Re: [flexcoders] Flash/FLex gravity

2009-04-22 Thread Nate Beck 
Yup Josh is correct, creating a vector is the way to go...
The "slowing down" force you're talking about is friction (at least in
physics). If you're interested in this kind of stuff, I highly recommend
picking up a copy of Keith Peters book:

http://www.amazon.com/Foundation-Actionscript-3-0-Animation-Making/dp/1590597915/ref=sr_1_1?ie=UTF8&s=books&qid=1240464956&sr=8-1

Cheers,

On Wed, Apr 22, 2009 at 9:19 PM, Josh McDonald wrote:

>
>
> That sort of thing (a vector) is easy, once you've determined the direction
> in radians, and a speed. Let's call it pixels-per-frame, to make things
> simple. Note that this is typed in gmail, and will need tweaks!
>
> accuratePositionX = x;
> accuratePositionY = y;
>
> velocityX = Math.cos(direction) * initialVelocity;
> velocityY = Math.sin(direction) * initialVelocity;
>
> //Do every frame:
> function updatePosition():void
> {
> accuratePositionX += velocityX;
> accuratePositionY += velocityY;
>
> x = Math.round(accuratePositionX);
> y = Math.round(accuratePositionY);
>
> velocityX *= 0.9;
> velocityY *= 0.9;
>
> if (velocityX < 0.05 && velocityX < 0.05)
> stopTheAnimation();
> }
>
> Cheers,
> -Josh
>
> 2009/4/23 flexaustin 
>
>>
>>
>> Does anyone know of a tutorial on actionscript and gravity. Not like
>> dropping a ball, but like google maps where you drag an item and it keeps
>> going in that direction but slowing down. So gravity in all directions
>> something like a hockey puck.
>>
>> TIA
>>
>>
>
>
> --
> "Therefore, send not to know For whom the bell tolls. It tolls for thee."
>
> Josh 'G-Funk' McDonald
>   -  j...@joshmcdonald.info
>   -  http://twitter.com/sophistifunk
>   -  http://flex.joshmcdonald.info/
>
>  
>



-- 

Cheers,
Nate

http://blog.natebeck.net

Re: [flexcoders] Flash/FLex gravity

2009-04-22 Thread Josh McDonald 
That sort of thing (a vector) is easy, once you've determined the direction
in radians, and a speed. Let's call it pixels-per-frame, to make things
simple. Note that this is typed in gmail, and will need tweaks!

accuratePositionX = x;
accuratePositionY = y;

velocityX = Math.cos(direction) * initialVelocity;
velocityY = Math.sin(direction) * initialVelocity;

//Do every frame:
function updatePosition():void
{
accuratePositionX += velocityX;
accuratePositionY += velocityY;

x = Math.round(accuratePositionX);
y = Math.round(accuratePositionY);

velocityX *= 0.9;
velocityY *= 0.9;

if (velocityX < 0.05 && velocityX < 0.05)
stopTheAnimation();
}

Cheers,
-Josh

2009/4/23 flexaustin 

>
>
> Does anyone know of a tutorial on actionscript and gravity. Not like
> dropping a ball, but like google maps where you drag an item and it keeps
> going in that direction but slowing down. So gravity in all directions
> something like a hockey puck.
>
> TIA
>
>  
>



-- 
"Therefore, send not to know For whom the bell tolls. It tolls for thee."

Josh 'G-Funk' McDonald
  -  j...@joshmcdonald.info
  -  http://twitter.com/sophistifunk
  -  http://flex.joshmcdonald.info/

[flexcoders] Flash/FLex gravity

2009-04-22 Thread flexaustin 
Does anyone know of a tutorial on actionscript and gravity. Not like dropping a 
ball, but like google maps where you drag an item and it keeps going in that 
direction but slowing down. So gravity in all directions something like a 
hockey puck.

TIA