# Bounce Ball off Wall - Change Direction
**URL:** https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355
**Category:** flash
**Created:** [April 14, 2002, 6:35pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355 "2002-04-14T18:35:19Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 14, 2002, 6:35pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/1 "2002-04-14T18:35:19Z")
Hi,
This will be an easy one for you experts out there. I just want to have a ball randomly float through the movie & realize when it hits the wall of the movie & change directions. The moving part is no problem. I just need the logic for when the ball encounters the wall. Any help would be greatly appreciated,
Tim
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 14, 2002, 7:52pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/2 "2002-04-14T19:52:38Z")
when it hits the wall, all you want to do is reverse its x and y direction…
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 14, 2002, 7:53pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/3 "2002-04-14T19:53:16Z")
let’s say your movie is 400x400 and the ball is 20x20…
onClipEvent(load){
nXmov=(Math.random()_9)-4;
nYmov=(Math.random()9)-4;
}
onClipEvent(enterFrame){
if(\_x\<10){
\_x=10;
nXmov=-1;
} else if (\_x\>390){
\_x=390;
nXmov_=-1;
}
if(\_y\<10){
\_y=10;
nYmov\*=-1;
} else if (\_y\>390){
\_y=390;
nYmov\*=-1;
}
\_x+=nXmov;
\_y+=nYmov;
}
🙂
jeremy
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 14, 2002, 8:36pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/4 "2002-04-14T20:36:41Z")
I just hate your nXmov and sValStringStart variables :lol:
pom 0]
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 14, 2002, 8:41pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/5 "2002-04-14T20:41:01Z")
i love using variables like that. So much cleaner and easier to understand, but they can seem confusing if you don’t know what to look for.
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### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 14, 2002, 10:02pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/6 "2002-04-14T22:02:36Z")
You guys are the best.
Thank you so much.
Going to try it now . . .
Thanks again,
Tim
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 15, 2002, 7:04pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/7 "2002-04-15T19:04:41Z")
Ok, the code below works great & I think I understand it. I’m new to the game so bear with me. Anyone want to take a crack @ commenting this for me. Please don’t be afraid to over explain. Thanks again. It’s much appreciated,
Tim
let’s say your movie is 400x400 and the ball is 20x20…
onClipEvent(load){
nXmov=(Math.random()_9)-4;
nYmov=(Math.random()9)-4;
}
onClipEvent(enterFrame){
if(\_x\<10){
\_x=10;
nXmov=-1;
} else if (\_x\>390){
\_x=390;
nXmov_=-1;
}
if(\_y\<10){
\_y=10;
nYmov\*=-1;
} else if (\_y\>390){
\_y=390;
nYmov\*=-1;
}
\_x+=nXmov;
\_y+=nYmov;
}
jeremy
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 15, 2002, 7:36pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/8 "2002-04-15T19:36:30Z")
onClipEvent(load){
// set the speed for this movie clip.
nXmov=(Math.random()_9)-4;
nYmov=(Math.random()9)-4;
}
onClipEvent(enterFrame){
if(\_x\<10){
// if this clip is ‘out of bounds’ on the \_x axis place it ‘in bounds’ and reverse it’s direction on the \_x axis.
\_x=10;
nXmov=-1;
} else if (\_x\>390){
\_x=390;
nXmov_=-1;
}
if(\_y\<10){
// if this clip is ‘out of bounds’ on the \_y axis place it ‘in bounds’ and reverse it’s direction on the \_y axis.
\_y=10;
nYmov\*=-1;
} else if (\_y\>390){
\_y=390;
nYmov\*=-1;
}
// move this clip.
\_x+=nXmov;
\_y+=nYmov;
}
🙂
jeremy
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### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 17, 2002, 3:01pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/9 "2002-04-17T15:01:28Z")
Jeremy,
Wanted to thank you for the comments.
Much appreciated. Sorry for being such a dummy.
New to the game.
Tim
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 17, 2002, 4:12pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/10 "2002-04-17T16:12:47Z")
not a problem, we’ve all been there before!
🙂
jeremy
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [April 17, 2002, 4:40pm UTC](https://forum.kirupa.com/t/bounce-ball-off-wall-change-direction/2355/11 "2002-04-17T16:40:53Z")
ha! I don’t think you ever really started out slow with Flash. I think you were born (or produced rather) with the Macromedia symbol printed across your forehead. j/k…true…everyone has to start somewhere…