Add scrolling mechanics for GameScreen, show ShopScreen on new game.

src/de/teamteamteam/spacescooter/background/ScrollingBackground.java

@@ -16,6 +16,25 @@ public class ScrollingBackground extends Background {
 	 */
 	private int offset;
 
+	/**
+	 * Internal counter for update ticks. Used as a measurement to stop/start scrolling.
+	 */
+	private int updateTickCount;
+
+	/**
+	 * This guy is used as a speed divisor - it is used in a modulo operation.
+	 * 1 - Scrolling at full speed, 101 - not scrolling at all
+	 * 2 - Scrolling at half speed.
+	 */
+	private int updateFrameDivider;
+	
+	/**
+	 * Delta telling in which direction the scrolling speed will transition.
+	 * (Basically, this is being added to the updateFrameDivider)
+	 * Can be 0 (not changing), -1 or 1.
+	 */
+	private int updateFrameDelta;
+	
 	
 	/**
 	 * Default constructor.
@@ -23,6 +42,9 @@ public class ScrollingBackground extends Background {
 	public ScrollingBackground(int x, int y) {
 		super(x, y);
 		this.offset = 0;
+		this.updateTickCount = 1;
+		this.updateFrameDivider = 101;
+		this.updateFrameDelta = 0;
 	}
 	
 
@@ -33,16 +55,59 @@ public class ScrollingBackground extends Background {
 		this.scrollingSpeed = scrollingSpeed;
 	}
 	
+	/**
+	 * 
+	 */
+	public void startScrolling() {
+		this.updateFrameDelta = -1;
+		this.updateFrameDivider = 10;
+	}
+	
+	/**
+	 * 
+	 */
+	public void stopScrolling() {
+		this.updateFrameDelta = 1;
+	}
+	
+	/**
+	 * Tell whether the Background is currently scrolling.
+	 */
+	public boolean isScrolling() {
+		return this.updateFrameDivider == 1;
+	}
+	
+	/**
+	 * Tell whether the Background is currently changing the scrolling state.
+	 */
+	public boolean scrollingStateChanging() {
+		return this.updateFrameDelta != 0;
+	}
+	
 	/**
 	 * Apply the scrolling effect by updating an internal offset counter.
 	 * Reset it when we scrolled for one image length.
 	 */
 	public void update() {
+		this.updateTickCount++;
+		if(this.updateTickCount == 100) this.updateTickCount = 1;
+		if(this.updateFrameDelta != 0 && this.updateTickCount % 10 == 0) {
+			this.updateFrameDivider += this.updateFrameDelta;
+			if(this.updateFrameDelta == -1 && this.updateFrameDivider == 1) {
+				this.updateFrameDelta = 0;
+			}
+			if(this.updateFrameDelta == 1 && this.updateFrameDivider == 10) {
+				this.updateFrameDelta = 0;
+				this.updateFrameDivider = 101;
+			}
+		}
+		if(this.updateTickCount % this.updateFrameDivider == 0) {
 			this.offset += this.scrollingSpeed;
 			if(Math.abs(this.offset) > this.getImage().getWidth()) {
 				this.offset += this.getImage().getWidth();
 			}
 		}
+	}
 	
 	/**
 	 * Paint the Background. Concatenate the image if necessary, but still try

src/de/teamteamteam/spacescooter/brain/PlayerSession.java

@@ -266,7 +266,7 @@ public class PlayerSession {
 		PlayerSession.nextLevel = GameConfig.firstLevel;
 		PlayerSession.score = 0;
 		PlayerSession.secondaryWeapon = 1;
-		PlayerSession.credits = 0;
+		PlayerSession.credits = 10;
 		PlayerSession.baseHealthPoints = GameConfig.initialPlayerHealthPoints;
 		PlayerSession.baseShieldPoints = GameConfig.initialPlayerShieldPoints;
 		PlayerSession.baseShotDamage = GameConfig.initialPlayerShotDamage;

src/de/teamteamteam/spacescooter/entity/item/ItemNuke.java

@@ -26,7 +26,7 @@ public class ItemNuke extends Item {
 		while (entityIterator.hasNext()) {
 			Entity entity = entityIterator.next();
 			if(entity instanceof Enemy) {
-				((LivingEntity) entity).takeDamage(20);
+				((LivingEntity) entity).takeDamage(9001);
 			}
 		}
 	}

src/de/teamteamteam/spacescooter/level/Level.java

@@ -3,6 +3,8 @@ package de.teamteamteam.spacescooter.level;
 import java.awt.Point;
 import java.util.ArrayList;
 
+import de.teamteamteam.spacescooter.background.Background;
+import de.teamteamteam.spacescooter.background.ScrollingBackground;
 import de.teamteamteam.spacescooter.background.CloudBackground;
 import de.teamteamteam.spacescooter.background.DogeBackground;
 import de.teamteamteam.spacescooter.background.EarthBackground;
@@ -71,6 +73,11 @@ public final class Level {
 	 */
 	private boolean playerWon;
 	
+	/**
+	 * Internal reference to the background. This is useful if the background needs to be influenced due to bossfights.
+	 */
+	private Background background;
+
 	/**
 	 * EntityIterator to evaluate the state of all the existing Entities.
 	 */
@@ -93,10 +100,14 @@ public final class Level {
 	 * show the level name in a LevelHeadline.
 	 */
 	public void doBuildUp() {
-		this.spawnEntityByAvailableName(Entity.availableNames.valueOf(this.config.background), 0, 50, null);
+		this.background = (Background) this.spawnEntityByAvailableName(Entity.availableNames.valueOf(this.config.background), 0, 50, null);
 		GameScreen.setPlayer(new Player(200, 300));
 		this.backgroundMusic = SoundSystem.playSound(this.config.backgroundMusic);
 		new LevelHeadline(100,100, this.config.name);
+		//Have the background start scrolling in case it is supported.
+		if(this.background instanceof ScrollingBackground) {
+			((ScrollingBackground) this.background).startScrolling();
+		}
 	}
 	
 	/**
@@ -175,15 +186,30 @@ public final class Level {
 			this.isGameOver = true;
 			this.playerWon = false;
 		}
+		int bossEnemyCounter = 0;
 		int enemyCounter = 0;
 		int obstacleCounter = 0;
 		this.entityIterator.reset();
 		while(this.entityIterator.hasNext()) {
 			Entity e = this.entityIterator.next();
+			if(e instanceof EnemyBoss) bossEnemyCounter++;
 			if(e instanceof Enemy) enemyCounter++;
 			if(e instanceof Obstacle) obstacleCounter++;
 		}
 		
+		//If there is a boss, make sure the background is not scrolling in case it is supported.
+		//Also resume scrolling when there is no more boss.
+		if(this.background instanceof ScrollingBackground) {
+			ScrollingBackground scrollingBackground = (ScrollingBackground) this.background;
+			if(scrollingBackground.scrollingStateChanging() == false) {
+				if(scrollingBackground.isScrolling() && bossEnemyCounter > 0) {
+					scrollingBackground.stopScrolling();
+				} else if(!scrollingBackground.isScrolling() && bossEnemyCounter == 0) {
+					scrollingBackground.startScrolling();
+				}
+			}
+		}
+		
 		//use the currentIntervalIndex to determine whether there are things scheduled to spawn.
 		int currentIntervalIndex = this.config.getIntervalIndexByCurrentTime(this.levelClock);
 		if(enemyCounter == 0 && obstacleCounter == 0 && GameScreen.getPlayer().isAlive() && currentIntervalIndex == -1) {
@@ -223,48 +249,51 @@ public final class Level {
 	/**
 	 * Spawn an Entity by name on the given position.
 	 * Uses Entity.availableNames to determine the actual Entity to spawn.
+	 * Returns the spawned instance.
 	 */
-	private void spawnEntityByAvailableName(Entity.availableNames entity, int x, int y, ArrayList<Point> points) {
+	private Entity spawnEntityByAvailableName(Entity.availableNames entity, int x, int y, ArrayList<Point> points) {
+		Entity spawnedEntity = null;
 		switch(entity) {
 			case StarBackground:
-				new StarBackground(x, y);
+				spawnedEntity = new StarBackground(x, y);
 				break;
 			case CloudBackground:
-				new CloudBackground(x, y);
+				spawnedEntity = new CloudBackground(x, y);
 				break;
 			case DogeBackground:
-				new DogeBackground(x, y);
+				spawnedEntity = new DogeBackground(x, y);
 				break;
 			case EarthBackground:
-				new EarthBackground(x, y);
+				spawnedEntity = new EarthBackground(x, y);
 				break;
 			case EnemyOne:
-				new EnemyOne(x, y);
+				spawnedEntity = new EnemyOne(x, y);
 				break;
 			case EnemyTwo:
-				new EnemyTwo(x, y);
+				spawnedEntity = new EnemyTwo(x, y);
 				break;
 			case EnemyThree:
-				new EnemyThree(x, y);
+				spawnedEntity = new EnemyThree(x, y);
 				break;
 			case EnemyFour:
-				new EnemyFour(x, y, points);
+				spawnedEntity = new EnemyFour(x, y, points);
 				break;
 			case EnemyBoss:
-				new EnemyBoss(x, y);
+				spawnedEntity = new EnemyBoss(x, y);
 				break;
 			case StoneOne:
-				new StoneOne(x, y);
+				spawnedEntity = new StoneOne(x, y);
 				break;
 			case StoneTwo:
-				new StoneTwo(x, y);
+				spawnedEntity = new StoneTwo(x, y);
 				break;
 			case StoneThree:
-				new StoneThree(x, y);
+				spawnedEntity = new StoneThree(x, y);
 				break;
 			default:
 				System.err.println("I don't know how to spawn this: " + entity);
 				break;
 		}
+		return spawnedEntity;
 	}
 }

src/de/teamteamteam/spacescooter/screen/MainMenuScreen.java

@@ -23,10 +23,11 @@ public class MainMenuScreen extends Screen {
 	private int menuPoint = 0;
 	private boolean keyPressed = false;
 	private int animationStatus = 0; //0 = Animation noch nicht gestartet, 1 = Animation laeuft, 2 = Animation beendet
+	private StarBackground background;
 	
 	public MainMenuScreen(Screen parent) {
 		super(parent);
-		new StarBackground(0, 0);
+		this.background = new StarBackground(0, 0);
 		new Button(GameConfig.windowWidth/2-125, 200);
 		new Button(GameConfig.windowWidth/2-125, 275);
 		new Button(GameConfig.windowWidth/2-125, 350);
@@ -87,6 +88,7 @@ public class MainMenuScreen extends Screen {
 		// make a selection
 		if(Keyboard.isKeyDown(KeyEvent.VK_ENTER) || Keyboard.isKeyDown(KeyEvent.VK_SPACE)) {
 			animationStatus = 1;
+			this.background.startScrolling();
 		}
 		
 		if(animationStatus == 1) {
@@ -97,7 +99,7 @@ public class MainMenuScreen extends Screen {
 		} else if(animationStatus == 2) {
 			switch (menuPoint) {
 				case 0:
-					this.parent.setOverlay(new GameScreen(this.parent));
+					this.parent.setOverlay(new ShopScreen(this.parent));
 					break;
 				case 1:
 					this.parent.setOverlay(new HelpScreen(this.parent));