Actionscript: Pseudo-Random Number creation with seeds - actionscript-3

Question

I am creating a function that returns a Perlin Noise Number in Flash.
For this function I must have a function that returns a random number from a static seed. Unfortunately the default Math.random in Actionscript can't do this..
I searched for a long time on the internet and I couldn't find a solution that fits my perlin-noise function.
I tried the following codes:
public static var seed:int = 602366;
public static function intNoise(x:int, y:int):Number {
var n:Number = seed * 16127 + (x + y * 57);
n = n % 602366;
seed = n | 0;
if (seed <= 0) seed = 1;
return (seed * 0.00000166) * 2 - 1;
}
This function does create a Random number, but the seed changes all the time so this doesn't work with perlin noise.
public static function intNoise(x:int, y:int):Number {
var n:Number = x + y * 57;
n = (n<<13) ^ n;
return ( 1 - ( (n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824.0);
}
I got this function from the Perlin Noise tutorial I followed: Perlin Noise, but it only seems to return 1.
How can I create a function that always returns the same Pseudo-Random number when called with the same seed?

Answer 1

I looked at the random number generator mentioned in the link and it looks like this:
function IntNoise(32-bit integer: x)
x = (x<<13) ^ x;
return ( 1.0 - ( (x * (x * x * 15731 + 789221) + 1376312589) & 7fffffff) / 1073741824.0);
end IntNoise function
I translated it thus:
package
{
import flash.display.*;
public class Main extends Sprite {
private var seeds:Array =
[ -1000, -999, -998, 7, 11, 13, 17, 999, 1000, 1001 ];
public function Main() {
for ( var i:int = 0; i < 10; i++ )
trace( intNoise( seeds[ i ] ) );
// Outputs: 1, 0, 0, -0.595146656036377, -0.1810436248779297,
// 0.8304634094238281, -0.9540863037109375, 0, 0, 1
}
// returns floating point numbers between -1.0 and 1.0
// returns 1 when x <= -1000 || x >= 1001 because b becomes 0
// otherwise performs nicely
public function
intNoise( x:Number ):Number {
x = ( uint( x << 13 ) ) ^ x;
var a:Number = ( x * x * x * 15731 + x * 789221 );
var b:Number = a & 0x7fffffff;
return 1.0 - b / 1073741824.0;
}
}
}