Complete box2d implementation, all collisions handled with box2d

Shield re-implemented as an entity with a box2d body
Multiball powerup now spawns balls at paddle instead of from block location

core/src/com/me/brickbuster/entity/Ball.java

@@ -10,10 +10,11 @@ import com.badlogic.gdx.physics.box2d.Body;
 import com.badlogic.gdx.physics.box2d.BodyDef;
 import com.badlogic.gdx.physics.box2d.CircleShape;
 import com.badlogic.gdx.physics.box2d.FixtureDef;
+import com.me.brickbuster.physics.CollisionListener;
 import com.me.brickbuster.physics.PhysicsBody;
 import com.me.brickbuster.state.PlayState;
 
-public class Ball extends Entity implements PhysicsBody {
+public class Ball extends Entity implements PhysicsBody, CollisionListener {
 
 	public static final float RADIUS = 1.2f;
 	public static final Color BALL_COLOR = Color.CHARTREUSE;
@@ -21,17 +22,56 @@ public class Ball extends Entity implements PhysicsBody {
 	public static final float BOOST_SPEED = 55;
 	public static final int BLOCKS_FOR_BOOST = 39;
 
-	public Vector2 direction;
 	private float speed;
 	private boolean isStuck = true;
-	private boolean isDead = false;
+	private boolean touchedPaddle = false;
 
 	private Body body;
 
 	public Ball(PlayState state) {
-		super(state,PlayState.BOARD_WIDTH/2, state.paddle.getY() + Paddle.PADDLE_HEIGHT + RADIUS);
+		super(state, state.paddle.getX(), state.paddle.getY() + Paddle.PADDLE_HEIGHT + RADIUS);
 		this.speed = state.bricks.size() > BLOCKS_FOR_BOOST? DEFAULT_SPEED : BOOST_SPEED;
+		createBody();
+	}
 
+	@Override
+	public void render(ShapeRenderer sr) {
+		sr.begin(ShapeType.Filled);
+		sr.setColor(BALL_COLOR);
+		sr.circle(pos.x * PlayState.PIXEL_PER_METER,
+				pos.y * PlayState.PIXEL_PER_METER,
+				RADIUS * PlayState.PIXEL_PER_METER);
+		sr.end();
+	}
+
+	@Override
+	public void update(float dt) {
+		if (isStuck || deleted) {
+			if (!deleted && Gdx.input.justTouched()) {
+				launch();
+			} else {
+				return;
+			}
+		}
+		if (touchedPaddle) {
+			paddleCollision();
+			touchedPaddle = false;
+		}
+
+		if (getY() + RADIUS < 0) {
+			deleted = true;
+		}
+
+		body.setLinearVelocity(body.getLinearVelocity().nor().scl(speed));
+	}
+
+	@Override
+	public Body getBody() {
+		return body;
+	}
+
+	@Override
+	public void createBody() {
 		BodyDef ballBody = new BodyDef();
 		ballBody.type = BodyDef.BodyType.DynamicBody;
 		ballBody.position.set(pos);
@@ -52,83 +92,22 @@ public class Ball extends Entity implements PhysicsBody {
 	}
 
 	@Override
-	public void render(ShapeRenderer sr) {
+	public void beginContact(Entity contacted) {
-		sr.begin(ShapeType.Filled);
+		if (contacted instanceof Shield) {
-		sr.setColor(BALL_COLOR);
+			contacted.delete();
-		sr.circle(pos.x * PlayState.PIXEL_PER_METER,
+		}
-				pos.y * PlayState.PIXEL_PER_METER,
+
-				RADIUS * PlayState.PIXEL_PER_METER);
+		if (contacted instanceof Paddle && !isStuck) {
-		sr.end();
+			touchedPaddle = true;
+		}
 	}
 
 	@Override
-	public void update(float dt) {
+	public void endContact(Entity contacted) {
-		if (isStuck || isDead) {
-			if (!isDead && Gdx.input.justTouched()) {
-				launch();
-			} else {
-				return;
-			}
-		}
-
-//		Vector2 new_pos = pos.cpy().add(direction.cpy().scl(speed * dt));
-//
-//		boolean brickCollision = false;
-//		Iterator<Brick> brickIterator = state.bricks.iterator();
-//		while (!brickCollision && brickIterator.hasNext()) {
-//			Brick brick = brickIterator.next();
-//			Vector2[] vertices = brick.getVertices();
-//			for(int i = 0; i < vertices.length; i++) {
-//				Vector2 v1 = vertices[i];
-//				Vector2 v2 = vertices[i+1 < vertices.length? i+1 : 0];
-//				Vector2 segment = v2.cpy().sub(v1);
-//				Vector2 nearest = Utils.nearestPoint(v1.cpy(), segment, new_pos.cpy());
-//
-//				if (nearest.dst(new_pos.x, new_pos.y) <= RADIUS) {
-//					if (brick.hit()) {
-//						brickIterator.remove();
-//					}
-//					Utils.reflect(direction, segment.nor());
-//					brickCollision = true;
-//					break;
-//				}
-//			}
-//		}
-//
-//		if (new_pos.x + RADIUS > BrickBuster.BOARD_WIDTH || new_pos.x - RADIUS < 0) {
-//			Utils.reflect(direction, Utils.VERTICAL_EDGE);
-//		} else if (new_pos.y + RADIUS > BrickBuster.BOARD_HEIGHT) {
-//			Utils.reflect(direction, Utils.HORIZONTAL_EDGE);
-//		} else if (state.getShieldCount() > 0
-//					&& new_pos.y - RADIUS < PlayState.SHIELD_HEIGHT * state.getShieldCount()) {
-//			Utils.reflect(direction, Utils.HORIZONTAL_EDGE);
-//			state.removeShield();
-//		} else if (new_pos.y + RADIUS < 0) {
-//			isDead = true;
-//			return;
-//		} else if (direction.y < 0 && new_pos.y <= state.paddle.getY() + Paddle.PADDLE_HEIGHT + RADIUS) {
-//			Pair<Vector2, Vector2> paddle = state.paddle.getTopEdge();
-//			Vector2 lineDir = paddle.getValue().sub(paddle.getKey());
-//			Vector2 nearest = Utils.nearestPoint(paddle.getKey().cpy(), lineDir, new_pos.cpy());
-//
-//			if (nearest.dst(new_pos.x, new_pos.y) <= RADIUS) {
-//				paddleCollision();
-//				if (state.paddle.isSticky()) {
-//					return;
-//				}
-//			}
-//		}
-//
-//		pos.add(direction.cpy().scl(speed * dt));
-	}
-
-	@Override
-	public Body getBody() {
-		return body;
 	}
 
 	public Vector2 paddleReflectAngle() {
-		int trim = (int) (state.paddle.getWidth() * 0.10);
+		float trim = state.paddle.getWidth() * 0.10f;
 		float rel = MathUtils.clamp((pos.x - state.paddle.getX()) + (state.paddle.getWidth()/2),
 				trim, state.paddle.getWidth()-trim);
 		float newAngle = MathUtils.PI - (MathUtils.PI * (rel / state.paddle.getWidth()));
@@ -136,6 +115,7 @@ public class Ball extends Entity implements PhysicsBody {
 	}
 
 	public void launch() {
+		Vector2 direction;
 		if (state.paddle.isSticky()) {
 			direction = paddleReflectAngle();
 		} else {
@@ -144,20 +124,34 @@ public class Ball extends Entity implements PhysicsBody {
 			direction = new Vector2(MathUtils.cos(angle), MathUtils.sin(angle));
 
 		}
-		//body.applyForceToCenter(new Vector2(0,Float.MAX_VALUE/2), true);
+		body.setLinearVelocity(direction.scl(speed));
-		//body.setLinearVelocity(new Vector2(0,10000000));
-		body.setLinearVelocity(direction.cpy().scl(speed));
-		body.setBullet(true);
 		isStuck = false;
 	}
 
 	public void paddleCollision() {
 		if (state.paddle.isSticky()) {
 			isStuck = true;
-			pos.y = state.paddle.getY() + Paddle.PADDLE_HEIGHT + RADIUS;
+			body.setLinearVelocity(new Vector2());
+			setY(state.paddle.getY() + Paddle.PADDLE_HEIGHT + RADIUS);
 			return;
 		}
-		direction = paddleReflectAngle();
+		body.setLinearVelocity(paddleReflectAngle().scl(speed));
+	}
+
+	@Override
+	public void setX(float x) {
+		super.setX(x);
+		Vector2 bodyPos = body.getPosition();
+		bodyPos.x = x;
+		body.setTransform(bodyPos, 0);
+	}
+
+	@Override
+	public void setY(float y) {
+		super.setY(y);
+		Vector2 bodyPos = body.getPosition();
+		bodyPos.y = y;
+		body.setTransform(bodyPos, 0);
 	}
 
 	public void setSpeed(float speed) {
@@ -168,15 +162,4 @@ public class Ball extends Entity implements PhysicsBody {
 		return isStuck;
 	}
 
-	public boolean isDead() {
-		return isDead;
-	}
-
-	public void setDirection(Vector2 direction) {
-		this.direction = direction;
-	}
-
-	public void setStuck(boolean stuck) {
-		isStuck = stuck;
-	}
 }

core/src/com/me/brickbuster/entity/Brick.java

@@ -9,10 +9,11 @@ import com.badlogic.gdx.physics.box2d.BodyDef;
 import com.badlogic.gdx.physics.box2d.FixtureDef;
 import com.badlogic.gdx.physics.box2d.PolygonShape;
 import com.me.brickbuster.entity.powerup.PowerUpType;
+import com.me.brickbuster.physics.CollisionListener;
 import com.me.brickbuster.physics.PhysicsBody;
 import com.me.brickbuster.state.PlayState;
 
-public class Brick extends Entity implements PhysicsBody {
+public class Brick extends Entity implements PhysicsBody, CollisionListener {
 
 	public static final Color DEFAULT_COLOR = Color.FOREST;
 	public static final float BRICK_WIDTH = 5f;
@@ -21,9 +22,8 @@ public class Brick extends Entity implements PhysicsBody {
 	private PowerUpType powerUpType;
 	private Color color;
 
-	private Vector2[] vertices;
-
 	private Body body;
+	private boolean hitByBall = false;
 
 	public Brick(PlayState state, PowerUpType powerUpType, float x, float y) {
 		this(state, powerUpType, true, x, y);
@@ -37,13 +37,35 @@ public class Brick extends Entity implements PhysicsBody {
 		super(state, x, y);
 		this.powerUpType = powerUpType;
 		this.color = powerUpType != null && !hidePowerUp? powerUpType.getColor() : color;
-		this.vertices = new Vector2[] {
+		createBody();
-			new Vector2(x, y),
+	}
-			new Vector2(x + BRICK_WIDTH, y),
-			new Vector2(x + BRICK_WIDTH, y + BRICK_HEIGHT),
-			new Vector2(x, y + BRICK_HEIGHT)
-		};
 
+	@Override
+	public void render(ShapeRenderer sr) {
+		sr.begin(ShapeType.Filled);
+		sr.setColor(color);
+		sr.rect(getX() * PlayState.PIXEL_PER_METER,
+				getY() * PlayState.PIXEL_PER_METER,
+				BRICK_WIDTH * PlayState.PIXEL_PER_METER,
+				BRICK_HEIGHT * PlayState.PIXEL_PER_METER);
+		sr.end();
+	}
+
+	@Override
+	public void update(float dt) {
+		if (hitByBall) {
+			hit();
+			hitByBall = false;
+		}
+	}
+
+	@Override
+	public Body getBody() {
+		return body;
+	}
+
+	@Override
+	public void createBody() {
 		BodyDef brickBody = new BodyDef();
 		brickBody.type = BodyDef.BodyType.StaticBody;
 		brickBody.position.set(pos.cpy());
@@ -64,23 +86,14 @@ public class Brick extends Entity implements PhysicsBody {
 	}
 
 	@Override
-	public void render(ShapeRenderer sr) {
+	public void beginContact(Entity contacted) {
-		sr.begin(ShapeType.Filled);
+		if (contacted instanceof Ball) {
-		sr.setColor(color);
+			hitByBall = true;
-		sr.rect(getX()*PlayState.PIXEL_PER_METER,
+		}
-				getY()*PlayState.PIXEL_PER_METER,
-				BRICK_WIDTH*PlayState.PIXEL_PER_METER,
-				BRICK_HEIGHT*PlayState.PIXEL_PER_METER);
-		sr.end();
 	}
 
 	@Override
-	public void update(float dt) {
+	public void endContact(Entity contacted) {
-	}
-
-	@Override
-	public Body getBody() {
-		return body;
 	}
 
 	public boolean hit() {
@@ -93,11 +106,9 @@ public class Brick extends Entity implements PhysicsBody {
 		if (powerUpType != null) {
 			state.powerUps.add(powerUpType.createInstance(state, this));
 		}
+
+		deleted = true;
 		return true;
 	}
 
-	public Vector2[] getVertices() {
-		return vertices;
-	}
-
 }

core/src/com/me/brickbuster/entity/Entity.java

@@ -8,6 +8,7 @@ public abstract class Entity {
 
 	protected PlayState state;
 	protected Vector2 pos;
+	protected boolean deleted = false;
 
 	public Entity(PlayState state, Vector2 pos) {
 		this(state, pos.x, pos.y);
@@ -46,4 +47,12 @@ public abstract class Entity {
 		pos.y = y;
 	}
 
+	public void delete() {
+		this.deleted = true;
+	}
+
+	public boolean isDeleted() {
+		return deleted;
+	}
+
 }

core/src/com/me/brickbuster/entity/Paddle.java

@@ -10,6 +10,7 @@ import com.badlogic.gdx.physics.box2d.Body;
 import com.badlogic.gdx.physics.box2d.BodyDef;
 import com.badlogic.gdx.physics.box2d.EdgeShape;
 import com.badlogic.gdx.physics.box2d.FixtureDef;
+import com.me.brickbuster.physics.CollisionListener;
 import com.me.brickbuster.physics.PhysicsBody;
 import com.me.brickbuster.state.PlayState;
 import net.dermetfan.utils.Pair;
@@ -31,24 +32,7 @@ public class Paddle extends Entity implements PhysicsBody {
 
 	public Paddle(PlayState brickBuster) {
 		super(brickBuster, PlayState.BOARD_WIDTH/2, PADDLE_Y);
-
+		createBody();
-		BodyDef paddleBody = new BodyDef();
-		paddleBody.type = BodyDef.BodyType.KinematicBody;
-		paddleBody.position.set(pos);
-
-		EdgeShape paddleShape = new EdgeShape();
-		paddleShape.set(new Vector2(-DEFAULT_WIDTH/2,PADDLE_HEIGHT),
-				new Vector2(DEFAULT_WIDTH/2, PADDLE_HEIGHT));
-
-		FixtureDef paddleFixture = new FixtureDef();
-		paddleFixture.shape = paddleShape;
-		paddleFixture.isSensor = true;
-
-		body = state.world.createBody(paddleBody);
-		body.createFixture(paddleFixture);
-		body.setUserData(this);
-
-		paddleShape.dispose();
 	}
 
 	@Override
@@ -69,7 +53,7 @@ public class Paddle extends Entity implements PhysicsBody {
 				setX(width/2);
 				return;
 			}
-			pos.x = pos.x - PADDLE_SPEED * dt;
+			setX(pos.x - PADDLE_SPEED * dt);
 
 			for (Ball ball : state.balls) {
 				if (ball.isStuck()) {
@@ -82,7 +66,7 @@ public class Paddle extends Entity implements PhysicsBody {
 				setX(PlayState.BOARD_WIDTH - width/2);
 				return;
 			}
-			pos.x = pos.x + PADDLE_SPEED * dt;
+			setX(pos.x + PADDLE_SPEED * dt);
 
 			for (Ball ball : state.balls) {
 				if (ball.isStuck()) {
@@ -92,16 +76,46 @@ public class Paddle extends Entity implements PhysicsBody {
 		}
 	}
 
+	@Override
+	public void createBody() {
+		BodyDef paddleBody = new BodyDef();
+		paddleBody.type = BodyDef.BodyType.KinematicBody;
+		paddleBody.position.set(pos);
+
+		EdgeShape paddleShape = new EdgeShape();
+		paddleShape.set(new Vector2(-width/2, PADDLE_HEIGHT),
+				new Vector2(width/2, PADDLE_HEIGHT));
+
+		FixtureDef paddleFixture = new FixtureDef();
+		paddleFixture.shape = paddleShape;
+		//paddleFixture.isSensor = true;
+
+		body = state.world.createBody(paddleBody);
+		body.createFixture(paddleFixture);
+		body.setUserData(this);
+
+		paddleShape.dispose();
+	}
+
 	@Override
 	public Body getBody() {
 		return body;
 	}
 
-	public Pair<Vector2, Vector2> getTopEdge() {
+	@Override
-		return new Pair<Vector2, Vector2>(
+	public void setX(float x) {
-				new Vector2(pos.x - width/2, pos.y + PADDLE_HEIGHT),
+		super.setX(x);
-				new Vector2(pos.x + width/2, pos.y + PADDLE_HEIGHT)
+		Vector2 bodyPos = body.getPosition();
-		);
+		bodyPos.x = x;
+		body.setTransform(bodyPos, 0);
+	}
+
+	@Override
+	public void setY(float y) {
+		super.setY(y);
+		Vector2 bodyPos = body.getPosition();
+		bodyPos.y = y;
+		body.setTransform(bodyPos, 0);
 	}
 
 	public float getWidth() {
@@ -109,7 +123,12 @@ public class Paddle extends Entity implements PhysicsBody {
 	}
 
 	public void setWidth(float width) {
+		if (this.width == width) {
+			return;
+		}
+		state.world.destroyBody(body);
 		this.width = width;
+		createBody();
 	}
 
 	public boolean isSticky() {

core/src/com/me/brickbuster/entity/Shield.java

@@ -0,0 +1,67 @@
+package com.me.brickbuster.entity;
+
+import com.badlogic.gdx.graphics.Color;
+import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
+import com.badlogic.gdx.math.Vector2;
+import com.badlogic.gdx.physics.box2d.Body;
+import com.badlogic.gdx.physics.box2d.BodyDef;
+import com.badlogic.gdx.physics.box2d.FixtureDef;
+import com.badlogic.gdx.physics.box2d.PolygonShape;
+import com.me.brickbuster.entity.powerup.PowerUpType;
+import com.me.brickbuster.physics.PhysicsBody;
+import com.me.brickbuster.state.PlayState;
+
+public class Shield extends Entity implements PhysicsBody {
+
+	public static final float SHIELD_HEIGHT = 0.75f;
+
+	private Body body;
+
+	public Shield(PlayState state) {
+		super(state, 0, state.getShieldCount() * SHIELD_HEIGHT);
+		createBody();
+	}
+
+	@Override
+	public void render(ShapeRenderer sr) {
+		sr.begin(ShapeRenderer.ShapeType.Filled);
+		sr.setColor(PowerUpType.SHIELD.getColor());
+		sr.rect(0, pos.y * PlayState.PIXEL_PER_METER,
+				PlayState.BOARD_WIDTH * PlayState.PIXEL_PER_METER,
+				SHIELD_HEIGHT * PlayState.PIXEL_PER_METER);
+		sr.end();
+	}
+
+	@Override
+	public void update(float dt) {
+		if (deleted) {
+			state.removeShield(this);
+		}
+	}
+
+	@Override
+	public void createBody() {
+		BodyDef brickBody = new BodyDef();
+		brickBody.type = BodyDef.BodyType.StaticBody;
+		brickBody.position.set(pos.cpy());
+
+		PolygonShape brickShape = new PolygonShape();
+		brickShape.setAsBox(PlayState.BOARD_WIDTH/2, SHIELD_HEIGHT/2,
+				new Vector2(PlayState.BOARD_WIDTH/2,SHIELD_HEIGHT/2), 0);
+
+		FixtureDef brickFixture = new FixtureDef();
+		brickFixture.shape = brickShape;
+		brickFixture.friction = 0f;
+
+		body = state.world.createBody(brickBody);
+		body.createFixture(brickFixture);
+		body.setUserData(this);
+
+		brickShape.dispose();
+	}
+
+	@Override
+	public Body getBody() {
+		return body;
+	}
+}

core/src/com/me/brickbuster/entity/powerup/MultiBallPowerUp.java

@@ -4,6 +4,7 @@ import com.badlogic.gdx.graphics.Color;
 import com.badlogic.gdx.math.MathUtils;
 import com.badlogic.gdx.math.Vector2;
 import com.me.brickbuster.entity.Ball;
+import com.me.brickbuster.entity.Paddle;
 import com.me.brickbuster.state.PlayState;
 
 public class MultiBallPowerUp extends PowerUp {
@@ -19,10 +20,7 @@ public class MultiBallPowerUp extends PowerUp {
 	public void activate() {
 		for (int x = 0; x < 2; x++) {
 			Ball ball = new Ball(state);
-			ball.setPos(pos.cpy());
+			ball.launch();
-			float angle = MathUtils.random(MathUtils.PI*2);
-			ball.setDirection(new Vector2(MathUtils.cos(angle), MathUtils.sin(angle)));
-			ball.setStuck(false);
 			state.balls.add(ball);
 		}
 	}

core/src/com/me/brickbuster/entity/powerup/PowerUp.java

@@ -10,11 +10,13 @@ import com.badlogic.gdx.physics.box2d.CircleShape;
 import com.badlogic.gdx.physics.box2d.FixtureDef;
 import com.me.brickbuster.Utils;
 import com.me.brickbuster.entity.Entity;
+import com.me.brickbuster.entity.Paddle;
+import com.me.brickbuster.physics.CollisionListener;
 import com.me.brickbuster.physics.PhysicsBody;
 import com.me.brickbuster.state.PlayState;
 import net.dermetfan.utils.Pair;
 
-public abstract class PowerUp extends Entity implements PhysicsBody {
+public abstract class PowerUp extends Entity implements PhysicsBody, CollisionListener {
 
 	public static final float RADIUS = 1.2f;
 	public static final float FALL_SPEED = 15f;
@@ -27,7 +29,38 @@ public abstract class PowerUp extends Entity implements PhysicsBody {
 	public PowerUp(PlayState state, Vector2 pos, Color color) {
 		super(state, pos);
 		this.color = color;
+		createBody();
+	}
 
+	@Override
+	public void render(ShapeRenderer sr) {
+		sr.begin(ShapeType.Filled);
+		sr.setColor(color);
+		sr.circle(getX() * PlayState.PIXEL_PER_METER,
+				getY() * PlayState.PIXEL_PER_METER,
+				RADIUS * PlayState.PIXEL_PER_METER);
+		sr.end();
+	}
+
+	@Override
+	public void update(float dt) {
+		if (isCaught) {
+			activate();
+			delete();
+		}
+
+		if (getY() + RADIUS < 0) {
+			delete();
+		}
+	}
+
+	@Override
+	public Body getBody() {
+		return body;
+	}
+
+	@Override
+	public void createBody() {
 		BodyDef ballBody = new BodyDef();
 		ballBody.type = BodyDef.BodyType.DynamicBody;
 		ballBody.position.set(pos);
@@ -43,45 +76,21 @@ public abstract class PowerUp extends Entity implements PhysicsBody {
 		body.createFixture(ballFixture);
 		body.setUserData(this);
 
+		body.setLinearVelocity(0f, -FALL_SPEED);
+
 		ballShape.dispose();
 	}
 
 	@Override
-	public void render(ShapeRenderer sr) {
+	public void beginContact(Entity contacted) {
-		sr.begin(ShapeType.Filled);
+		if (contacted instanceof Paddle) {
-		sr.setColor(color);
-		sr.circle(getX() * PlayState.PIXEL_PER_METER,
-				getY() * PlayState.PIXEL_PER_METER,
-				RADIUS * PlayState.PIXEL_PER_METER);
-		sr.end();
-	}
-
-	@Override
-	public void update(float dt) {
-		setY(getY() - FALL_SPEED * dt);
-
-		Pair<Vector2, Vector2> paddle = state.paddle.getTopEdge();
-		Vector2 lineDir = paddle.getValue().sub(paddle.getKey());
-		Vector2 nearest = Utils.nearestPoint(paddle.getKey().cpy(), lineDir, getPos().cpy());
-
-		if (nearest.dst(getX(), getY()) <= RADIUS) {
-			activate();
-			isCaught = true;
-		}
-
-		if (getY() + RADIUS < 0) {
 			isCaught = true;
 		}
 	}
 
 	@Override
-	public Body getBody() {
+	public void endContact(Entity contacted) {}
-		return body;
-	}
 
 	public abstract void activate();
 
-	public boolean isCaught() {
-		return isCaught;
-	}
 }

core/src/com/me/brickbuster/physics/PhysicsBody.java

@@ -4,6 +4,8 @@ import com.badlogic.gdx.physics.box2d.Body;
 
 public interface PhysicsBody {
 
+	void createBody();
+
 	Body getBody();
 
 }

core/src/com/me/brickbuster/state/PlayState.java

@@ -2,18 +2,19 @@ package com.me.brickbuster.state;
 
 import com.badlogic.gdx.Gdx;
 import com.badlogic.gdx.graphics.Color;
-import com.badlogic.gdx.graphics.glutils.ShapeRenderer.ShapeType;
 import com.badlogic.gdx.math.MathUtils;
 import com.badlogic.gdx.math.Vector2;
 import com.badlogic.gdx.physics.box2d.*;
+import com.badlogic.gdx.utils.Array;
 import com.me.brickbuster.BrickBuster;
-import com.me.brickbuster.entity.Ball;
+import com.me.brickbuster.entity.*;
-import com.me.brickbuster.entity.Brick;
+import com.me.brickbuster.entity.powerup.PowerUp;
-import com.me.brickbuster.entity.Paddle;
+import com.me.brickbuster.entity.powerup.PowerUpType;
-import com.me.brickbuster.entity.powerup.*;
 import com.me.brickbuster.physics.Box2dContactListener;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
 
 public class PlayState extends State {
 
@@ -22,8 +23,6 @@ public class PlayState extends State {
 	public static final float BOARD_HEIGHT = 96f;
 	public static final float EDGE_PADDING = .125f;
 
-
-	public static final float SHIELD_HEIGHT = 0.75f;
 	public static final float POWERUP_CHANCE = 0.15f;
 
 	public static final int COLUMNS = 9;
@@ -39,14 +38,16 @@ public class PlayState extends State {
 			new Vector2(EDGE_PADDING, BrickBuster.BOARD_HEIGHT/PIXEL_PER_METER-EDGE_PADDING);
 
 	public World world;
+
 	public Body playArea;
+	public Array<Body> bodies;
 
 	public List<PowerUp> powerUps;
 	public Paddle paddle;
 	public List<Ball> balls;
 	public List<Brick> bricks;
+	public List<Shield> shields;
 
-	private int shieldCount = 0;
 	private float updateTime = 0f;
 
 	private final Box2DDebugRenderer debugRenderer;
@@ -64,7 +65,9 @@ public class PlayState extends State {
 
 		// define a playArea body with position set to 0
 		BodyDef playAreaDef = new BodyDef();
+		playAreaDef.type = BodyDef.BodyType.StaticBody;
 		playAreaDef.position.set(new Vector2());
+
 		EdgeShape screenEdge = new EdgeShape();
 
 		playArea = world.createBody(playAreaDef);
@@ -78,8 +81,8 @@ public class PlayState extends State {
 		screenEdge.set(upperLeftCorner, lowerLeftCorner);
 		playArea.createFixture(screenEdge, 0f);
 		// Bottom edge
-		screenEdge.set(lowerLeftCorner, lowerRightCorner);
+		//screenEdge.set(lowerLeftCorner, lowerRightCorner);
-		playArea.createFixture(screenEdge, 0f);
+		//playArea.createFixture(screenEdge, 0f);
 		screenEdge.dispose();
 
 		powerUps = new ArrayList<PowerUp>();
@@ -103,10 +106,21 @@ public class PlayState extends State {
 
 		balls = new ArrayList<Ball>();
 		balls.add(new Ball(this));
+
+		shields = new ArrayList<Shield>();
 	}
 
 	@Override
 	public void render() {
+		Array<Body> bodies = new Array<Body>();
+		world.getBodies(bodies);
+		for (Body b : bodies) {
+			Entity e = (Entity) b.getUserData();
+			if (e instanceof Ball || e instanceof PowerUp) {
+				e.setPos(b.getPosition());
+			}
+		}
+
 		long start = System.nanoTime();
 		for (Brick block : bricks) {
 			block.render(game.sr);
@@ -117,14 +131,12 @@ public class PlayState extends State {
 		for (Ball ball : balls) {
 			ball.render(game.sr);
 		}
+		for (Shield shield : shields) {
+			shield.render(game.sr);
+		}
 		paddle.render(game.sr);
 
-		if (getShieldCount() > 0) {
+		//debugRenderer.render(world, game.cam.combined.cpy().scl(PIXEL_PER_METER));
-			game.sr.begin(ShapeType.Filled);
-			game.sr.setColor(Color.SALMON);
-			game.sr.rect(0, 0, BrickBuster.BOARD_WIDTH, getShieldCount() * SHIELD_HEIGHT);
-			game.sr.end();
-		}
 		long renderTime = System.nanoTime() - start;
 
 		game.sb.begin();
@@ -132,22 +144,19 @@ public class PlayState extends State {
 		game.font.draw(game.sb, String.format("FPS: %d Update: %.2f ms Render: %.2f ms",
 				Gdx.graphics.getFramesPerSecond(), updateTime/1000000f, renderTime/1000000f), 10, BrickBuster.BOARD_HEIGHT-10);
 		game.sb.end();
-
-		debugRenderer.render(world, game.cam.combined.cpy().scl(PIXEL_PER_METER));
 	}
 
 	@Override
 	public void update(float dt) {
 		long start = System.nanoTime();
-		world.step(dt, 6, 2);
-
 		paddle.update(dt);
 
 		for (Iterator<Ball> it = balls.iterator(); it.hasNext();) {
 			Ball ball = it.next();
 			ball.update(dt);
-			if (ball.isDead()) {
+			if (ball.isDeleted()) {
 				it.remove();
+				world.destroyBody(ball.getBody());
 			}
 		}
 		if (balls.isEmpty()) {
@@ -157,15 +166,36 @@ public class PlayState extends State {
 		for (Iterator<PowerUp> it = powerUps.iterator(); it.hasNext();) {
 			PowerUp powerUp = it.next();
 			powerUp.update(dt);
-			if(powerUp.isCaught()) {
+			if(powerUp.isDeleted()) {
 				it.remove();
+				world.destroyBody(powerUp.getBody());
 			}
 		}
 
+		for (Iterator<Shield> it = shields.iterator(); it.hasNext();) {
+			Shield shield = it.next();
+			shield.update(dt);
+			if(shield.isDeleted()) {
+				it.remove();
+				world.destroyBody(shield.getBody());
+			}
+		}
+
+		for (Iterator<Brick> it = bricks.iterator(); it.hasNext();) {
+			Brick brick = it.next();
+			brick.update(dt);
+			if (brick.isDeleted()) {
+				it.remove();
+				world.destroyBody(brick.getBody());
+			}
+		}
 		if (bricks.isEmpty()) {
 			game.setScreen(new MenuState(game));
 			dispose();
+			return;
 		}
+
+		world.step(dt, 6, 2);
 		updateTime = System.nanoTime() - start;
 	}
 
@@ -173,6 +203,8 @@ public class PlayState extends State {
 	public void dispose() {
 		super.dispose();
 
+		world.dispose();
+
 		powerUps.clear();
 		powerUps = null;
 		balls.clear();
@@ -183,25 +215,25 @@ public class PlayState extends State {
 	}
 
 	public int getShieldCount() {
-		return shieldCount;
+		return shields.size();
 	}
 
 	public void addShield() {
-		shieldCount++;
+		Shield shield = new Shield(this);
-		paddle.setY(paddle.getY() + SHIELD_HEIGHT);
+		shields.add(shield);
+		paddle.setY(paddle.getY() + Shield.SHIELD_HEIGHT);
 		for (Ball ball : balls) {
 			if (ball.isStuck()) {
-				ball.setY(ball.getY() + SHIELD_HEIGHT);
+				ball.setY(ball.getY() + Shield.SHIELD_HEIGHT);
 			}
 		}
 	}
 
-	public void removeShield() {
+	public void removeShield(Shield shield) {
-		shieldCount--;
+		paddle.setY(paddle.getY() - Shield.SHIELD_HEIGHT);
-		paddle.setY(paddle.getY() - SHIELD_HEIGHT);
 		for (Ball ball : balls) {
 			if (ball.isStuck()) {
-				ball.setY(ball.getY() - SHIELD_HEIGHT);
+				ball.setY(ball.getY() - Shield.SHIELD_HEIGHT);
 			}
 		}
 	}