gaze_data.c

#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include "tobii_research_eyetracker.h"
#include "tobii_research_streams.h"

#if _WIN32 || _WIN64
#include <windows.h>
static void sleep_ms(int time) {
    Sleep(time);
}
#else
#include <unistd.h>
static void sleep_ms(int time) {
    usleep(time * 1000);
}
#endif


void gaze_data_callback(TobiiResearchGazeData* gaze_data, void* user_data) {
    memcpy(user_data, gaze_data, sizeof(*gaze_data));
}

void gaze_data_example(TobiiResearchEyeTracker* eyetracker) {


    TobiiResearchGazeData gaze_data;
    char* serial_number;
    tobii_research_get_serial_number(eyetracker, &serial_number);

    printf("Subscribing to gaze data for eye tracker with serial number %s.\n", serial_number);

    tobii_research_free_string(serial_number);

    TobiiResearchStatus status = tobii_research_subscribe_to_gaze_data(eyetracker, gaze_data_callback, &gaze_data);

    if (status != TOBII_RESEARCH_STATUS_OK)
        return;

    /* Wait while some gaze data is collected. */
    sleep_ms(2000);

    status = tobii_research_unsubscribe_from_gaze_data(eyetracker, gaze_data_callback);
    printf("Unsubscribed from gaze data with status %i.\n", status);

    printf("Last received gaze package:\n");
    printf("System time stamp: %"  PRId64 "\n", gaze_data.system_time_stamp);
    printf("Device time stamp: %"  PRId64 "\n", gaze_data.device_time_stamp);
    printf("Left eye 2D gaze point on display area: (%f, %f)\n",
            gaze_data.left_eye.gaze_point.position_on_display_area.x,
            gaze_data.left_eye.gaze_point.position_on_display_area.y);
    printf("Right eye 3d gaze origin in user coordinates (%f, %f, %f)\n",
            gaze_data.right_eye.gaze_origin.position_in_user_coordinates.x,
            gaze_data.right_eye.gaze_origin.position_in_user_coordinates.y,
            gaze_data.right_eye.gaze_origin.position_in_user_coordinates.z);

    /* Wait while some gaze data is collected. */
    sleep_ms(2000);
}