Java Games Continued: Fun with Polygons - Pro Android Games - page 102

for (i = 0; i < numStars; i++) {
// random XY Point
stars[i] = new Point((int) (Math.random() * width)
, (int) (Math.random() * height) );
}
}

The stars are created using random Point s with X and Y coordinates defined using the getWidth and
getHeight methods. Note that getWidth and getHeight are built-in methods provided by the LinerLayout
class.
Next, we create all polygon sprites in the game:

The ship

•

The ship's thrusters

•

Photons (the ship's bullets)

•

The flying saucer

•

Asteroids and asteroid explosions
Note that all elements in the game are polygons, even the tiny photons and asteroid explosions.
Finally, miscellaneous data is initialized and the game is put in Game Over mode.

•

Listing 4-6. Game Initialization

protected void initialize() {

// Load sounds
try {
loadSounds();
loaded = true;
} catch (Exception e) {
Tools.MessageBox(mContex, "Sound Error: " + e.toString());
}

// create star background
createStarts();

// Create shape for the ship sprite.
ship = new PolygonSprite();
ship.shape.addPoint(0, -10);
ship.shape.addPoint(7, 10);
ship.shape.addPoint(-7, 10);

// Create thruster shapes
createThrusters();

// Create shape for each photon sprites.
for (i = 0; i < Constants.MAX_SHOTS; i++) {