Cameras and Game Controls - jMonkeyEngine 3.0 - page 89

break;
}
}
6. Let's have a look at the update method, where we will put these Booleans to
use. An update method is called automatically every frame, and we also get to
know how much time (in seconds) has passed since the last update, in tpf . We
start by storing the camera's current location and initialize a Vector3f object,
which we'll use for our movement delta as follows:
public void update(float tpf) {
super.update(tpf);
camLocation = cam.getLocation();
Vector3f tempVector = new Vector3f();
7. Next, we look to see if any of our movement Booleans are true and apply this
to tempVector as follows:
if(moveUp){
tempVector.addLocal(0, 0, 1f);
} else if(moveDown){
tempVector.addLocal(0, 0, -1f);
}
if(moveLeft){
tempVector.addLocal(1f, 0, 0);
} else if (moveRight){
tempVector.addLocal(-1f, 0, 0);
}
8. To keep the movement speed constant, regardless of the frame rate, we multiply
tempVector by the tpf , and then we also multiply it by our moveSpeed
variable. Then, we add it to camLocation as follows:
tempVector.multLocal(tpf).multLocal(moveSpeed);
camLocation.addLocal(tempVector);
9. At the end of the method, we set the camera's location to the modified stored loc-
ation as follows:
cam.setLocation(camLocation);