Hi @my5tery and thanks for your query. There is now available an early alpha release of the Stream Engine API for linux for you to try.

You can view the instructions for installation @ https://developer.tobii.com/consumer-eye-trackers/stream-engine/getting-started/

Hopefully this is exactly what you are looking for. Please let us know if we can be of any further assistance.

Hi @my5tery, the final part of the Stream Engine SDK process after installing the debian files is using the c++ libraries within the stream_engine_linux_3.0.4.6031.tar.gz file as included in the ZIP archive to create your first program.

Which IDE are you using for your programming? You will need to add the paths to the header and library files within your IDE to run your first C++ stream engine SDK application.

As a simple example, try compiling the following code after setting the paths:

#include <tobii/tobii.h>
#include <tobii/tobii_streams.h>
#include <stdio.h>
#include <assert.h>

void gaze_point_callback( tobii_gaze_point_t const* gaze_point, void* user_data )
{
    if( gaze_point->validity == TOBII_VALIDITY_VALID )
        printf( "Gaze point: %f, %f\n",
            gaze_point->position_xy[ 0 ],
            gaze_point->position_xy[ 1 ] );
}

static void url_receiver( char const* url, void* user_data )
{
    char* buffer = (char*)user_data;
    if( *buffer != '\0' ) return; // only keep first value

    if( strlen( url ) < 256 )
        strcpy( buffer, url );
}

int main()
{
    tobii_api_t* api;
    tobii_error_t error = tobii_api_create( &api, NULL, NULL );
    assert( error == TOBII_ERROR_NO_ERROR );

    char url[ 256 ] = { 0 };
    error = tobii_enumerate_local_device_urls( api, url_receiver, url );
    assert( error == TOBII_ERROR_NO_ERROR && *url != '\0' );

    tobii_device_t* device;
    error = tobii_device_create( api, url, &device );
    assert( error == TOBII_ERROR_NO_ERROR );

    error = tobii_gaze_point_subscribe( device, gaze_point_callback, 0 );
    assert( error == TOBII_ERROR_NO_ERROR );

    int is_running = 1000; // in this sample, exit after some iterations
    while( --is_running > 0 )
    {
        error = tobii_wait_for_callbacks( NULL, 1, &device );
        assert( error == TOBII_ERROR_NO_ERROR || error == TOBII_ERROR_TIMED_OUT );

        error = tobii_device_process_callbacks( device );
        assert( error == TOBII_ERROR_NO_ERROR );
    }

    error = tobii_gaze_point_unsubscribe( device );
    assert( error == TOBII_ERROR_NO_ERROR );

    error = tobii_device_destroy( device );
    assert( error == TOBII_ERROR_NO_ERROR );

    error = tobii_api_destroy( api );
    assert( error == TOBII_ERROR_NO_ERROR );
    return 0;
}

Please bear in mind you *will* need to calibrate otherwise the eye position data will not be reliable.

Try setting up your first program and let us know how you get on. Best Wishes.

Hi @my5tery, yes that’s right. The simple c++ code above is just to get the basic gaze co-ordinates and yes is a cpp file. I am afraid that the Stream Engine SDK is designed to work with an IDE so you will certainly need some kind of development environment to get started and thereafter hopefully can integrate with your RVIZ solution. Please let us know how you get on in this regard and we will try to help best we can.

Please bear in mind that as stated in the original Core SDK Stream Engine API homepage that the linux variant is still in early alpha and designed for advanced users so detailed support will be limited. Never the less, please try first compiling the above code and report back here on your progress. Best wishes.

Hi @my5tery, as described on Page 25 of tobii_stream_engine_api.pdf the position_xy is an array of two floats, for the horizontal (x) and vertical (y) screen coordinate of the gaze point and is called in the code above at this junction:

void gaze_point_callback( tobii_gaze_point_t const* gaze_point, void* user_data )
{
    if( gaze_point->validity == TOBII_VALIDITY_VALID )
        printf( "Gaze point: %f, %f\n",
            gaze_point->position_xy[ 0 ],
            gaze_point->position_xy[ 1 ] );
}

Hi @my5tery, could you please kindly clarify exactly which IDE and software versions you are working with and I will try to reproduce thanks.