Whats wrong with this PerlinNoise function

Everytime i use this noise function it outputs the same value, no matter what the input is.

     static float noise2D(int x, int y) {
         
         int n = x + y * 57; 
         n = (n<<13) ^ n;
         return (float)( 1.0 - ( (n * (n * n * 15731 + 789221) + 1376312589) & (int)7) / 1073741824.0);         
         
     }
     
     static float smoothenNoise2D(int x, int y) { //smoothens surrounding points
         
         //starting from center, get corner points and add them together and divide by 16
         float corners = (noise2D(x-1,y-1) + noise2D(x + 1, y - 1) + noise2D(x + 1, y + 1) + noise2D( x- 1, y+1)) / 16;
         
         //starting from center, get center of each side
         float sides = (noise2D(x - 1, y) + noise2D(x + 1, y) + noise2D(x, y -1) + noise2D(x, y+1)) / 8;
         
         //get center point
         float center = noise2D(x,y) / 4;
         
         return corners + sides + center;
         
     }
     
     static float interpolateNoise2D(float x, float y) {
         
         int integerX = (int)x;
         int integerY = (int)y;
         
         float fractionalX = x - integerX;
         float fractionalY = y - integerY;
         
         float v1 = smoothenNoise2D(integerX, integerY);
         float v2 = smoothenNoise2D(integerX + 1, integerY);
         float v3 = smoothenNoise2D(integerX, integerY + 1);
         float v4 = smoothenNoise2D(integerX + 1, integerY + 1);
         
         float interpX = linearInterpolation(v1,v2,fractionalX);
         float interpY = linearInterpolation(v3,v4,fractionalY);
         
         return linearInterpolation(interpX, interpY, fractionalY);
         
     }
     
     public static float perlinNoise2D(float gx,float gy, int goctaves, float gpersistence) {
         
         x = gx;
         octaves = goctaves;
         persistence = gpersistence;    
         y = gy;
         
         float total = 0;
         
         int oct = octaves - 1;
         
         for(int i = 0; i < oct; i++) {
             
             float frequency = Mathf.Pow(2, i);
             float amplitude = Mathf.Pow (gpersistence,i);
             
             total += interpolateNoise2D(gx * frequency, gy * frequency) * amplitude;
             
         }
         
         return total;
         
     }