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Box2D (2/2)

Here is the Obstacle.java :

public class Obstacle {
    
    public Body body;
    protected BodyDef bodyDef;
    protected FixtureDef fixtureDef;
    protected PolygonShape polygonShape;
    public float posX, posY, width, height, angle;
    Camera camera;
    
    public Obstacle(World world, Camera camera, MapObject rectangleObject){        
        create(world, camera, rectangleObject);     
    }
    
    public void create(World world, Camera camera, MapObject rectangleObject){

        Rectangle rectangle = ((RectangleMapObject) rectangleObject).getRectangle();
            
        this.camera = camera;
        this.posX = (rectangle.x + rectangle.width/2) * GameConstants.MPP;
        this.posY = (rectangle.y + rectangle.height/2) * GameConstants.MPP;
        this.width = (rectangle.width/2) * GameConstants.MPP;
        this.height = (rectangle.height/2) * GameConstants.MPP;
        
        if(rectangleObject.getProperties().get("rotation") != null)
            this.angle = -Float.parseFloat(rectangleObject.getProperties().get("rotation").toString())*MathUtils.degreesToRadians;
        
        polygonShape = new PolygonShape();
        polygonShape.setAsBox(width, height);


        bodyDef = new BodyDef();
        bodyDef.position.set(new Vector2(posX, posY));
        bodyDef.type = getBodyType();
        body = world.createBody(bodyDef);
        
        fixtureDef = new FixtureDef();
        fixtureDef.shape = polygonShape;
        fixtureDef.density = (float)(GameConstants.DENSITY/(width * height));  
        fixtureDef.friction = 0.5f;  
        fixtureDef.restitution = 0.5f;
   
        body.createFixture(fixtureDef).setUserData("Obstacle");
        body.setUserData("Obstacle");
        
        if(rectangleObject.getProperties().get("rotation") != null){
            /*
             * To obtain x' et y' positions from x et y positions after a rotation of an angle A
             * around the origine (0, 0) :
             * x' = x*cos(A) - y*sin(A)
             * y' = x*sin(A) + y*cos(A)
             */
            float X = (float)(body.getPosition().x - width + width * Math.cos(angle) + height * Math.sin(angle));
            float Y = (float)(width * Math.sin(angle) + body.getPosition().y + height - height * Math.cos(angle));
            body.setTransform(X, Y, this.angle);
        }
        
        polygonShape.dispose();  
    }
    
    public float getWidth(){
        return width;
    }
    
    public float getHeight(){
        return height;
    }
    
    public float getX(){
        return posX;
    }
    
    public float getY(){
        return posY;
    }

    public void setX( float X){
        posX = X;
    }

    public void setY( float Y){
        posY = Y;
    }

    public void active(){     
    }

    public BodyType getBodyType(){
        return BodyType.StaticBody;
    }
}

The Obstacle classe takes a RectangleMapObject given by the TiledMapReader and create a body using the coordinates and the size of the RectangleMapObject. The Obstacle classe as been thought to be a extended to create other obstacles, with different properties (moving obstacle, light or heavy obstacles...).

You can see in my code something that ight look not usual : The density of the obstacle is expressed like this :

fixtureDef.density = (float)(GameConstants.DENSITY/(width * height)); The reason is that it will allow me to easily control the mass of every object later.

OK, now we converted the Tiled Map into bodies with Box2D, now it's the time to have fun !!