Android Invaders: The Grand Finale - Beginning Android Games - page 613

import com.badlogic.androidgames.framework.gl.SpriteBatcher;
import com.badlogic.androidgames.framework.impl.GLScreen;
import com.badlogic.androidgames.framework.math.OverlapTester;
import com.badlogic.androidgames.framework.math.Rectangle;
import com.badlogic.androidgames.framework.math.Vector2;
public class GameScreen extends GLScreen {
static final int GAME _ RUNNING = 0;
static final int GAME_PAUSED = 1;
static final int GAME_OVER = 2;
As usual, we have a couple of constants for encoding the screen's current state.
int state;
Camera2D guiCam;
Vector2 touchPoint;
SpriteBatcher batcher;
World world;
WorldListener worldListener;
WorldRenderer renderer;
Rectangle pauseBounds;
Rectangle resumeBounds;
Rectangle quitBounds;
Rectangle leftBounds;
Rectangle rightBounds;
Rectangle shotBounds;
int lastScore;
int lastLives;
int lastWaves;
String scoreString;
FPSCounter fpsCounter;
The members of the GameScreen are business as usual. We have a member keeping track of the
state, a camera, a vector for the touch point, a SpriteBatcher for rendering the 2D UI elements,
the World instance, along with the WorldListener , the WorldRenderer (which we are going to
write in a minute), and a couple of Rectangles for checking whether a UI element was touched.
In addition, three integers keep track of the last number of lives, waves, and score, so that we
don't have to update the scoreString each time in order to reduce GC activity. Finally, we have
an FPSCounter so that later on we can figure out how well the game performs.
public GameScreen(Game game) {
super (game);
state = GAME_RUNNING ;
guiCam = new Camera2D(glGraphics, 480, 320);
touchPoint = new Vector2();
batcher = new SpriteBatcher(glGraphics, 100);
world = new World();
worldListener = new WorldListener() {
public void shot() {
Assets. playSound (Assets. shotSound );
}