17 ■ Enhancing Game Play: Creating a Scoring Engine, Adding Treasure and an Enemy Auto-Attack Engine
Figure 17-36. Add callAttack, spriteMove and destination variables and an if(callAttack)-else programming structure
The first thing that we’ll need to do, inside the .update() method, is add an if(!callAttack) if-else conditional
structure around the if(attackCounter >= attackFrequency) structure that we already have in place. We will leave
the attackCounter = 0; initialization statement inside of this inner loop, and we will add a spriteMoveR = 700;
and a spriteMoveL = -70; initialization statement. These will place the Enemy sprite off-screen on either side
of the Stage.
A callAttack boolean flag allows us to communicate between the .update() and the .initiateAttack methods, as
you can see, in the .update() method, after the attackCounter (timer) has allowed the player enough time to collect
his wits after enemy attacks, this callAttack variable is set to a true (attack) value. In a more complex version of your
.initiateAttack() method, you will set this callAttack variable to a false (delay attack) value, starting the attackCounter.
Let’s also make a Java code optimization and take the .setTranslateY() method call that we have twice in the
initiateAttack() method, and make just a single method call (which represents a 100% savings on usage of the Random
object’s .nextInt() method call). Once all these programming statements are in place, you can finally set the callAttack
boolean variable to a true value, so that the next time that the if(!callAttack) conditional if-else structure is called, the
else portion at the bottom of the structure will execute and will call an initiateAttack() method. This method is where
the real heavy lifting is done, as far as animating the iBeagle Enemy character onto the screen, having him pause
and fire off a shot, and then retreat off-screen before the InvinciBagel can execute (collide with) him, gaining ten
valuable scoring points.
The else part of this if-else programming structure will call the initiateAttack() function, once the callAttack
variable has been set to a true value inside of the attackCounter timer section of your conditional programming logic.
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