FIR Filter for complex float

Question

I have been using FIR filters for float variables, can I know how can I pass complex float variables ( complex float buf[1024] ) to the filter equations? I mean pointers to the variables of type complex float needs to be passed. I am reading complex float samples from the RTL SDR dongle and here is what I use for float samples:

void FIRFilter(float *x, int len) 
{     
 for (int k = 0; k < len; ++k) {
          float y = 0.0;
          int j = in_idx;
          bufff[in_idx] = x[k];
            
          for (int i = 0; i < n_tap; ++i) {
        if (j < 0)
          j += n_tap;
        y = y + m[i] * bufff[j--];  //mine a=coeff array
          }
          in_idx++;
          if (in_idx >= n_tap) {
        in_idx -= n_tap;
          }
          x[k] = (float)y;
        }
}