#! /usr/bin/gawk -f
# Last edited on 2013-01-07 10:32:00 by stolfilocal

# Client must define {nx,ny} = size of each block, {nd} = num of blocks

BEGIN{
  cx = int((nx-1)/2);
  cy = int((ny-1)/2);
  maxval = 65535;
  lo = int(maxval/4);
  hi = maxval - lo;
  printf "P2\n";
  printf "%d %d\n", nx, nd*ny;
  printf "%d\n", maxval;
  for (k = 0; k < nd; k++)
    { 
      for (y = 0; y < ny; y++)
        {
          for (x = 0; x < nx; x++)
            {
                printf " %d", ((x == cx+k) && (y == cy) ? hi : lo);
            }
          printf "\n";
        }
    }
  fflush("/dev/stdout");
}