Undefined reference to fp_init() Using fprint in Qt

I am trying to use the libfprint in my Qt application

#include <QtGui/QApplication>
#include "mainwindow.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <libfprint/fprint.h>    

int main(int argc, char *argv[])
{

    int r = 1;
    struct fp_dscv_dev *ddev;
    struct fp_dscv_dev **discovered_devs;
    struct fp_dev *dev;
    struct fp_print_data *data;

    r = fp_init();

    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

Compiling throws this error

/concept/main.cpp:31: undefined reference to `fp_init()'

I have been battling w开发者_StackOverflowith this for a while now. Any idea what I can do to get past this point? Thanks in advance!

---

It's a problem with your linker - it cannot find necessary libraries. Did you pass necessary linker switches (something like -lfoo) instructing it to link with library you are trying to use?