exposure.c

This example can be found in examples\c\exposure\exposure.c.

This example shows how to adjust exposure settings using the PST SDK. It shows how to change exposure settings based on frame rate and the available exposure range for a certain PST Tracker at a certain frame rate.

When compiling and running this example, please make sure that the required dependencies can be found by the executable (e.g. by copying the Redist directory into the build directory. When the PST SDK has been installed through the PST Software Suite installer the Redist folder can be found in the Development folder.).

 
#ifdef WIN32
#include <windows.h>
#else
#include <unistd.h>
#endif
 
/*
 * Define handler functions required to ensure a clean shutdown of the PST Tracker when the
 * application is terminated.
 */
 
static void Exithandler(int sig);
 
#ifdef WIN32
BOOL WINAPI ConsoleHandler(DWORD CEvent)
{
    Exithandler(CEvent);
    return TRUE;
}
#endif
 
/* End of handler functions */
 
#include "pstsdk_c.h"
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <signal.h>
 
/* Control variable for main loop */
static sig_atomic_t running = 1;
 
/* Number of data points to grab before application termination */
static const uint32_t numberOfSamplesToGrab = 1000;
 
/*
 * Implementation of a tracker callback function.
 * The OnTrackerData() callback function receives the data as soon as it becomes
 * available and prints the tracking target pose to the command line.
 */
void OnTrackerData(const PstTrackerData* tracker_data, EPstErrorStatus status)
{
    static uint32_t samplesGrabbed = 0;
    if (samplesGrabbed++ >= numberOfSamplesToGrab)
        running = 0;
 
    // Do something with the received data.
}
 
/*
* Implement the exit handler to shut-down the PST Tracker connection on application termination.
*/
static void Exithandler(int sig)
{
    pst_sdk_shutdown();
    running = 0;
}
 
// Print the last error message.
void PrintLastErrorMessage()
{
    char* last_error_message = NULL;
    EPstErrorStatus error_status = pst_alloc_and_get_last_error_message(&last_error_message);
    if (error_status != PST_ERROR_STATUS_OK)
    {
        last_error_message = "Failed to allocate memory error.";
    }
    printf("last error message: %s \n", last_error_message);
    pst_free(last_error_message);
}
 
// Check error status and shutdown tracker upon error.
void CheckErrorCode(EPstErrorStatus status)
{
    if (status != PST_ERROR_STATUS_OK)
    {
        PrintLastErrorMessage();
        pst_sdk_shutdown();
        exit(status);
    }
}
 
int main(int argc, char *argv[])
{
 
    // Register the exit handler with the application
#ifdef WIN32
    SetConsoleCtrlHandler((PHANDLER_ROUTINE)ConsoleHandler, TRUE);
#else
    signal(SIGTERM, Exithandler);
    signal(SIGKILL, Exithandler);
    signal(SIGQUIT, Exithandler);
    signal(SIGINT, Exithandler);
#endif
 
    PstTracker ctracker;
 
#ifdef WIN32
    // Create an instance of the Tracker object using the default configuration path and file names.
    CheckErrorCode(pst_tracker_init(&ctracker));
#else
    // On Linux, specify the type of grabber that needs to be used as the last parameter:
    // "basler_ace" for PST HD or "basler_dart" for PST Pico
    CheckErrorCode(pst_tracker_init4(&ctracker, "", "config.cfg", "models.db", argv[1]));
#endif
 
    char* version_string;
    CheckErrorCode(pst_tracker_alloc_and_get_version_info(&ctracker, &version_string));
    // Print version number of the tracker server being used.
    printf("Running PST Server version %s \n", version_string);
    pst_free(version_string);
 
    // Register the OnTrackerData callback function to the tracker server.
    CheckErrorCode(pst_tracker_add_tracker_data_callback(&ctracker, OnTrackerData));
 
    // Start the tracker server.
    CheckErrorCode(pst_tracker_start(&ctracker));
 
    // Perform a system check to see if the tracker server is running OK and print the result.
    printf("System check: %i \n\n", (int)pst_tracker_system_check(&ctracker));
    printf("***************************\n\n");
 
    // Set the frame rate to 30 Hz.
    CheckErrorCode(pst_tracker_set_framerate(&ctracker, 30.0));
 
    // Print the new frame rate to see if it was set correctly. Note that for PST HD and Pico
    // trackers the frame rate actually being set can differ from the value provided to pst_tracker_set_framerate().
    double fps;
    CheckErrorCode(pst_tracker_get_framerate(&ctracker, &fps));
    printf("Frame rate set to %f Hz\n", fps);
 
    // Query available exposure range for the current frame rate and try setting the maximum exposure value
    double min, max;
    CheckErrorCode(pst_tracker_get_exposure_range(&ctracker, &min, &max));
    printf("Exposure range: %f s - %f s\n", min, max);
    printf("Set exposure to %f \n", max);
    CheckErrorCode(pst_tracker_set_exposure(&ctracker, max));
    double exposure;
    CheckErrorCode(pst_tracker_get_exposure(&ctracker, &exposure));
    printf("Check new exposure: %f s\n\n", exposure);
    printf("***************************\n\n");
 
    // Increase frame rate and check exposure value. For PST HD and PST Pico trackers, maximum exposure
    // depends on frame rate. Exposure will be automatically decreased when necessary.
    printf("Set frame rate to 60 Hz\n");
    CheckErrorCode(pst_tracker_set_framerate(&ctracker, 60.0));
    CheckErrorCode(pst_tracker_get_framerate(&ctracker, &fps));
    printf("Frame rate set to %f Hz\n", fps);
    CheckErrorCode(pst_tracker_get_exposure(&ctracker, &exposure));
    printf("Check exposure: %f s\n", exposure);
 
    // Check new exposure range
    CheckErrorCode(pst_tracker_get_exposure_range(&ctracker, &min, &max));
    printf("New exposure range %f s - %f s\n\n", min, max);
    printf("***************************\n\n");
 
    // Set exposure half-way
    double exposureHalf = min + (max - min) / 2.0;
    printf("Set exposure half way: %f s\n", exposureHalf);
    CheckErrorCode(pst_tracker_set_exposure(&ctracker, exposureHalf));
    CheckErrorCode(pst_tracker_get_exposure(&ctracker, &exposure));
    printf("New exposure: %f s\n\n", exposure);
    printf("***************************\n\n");
 
    // Main loop, wait for auto-termination.
    while (running == 1)
    {
#ifdef WIN32
        Sleep(100);
#else
        usleep(100000);
#endif
    }
 
    // Make sure that the connection to the PST Tracker is shut down properly.
    pst_tracker_destroy(&ctracker);
 
    // Pause command line to see results.
    printf("Press enter to continue...\n");
    getchar();
 
    return 0;
}