[JAVA][Beginning Java 8 Games Development]

Chapter 13 ■ Animating Your Action Figure States: Setting the Image States Based on KeyEvent Processing
Since this is not how we want to make our game player make the InvinciBagel run (because the very nature of it
stops his movement around the screen, and because it’s just plain lame), let’s quickly put into place your up and down
key support, so that we can come back and work on the left and right keys so we can make the run cycle work!
The InvinciBagel Fly State: If KeyPressed Set imageState(3 & 4)
The if(invinciBagel.isDown()) and the if(invinciBagel.isUp()) conditional if() structures are identical to the
left and right key structures, except that they call imageStates(3) and imageStates(4) List elements, to allow the
InvinciBagel character to “come in for landing” (cel 3), and “take off flying” (cel 4). As we add more of the imageStates
during this chapter, and combine this cel animation code with our motion and boundary code, you are going to have
more and more fun testing this chapter’s coding results! If you want to take a programmer’s shortcut, copy and paste
the .isRight() and .isLeft() constructs underneath themselves, and simply change the .get(1) and .get(2) to .get(3) and
.get(4). As you can see in Figure 13-4, the code is currently very compact and well organized; structured; and logical;
and in only half a dozen lines of Java code, we have now implemented more than half of our nine image states already!
Of course, we still have to add refinement code, to implement sprite mirroring for direction changes and run-cycle
timing refinement. The Java code for the .isUp() and .isDown() method structures should look like the following:
if(invinciBagel.isDown()) {
spriteFrame.setImage(imageStates.get(3));
}
if(invinciBagel.isUp()) {
spriteFrame.setImage(imageStates.get(4));
}
Figure 13-4. Add conditional if() statements that check for up/down movement and sets jump/land sprite image state
As you can see in Figure 13-4, our code is error-free, and we are ready to add several layers of complexity to the
left and right arrow key event processing code, since these two keys are defining the direction (East and West) the
InvinciBagel is traveling. For this reason, these two conditional if() statement structures, in particular, need to become
more complex, because traveling East (to the right) will use original (isFlipH = false) sprites, and traveling West (to the
left) will utilize a mirrored version (isFlipH = true) of each sprite, “flipping” the Image assets around the central Y axis.
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