Function libeyelink_sys::eyelink_get_sample

pub unsafe extern "C" fn eyelink_get_sample(sample: *mut c_void) -> INT16

@ingroup messaging Gets an integer (unconverted) sample from end of queue, discards any events encountered.

@param sample Pointer to buffer (\c ISAMPLE or \c ALL_DATA type). @return \c 0 if no data. \c 1 if data retrieved.

\b Example:

\code

#include 

ISAMPLE   isample; // INTEGER SAMPLE DATA
int eye_used = 0;  // indicates which eye's data to display
float x, y;		   // gaze position
int i;

if(!eyelink_wait_for_block_start(100, 1, 0))
{
end_trial();
return TRIAL_ERROR;
}

eye_used = eyelink_eye_available();
switch(eye_used) // select eye, add annotation to EDF file
{
case RIGHT_EYE:
eyemsg_printf("EYE_USED 1 RIGHT");
break;
case BINOCULAR: // both eye's data present: use left eye only
eye_used = LEFT_EYE;
case LEFT_EYE:
eyemsg_printf("EYE_USED 0 LEFT");
break;
}

while(1)
{
i = eyelink_get_sample(&isample);
if(i)
{
if (x!=MISSING_DATA)
x = ((float) isample.gx[eye_used])/
((float) eyelink_position_prescaler());
else
x = (float) MISSING_DATA;

if (y!=MISSING_DATA)
y = ((float) isample.gy[eye_used])/
((float) eyelink_position_prescaler());
else
y = (float) MISSING_DATA;

eyemsg_printf("Sample: %ld %6.2f %6.2f", isample.time, x, y);
}

...
}
\endcode

\b Output:

\code
MSG	14839670 Sample: 14839666 539.20 372.60
MSG	14839670 Sample: 14839668 539.20 372.60
MSG	14839674 Sample: 14839670 539.20 372.60
MSG	14839674 Sample: 14839672 539.20 372.60
MSG	14839678 Sample: 14839674 547.90 367.60
MSG	14839678 Sample: 14839676 556.60 362.50
MSG	14839682 Sample: 14839678 565.30 357.40
MSG	14839682 Sample: 14839680 574.10 352.30
MSG	14839686 Sample: 14839682 582.80 347.20
MSG	14839686 Sample: 14839684 591.50 342.00
MSG	14839690 Sample: 14839686 600.30 336.80
MSG	14839690 Sample: 14839688 609.00 331.60
MSG	14839694 Sample: 14839690 617.80 326.40
MSG	14839694 Sample: 14839692 626.60 321.20
MSG	14839698 Sample: 14839694 635.30 315.90
MSG	14839698 Sample: 14839696 644.10 310.70
MSG	14839702 Sample: 14839698 652.90 305.40
MSG	14839702 Sample: 14839700 661.70 300.00
MSG	14839706 Sample: 14839702 670.50 294.70
MSG	14839706 Sample: 14839704 679.30 289.40
MSG	14839710 Sample: 14839706 688.10 284.00
MSG	14839710 Sample: 14839708 696.90 278.60
MSG	14839714 Sample: 14839710 705.80 273.20
MSG	14839714 Sample: 14839712 714.60 267.70
MSG	14839718 Sample: 14839714 723.40 262.30
MSG	14839718 Sample: 14839716 732.30 256.80
MSG	14839722 Sample: 14839718 741.20 251.30
MSG	14839722 Sample: 14839720 750.00 245.80
\endcode

\sa \c eyelink_get_float_data(), \c eyelink_get_last_data(), \c eyelink_get_next_data(), \c eyelink_newest_float_sample() and \c eyelink_newest_sample()