Finding a random point on a circle

[Fuzzy]

Bee Ant asked me how to do this, and we thought that everyone should know. So thank him if its useful to you.

First, pick a number from 0 to 359. Store it in a variable. I used i.

Next, use two variables to store floats. that is variable type real. Call them xr and yr for radius. Next you need an integer to store distance from center. I used d.
After these lines of code you can use xr and yr to add to an actor's x and y. This is good for special effects.

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i = rand(360);
xr = cos(degtorad(i))*d;
yr = sin(degtorad(i))*d;


visual demonstration here.

http://www.dreade.org/applets/circlerandom/

Thanks to DST for the hosting.

[Kalladdolf]

Thanks a bunch, this is way less complicated than the formula my brother-in-law once came up with!

[Fuzzy]

Thanks a bunch, this is way less complicated than the formula my brother-in-law once came up with!

You will find it develops holes when the radius gets big.

[Kalladdolf]

And if you use i as a float (or is that what you're already doing)?

[Fuzzy]

It doesnt matter if i is a float or an int.

[Bee-Ant]

WE thought that everyone should know

I didn't think about it...

[Kalladdolf]

Anyway... until now it's worked great so far.
Are those holes regular or irregular?

[Bee-Ant]

Whaddya mean with regular or irregular?
I used this code to make recharge effect.

[Fuzzy]

Anyway... until now it's worked great so far.
Are those holes regular or irregular?

Regular.

[Bee-Ant]

Btw fuz,do you know how to make formula that has the same function with "MoveTo" using angle and directional_velocity?

[Kalladdolf]

Anyway... until now it's worked great so far.
Are those holes regular or irregular?

Regular.

From that I would conclude that with a certain radius, normal angle values (like 1,2,3,4, 89, 134, 343) become too unspecific.
I think I might try a float variable with more precise numbers, maybe the holes'll get smaller.
EDIT:
@Bee-ant: You mean just the simple MoveTo function without avoid? I always used:

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angle = direction(x,y,destination.x,destination.y); directional_velocity = whatever;

And then some coordinates to stop the actor from moving once it's there.

[Bee-Ant]

What!!!
Ehm...thanks
Thats what i need...

[Kalladdolf]

You sure that wasn't sarcastic?

[Bee-Ant]

Huh?course not...

Hmmm,actualy i was thinking about direction,but just dont know the syntax yet...

Oh yah,do you have machinary sound such as motor,robot,laser,metal,etc?
Also some pic of futuristic machinary building or room?
Want them sooo much...well,i think i need to topic this.

[Kalladdolf]

Huh?course not...

Oh, right, yeah, it sounded to me like I defeated the purpose completely. Glad I didn't.