get_random_pressure
tch_buf[index] = offset + get_random_pressure();
tch_buf[index - 1] = offset + get_random_pressure();
tch_buf[index + 1] = offset + get_random_pressure();
tch_buf[index - f->width] = offset + get_random_pressure();
tch_buf[index + f->width] = offset + get_random_pressure();
tch_buf[index - 1 - f->width] = offset + get_random_pressure();
tch_buf[index + 1 - f->width] = offset + get_random_pressure();
tch_buf[index - 1 + f->width] = offset + get_random_pressure();
tch_buf[index + 1 + f->width] = offset + get_random_pressure();
get_random_pressure();