link: http://www.nineb.com/lab/flash5/loopPicture/index.html
Flash version : 5
Graphic : bubbleball
Program : bubbleball

I always see a lot of people like to ask about loop picture. When I am newbies in flash, this work is a good workshop for doing and thinking. I think it is’n hard if you can calculate size of picture and know about how to get position (_x,_y) and lenght of object (_width, _height). From my experiece, I see that many one don’t care about smoothness of picture movement.

You will see that I build scroll bar for changing speed for test smoothness too. Why have to test?

If you use low speed for moving picture, you will not see anything wrong. But if you use high speed for moving picture, you will see that picture will move backward when it reset its position for making loop.

Easy technique for fix the problem is checking the next position of picture that it will move to. If picture will move over the reset point (point for moving picture to place at the begin position), you should reset reset position of it before.

Infact, you should use distances that picture can move over the reset point too and use it to calculate for new position after set the picture to place at the begin position.

Dowload it to learn basic movement in flash now.