Question

I currently have objects populating the screen randomly and bouncing around the stage. The problem is, some of the objects are getting stuck and bouncing back and forth rapidly between two points. How can I prevent this?

Here’s how I have the EnterFrame setup:

var ballT = e.target
ballT.x +=  ballT.vx;
ballT.y +=  ballT.vy;

if (ballT.x + ballT.width / 2 >= sWidth || ballT.x - ballT.width / 2 <= 0) {
    ballT.vx =  -  ballT.vx;
} else if (ballT.y + ballT.height / 2 >= sHeight || ballT.y - ballT.height / 2 <= 0) {
    ballT.vy =  -  ballT.vy;
}

Any ideas or any good reads worth checking out?

Answer 1

Most likely, your objects are going a bit “too much out of bounds”, so that when you turn them around, they don’t make it inside the bounds before you turn them around again. You may want to change the code to be a bit more clear on when to turn things around;

var ballT = e.target
ballT.x +=  ballT.vx;
ballT.y +=  ballT.vy;

// Outside to the right and heading right - turn around
if ( ballT.x + ballT.width / 2 >= sWidth && ballT.vx > 0 )
    ballT.vx = -ballT.vx;

// Outside to the left and heading left - turn around
if ( ballT.x - ballT.width / 2 <= 0 && ballT.vx < 0 )
    ballT.vx = -ballT.vx;

// Outside at the bottom and heading down - turn around
if ( ballT.y + ballT.height / 2 >= sHeight && ballT.vy > 0 )
    ballT.vy = -ballT.vy;

// Outside at the top and heading up - turn around
if ( ballT.y - ballT.height / 2 <= 0 && ballT.vy < 0 )
    ballT.vy = -ballT.vy;