Function libeyelink_sys::eyemsg_printf_ex

pub unsafe extern "C" fn eyemsg_printf_ex(
    exectime: UINT32, 
    fmt: *const c_char,
     ...
) -> INT16

@ingroup messaging This allows us to send messages to the Eyelink tracker to be logged into the data file with a time offset. Use it just like printf() to format the message text.

@param exectime time offset that reflects in the message's time stamp @param fmt printf format string @return \c 0 if OK, else error code.

\b Example:

@code

if(open_eyelink_connection(0) !=0)
return 0;
open_data_file("msgtest.edf");

eyemsg_printf("hello");
msec_delay(100);
eyemsg_printf_ex(-100,"hello1");
msec_delay(100);

eyemsg_printf_ex(100,"hello2");
msec_delay(100);
eyemsg_printf("hello3");
msec_delay(100);
close_data_file();
receive_data_file("",".",1);

@endcode

As you can see in the edf file data generated by the above code, both Message1 and Message2 has the same time stamp and message3 and message4 has the same time stamp.

@code
MSG     8004932 Message1
MSG     8004932 Message2
MSG     8005232 Message3
MSG     8005232 Message4
@endcode