Andengine how to gravity center

0
votes

My question about gravity of andengine, How I move my gravity to center of the screen ?

it's like this game http://jayisgames.com/games/krome/

I won't share a part of my code because I have just started now and I've added physicBox2D ,yet. I wonder that's logic thanks for reading please help me...

1
box2dandenginephysicsgravity

1 Answers

1
votes

In box2d there is no option to set the gravity to some direct point, you can just assing as gravity some vector so the gravity itself is rather about some direction.

Although you can simulate this by

  • setting world gravity to (0,0)

    World world = new World(new Vector2(0,0), true);

  • applying a force to body (or all bodies by iterating over them) in every render (game main loop iteration) equal to Gravitation. The example of setting gravity center to some centerBody:

    Body body, centerBody;

...

//in render method
float G = 1; //modifier of gravity value - you can make it bigger to have stronger gravity

float distance = body.getPosition().dst( centerBody.getPosition() ); 
float forceValue = G / (distance * distance);

Vector2 direction = centerBody.getPosition().sub( body.getPosition() ) );

body.applyForce( direction.mul( forceValue ), body.getWorldCenter() ); //the mul method is the same that scl in Libgdx I guess

If you want to apply gravity not to some centerBody but direct point just set new Vector2(0,0) instead of centerBody.getPosition