this is in java, drawing on a canvas inside of a jframe

Coding an asteroids game here. The problem is with the asteroids currently. they function normally until they hit a boundary of the drawing area. At this point they tend to stick to the boundary and move along it or suddenly stopping. I've looked at the positions of the asteroids, and they are not changing as they should be when the asteroid gets stuck. Also, they do not get stuck on the right and bottom borders, where the drawing surface does not quite meet the edge of the jframe for some reason. I'm not putting up any code atm, just checking to see if i can get any quick answers, i'll give code when there does not seem to be an easy solution.

Note: the player controlled ship moves around perfectly fine, not attaching to any walls or anything weird when it moves fast, but when the ship is moving slowly it gets stuck to the wall.

I've racked my brains and cannot come up with a solution

Going to make a video of this I think.

Are the asteroids supposed to wrap around when they hit a boundary? This doesn't sound like a graphics problem to me. Please post some code or provide more details if you expect to get any help.

http://www.youtube.com/watch?v=UsUKEtO_LIY
Here is a video of the problem. See how the asteroids attach themselves to the top and left sides.

For now the asteroids arn't supposed to wrap around, just move offscreen then despawn. This is working allright, if only the asteroids would make it offscreen.



This is the code setting up the jframe and drawing canvas. The asteroids are moving normally everywhere else so I'm thinking everything concerning their velocities and moving is ok. The size i'm working with is 800x600. Is there anything that causes (x,y) co-ordinates to snap to 0?

Let me know if you want any other code.

EDIT: Going to try turning the (x, y) co-ords into doubles.

This post has been edited by jyth: 7 Jul, 2009 - 10:30 AM

Keep in mind that a pixel is essentially indivisible. I'm pretty sure Java2D only deals with pixels so your (x, y) coords should be integers (ie. you can't have a half pixel).

Could you please post the code where you are updating the asteroid positions, doing collision checking, etc. I'm guessing the problem is there.

There are no collisions yet. The positions are updated by just adding the velocity on, this addition (for the asteroids) is usually less than one.

Turning the position values into doubles has seemed to work. When rendering I round off, but now I can accuratly add the velocities.