#include "rmannotes.sl"

displacement dispnoise7(float freq = 8, Km = .2, flatness = .2;)
{

  /* VARIABLES */

  float ss, tt;
  float fuzz = 0.5;
  float mag, layer_mag, surface_mag;
  float noi;
  float col, row;
  float width, cutoff, fade, f, turb, maxfreq = 25;
  point Nf, PP;

 /* NOISE */

  col = whichtile(s, freq);
  row = whichtile(t, freq);
  noi = noise(col * row);

  /* TURBULENCE */

  PP = transform("shader", P) * freq;

  width = filterwidth_point(PP);
  cutoff = clamp(0.5 / width, 0, maxfreq);

  turb = 1;
  for (f = 1.5; f < 0.5 * cutoff; f *= 2.3) 
    turb += abs(snoise(PP * f - noi)) / 3;
  fade = clamp(2 * (cutoff - f) / cutoff, 0, 1);
  turb += fade * abs(snoise(PP * f)) / f;

  /* CREATE FLAT AREAS */

  mag = pow(turb * noi, flatness);
  surface_mag = .5;

 
  /* OUTPUT */

  P += Km * mag * normalize(N);
  N = calculatenormal(P);
 
}