Game Development Reference
In-Depth Information
piece of the puzzle is trivial, so let's take a look at the world updating mechanism. We delegate
the acceleration value calculation to a method called
calculateInputAcceleration()
. Once
the world is updated, we check whether any of the three states (lives, waves, or score) have
changed and update the
scoreString
accordingly. Finally, we check whether the game is over,
in which case we enter the
GameOver
state.
private float
calculateInputAcceleration() {
float
accelX = 0;
if
(Settings.
touchEnabled
) {
for
(
int
i = 0; i < 2; i++) {
if
(game.getInput().isTouchDown(i)) {
guiCam.touchToWorld(touchPoint.set(game.getInput()
.getTouchX(i), game.getInput().getTouchY(i)));
if
(OverlapTester.
pointInRectangle
(leftBounds, touchPoint)) {
accelX = −Ship.
SHIP_VELOCITY
/ 5;
}
if
(OverlapTester.
pointInRectangle
(rightBounds, touchPoint)) {
accelX = Ship.
SHIP_VELOCITY
/ 5;
}
}
}
}
else
{
accelX = game.getInput().getAccelY();
}
return
accelX;
}
The
calculateInputAcceleration()
method is where we actually interpret the user input. If touch
is enabled, we check whether the left or right onscreen movement button was pressed and, if
so, we set the acceleration value accordingly to either −5 (left) or 5 (right). If the accelerometer is
used, we simply return its current value on the y axis (remember, we are in landscape mode).
private void
updateGameOver() {
List<TouchEvent> events = game.getInput().getTouchEvents();
int
len = events.size();
for
(
int
i = 0; i < len; i++) {
TouchEvent event = events.get(i);
if
(event.type == TouchEvent.
TOUCH_UP
) {
Assets.
playSound
(Assets.
clickSound
);
game.setScreen(
new
MainMenuScreen(game));
}
}
}
The
updateGameOver()
method is again trivial and simply checks for a touch event, in which case
we transition to the
MainMenuScreen
.
@Override
public void
present(
float
deltaTime) {
GL10 gl = glGraphics.getGL();
gl.glClear(GL10.
GL_COLOR_BUFFER_BIT
| GL10.
GL_DEPTH_BUFFER_BIT
);
guiCam.setViewportAndMatrices();
