ViSP  2.8.0

Shows how to activates the ring light.

* $Id: ringLight.cpp 4056 2013-01-05 13:04:42Z fspindle $
* This file is part of the ViSP software.
* Copyright (C) 2005 - 2013 by INRIA. All rights reserved.
* This software is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* ("GPL") version 2 as published by the Free Software Foundation.
* See the file LICENSE.txt at the root directory of this source
* distribution for additional information about the GNU GPL.
* For using ViSP with software that can not be combined with the GNU
* GPL, please contact INRIA about acquiring a ViSP Professional
* Edition License.
* See for more information.
* This software was developed at:
* INRIA Rennes - Bretagne Atlantique
* Campus Universitaire de Beaulieu
* 35042 Rennes Cedex
* France
* If you have questions regarding the use of this file, please contact
* INRIA at
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* Description:
* Example of ring light control.
* Author:
* Fabien Spindler
#include <visp/vpConfig.h>
#include <visp/vpDebug.h>
#include <cmath> // std::fabs
#include <limits> // numeric_limits
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <visp/vpRingLight.h>
#include <visp/vpParseArgv.h>
#include <visp/vpTime.h>
// List of allowed command line options
#define GETOPTARGS "d:hn:ot:"
void usage(const char *name, const char *badparam, int nsec, double nmsec)
fprintf(stdout, "\n\
Send a pulse to activate the ring light or turn on the ring light \n\
during %d s.\n\
By default, that means without parameters, send a pulse which duration\n\
is fixed by the harware. To control the duration of the pulse, use \n\
\"-t <pulse width in ms>\" option. To turn on the light permanently, \n\
use \"-o -n <on duration in second>]\"\n \
%s [-o] [-n <on duration in second>] [-t <pulse width in ms>] [-h]\n\
", nsec, name);
fprintf(stdout, "\n\
OPTIONS: Default\n\
Turn the ring light on during %d s.\n\
If this option is not set, send a short pulse\n\
to activate the light.\n\
-t %%g : <pulse width in ms> %g\n\
Pulse width in milli-second.\n\
Send a pulse which duration is fixed by this parameter.\n\
Without this option, the pulse width is fixed by the \n\
-n %%d : <on duration in second> %d\n\
Time in second while the ring light is turned on.\n\
This option is to make into realtion with option \"-o\".\n\
Print the help.\n\n", nsec, nmsec, nsec);
if (badparam) {
fprintf(stderr, "ERROR: \n" );
fprintf(stderr, "\nBad parameter [%s]\n", badparam);
bool getOptions(int argc, const char **argv, bool &on, int &nsec, double &nmsec)
const char *optarg;
int c;
while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg)) > 1) {
switch (c) {
case 'n': nsec = atoi(optarg); break;
case 'o': on = true; break;
case 't': nmsec = atof(optarg); break;
case 'h': usage(argv[0], NULL, nsec, nmsec); return false; break;
usage(argv[0], optarg, nsec, nmsec); return false; break;
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], NULL, nsec, nmsec);
std::cerr << "ERROR: " << std::endl;
std::cerr << " Bad argument " << optarg << std::endl << std::endl;
return false;
return true;
main(int argc, const char **argv)
bool on = false;
int nsec = 5; // Time while the ring light is turned on
double nmsec = 0; // Pulse duration
// Read the command line options
if (getOptions(argc, argv, on, nsec, nmsec) == false) {
exit (-1);
try {
vpRingLight light;
//if (nmsec == 0.)
if (std::fabs(nmsec) <= std::numeric_limits<double>::epsilon())
if (on) {
printf("Turn on ring light\n");
light.on(); // Turn the ring light on
vpTime::wait(nsec * 1000); // Wait 5 s; // and then turn the ring light off
else {
printf("Send a pulse to activate the ring light\n");
switch(e.getCode()) {
printf("Can't open the parallel port to access to the ring light device\n");
printf("Can't close the parallel port\n");
catch(...) {
printf("An error occurs...\n");
return 0;
vpTRACE("Sorry, for the moment, vpRingLight class works only on unix...");
return 0;