The Settings Screen
The settings screen offers the player an option to change the input method, as well as enable or disable audio. Indicate this with three different icons (see Figure 12–4). Touching either the hand or the tilted device will enable the respective input method. The icon for the currently active input method will have a gold color. For the audio icon, do the same as in the previous games.
The choices of the user are reflected by setting the respective Boolean values in the Settings class. Make sure these settings are instantly saved to the SD card each time one of them changes, via a call to Settings.save(). Listing 12–5 shows you the code.
Listing 12–5. SettingsScreen.java, the Settings Screen
package com.badlogic.androidgames.droidinvaders;
import java.util.List;
import javax.microedition.khronos.opengles.GL10;
import com.badlogic.androidgames.framework.Game;
import com.badlogic.androidgames.framework.Input.TouchEvent;
import com.badlogic.androidgames.framework.gl.Camera2D;
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 SettingsScreen extends GLScreen {
Camera2D guiCam;
SpriteBatcher batcher;
Vector2 touchPoint;
Rectangle touchBounds;
Rectangle accelBounds;
Rectangle soundBounds;
Rectangle backBounds;
As usual, have a camera and SpriteBatcher render your UI elements and the background. To check whether a touch event hit a button, store a vector and rectangles for the three buttons on screen.
public SettingsScreen(Game game) {
super(game);
guiCam = new Camera2D(glGraphics, 480, 320);
batcher = new SpriteBatcher(glGraphics, 10);
touchPoint = new Vector2();
touchBounds = new Rectangle(120 - 32, 160 - 32, 64, 64);
accelBounds = new Rectangle(240 - 32, 160 - 32, 64, 64);
soundBounds = new Rectangle(360 - 32, 160 - 32, 64, 64);
backBounds = new Rectangle(32, 32, 64, 64);
}
In the constructor, set up all the members for the screen. No rocket science involved here.
@Override
public void update(float deltaTime) {
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)
continue;
guiCam.touchToWorld(touchPoint.set(event.x, event.y));
if (OverlapTester.pointInRectangle(touchBounds, touchPoint)) {
Assets.playSound(Assets.clickSound);
Settings.touchEnabled = true;
Settings.save(game.getFileIO());
}
if (OverlapTester.pointInRectangle(accelBounds, touchPoint)) {
Assets.playSound(Assets.clickSound);
Settings.touchEnabled = false;
Settings.save(game.getFileIO());
}
if (OverlapTester.pointInRectangle(soundBounds, touchPoint)) {
Assets.playSound(Assets.clickSound);
Settings.soundEnabled = !Settings.soundEnabled;
if (Settings.soundEnabled) {
Assets.music.play();
} else {
Assets.music.pause();
}
Settings.save(game.getFileIO());
}
if (OverlapTester.pointInRectangle(backBounds, touchPoint)) {
Assets.playSound(Assets.clickSound);
game.setScreen(new MainMenuScreen(game));
}
}
}
The update() method fetches the touch events and checks whether a "touch-up" event has been registered. If so, it transforms the touch coordinates to the camera's coordinate system. With these coordinates, it tests the various rectangles to decide what action to take.
@Override
public void present(float deltaTime) {
GL10 gl = glGraphics.getGL();
gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
guiCam.setViewportAndMatrices();
gl.glEnable(GL10.GL_TEXTURE_2D);
batcher.beginBatch(Assets.background);
batcher.drawSprite(240, 160, 480, 320, Assets.backgroundRegion);
batcher.endBatch();
gl.glEnable(GL10.GL_BLEND);
gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
batcher.beginBatch(Assets.items);
batcher.drawSprite(240, 280, 224, 32, Assets.settingsRegion);
batcher.drawSprite(120, 160, 64, 64,
Settings.touchEnabled ? Assets.touchEnabledRegion : Assets.touchRegion);
batcher.drawSprite(240, 160, 64, 64,
Settings.touchEnabled ? Assets.accelRegion
: Assets.accelEnabledRegion);
batcher.drawSprite(360, 160, 64, 64,
Settings.soundEnabled ? Assets.soundEnabledRegion : Assets.soundRegion);
batcher.drawSprite(32, 32, 64, 64, Assets.leftRegion);
batcher.endBatch();
gl.glDisable(GL10.GL_BLEND);
gl.glDisable(GL10.GL_TEXTURE_2D);
}
The render() method does the same thing as the MainMenuScreen.render() method. Render the background and buttons with texturing and blending where needed. Based on the current settings, decide which TextureRegion to use to render the three settings buttons.
@Override
public void pause() {
}
@Override
public void resume() {
}
@Override
public void dispose() {
}
}
The rest of the class is again composed of a few boilerplate methods with no functionality whatsoever.
Before you can create the GameScreen, you first have to implement the logic and rendering of your world. Model-View-Controller to the rescue!