// Create foreground and background bitmaps of picture
// EyeLink graphics: blank display with box at center
// type: 0 = blank background, 1= blank fovea (mask), 2 = blurred background
static int create_image_bitmaps(int type)
{
target_foreground_color = RGB(0,0,0); // color of calibration target
target_background_color = RGB(128,128,128); // background for drift correction
set_calibration_colors(target_foreground_color, target_background_color); // tell EXPTSPPT the colors
clear_full_screen_window(target_background_color);
// NOTE: *** THE FOLLOWING TEXT SHOULD NOT APPEAR IN A REAL EXPERIMENT!!!! ****
get_new_font("Arial", 24, 1);
graphic_printf(target_foreground_color, -1, 1, SCRWIDTH/2, SCRHEIGHT/2, "Loading image...");
switch(type)
{
case 0: // blank background
fgbm = image_file_bitmap("images/sacrmeto.jpg", 0, SCRWIDTH,SCRHEIGHT,target_background_color);
bgbm = blank_bitmap(target_background_color);
break;
case 1: // blank fovea
fgbm = blank_bitmap(target_background_color);
bgbm = image_file_bitmap("images/sacrmeto.jpg", 0, SCRWIDTH,SCRHEIGHT,target_background_color);
break;
case 2: // normal and blurred bitmaps, stretched to fit display
fgbm = image_file_bitmap("images/sacrmeto.jpg", 0, SCRWIDTH,SCRHEIGHT,target_background_color);
bgbm = image_file_bitmap("images/sac_blur.jpg", 0, SCRWIDTH,SCRHEIGHT,target_background_color);
break;
}
eyecmd_printf("clear_screen 0"); // clear EyeLink display
eyecmd_printf("draw_box %d %d %d %d 15", // Box around fixation point
SCRWIDTH/2-16, SCRHEIGHT/2-16, SCRWIDTH/2+16, SCRHEIGHT/2+16);
if(!fgbm || !bgbm) // Check that both bitmaps exist.
{
eyemsg_printf("ERROR: could not load image");
alert_printf("ERROR: could not load an image file");
if(fgbm) DeleteObject(fgbm);
if(bgbm) DeleteObject(bgbm);
return SKIP_TRIAL;
}
return 0;
}
// Create foreground and background bitmaps of text
static int create_text_bitmaps(void)
{
RECT margins; // margins for text
margins.top = SCRHEIGHT/20; // set margin in about 1°
margins.left = SCRWIDTH/20;
margins.right = SCRWIDTH - SCRWIDTH/20;
margins.bottom = SCRHEIGHT - SCRHEIGHT/20;
target_foreground_color = RGB(0,0,0); // color of calibration target
target_background_color = RGB(255,255,255); // background for drift correction
set_calibration_colors(target_foreground_color, target_background_color); // tell EXPTSPPT the colors
get_new_font("Courier New", SCRHEIGHT/32, 1); // create a monospaced font
// Draw text and EyeLink graphics
fgbm = text_bitmap_segment(fg_text, RGB(0,0,0), RGB(255,255,255), margins, SCRHEIGHT/15, 0,
"text.ias", "segments", SV_NOREPLACE); // Create bitmap and its segmentation (if it does not exist)
// IAREA command is recorded for EyeLink Data Viewer analysis
// It creates a set of interest areas by reading the segment files
// Writes segmentation filename + path info
eyemsg_printf("!V IAREA FILE segments/text.ias");
// Draw text and EyeLink graphics for the background bitmap
bgbm = text_bitmap(bg_text, RGB(0,0,0), RGB(255,255,255), margins, SCRHEIGHT/15, 0);
if(!fgbm || !bgbm) // Check that both bitmaps exist.
{
eyemsg_printf("ERROR: could not load image");
alert_printf("ERROR: could not load an image file");
if(fgbm) DeleteObject(fgbm);
if(bgbm) DeleteObject(bgbm);
return SKIP_TRIAL;
}
return 0;
}
int app_main(char * trackerip, DISPLAYINFO * disp)
{
UINT16 i, j;
char our_file_name[260] = "TEST";
char verstr[50];
int eyelink_ver = 0;
int tracker_software_ver = 0;
if(trackerip)
set_eyelink_address(trackerip);
if(open_eyelink_connection(0)) return -1; /* abort if we can't open link */
set_offline_mode();
flush_getkey_queue(); /* initialize getkey() system */
eyelink_ver = eyelink_get_tracker_version(verstr);
if (eyelink_ver == 3)
tracker_software_ver = get_tracker_sw_version(verstr);
if(init_expt_graphics(NULL, disp))
goto shutdown; /* register window with EXPTSPPT */
window = SDL_GetVideoSurface();
get_display_information(&dispinfo); /* get window size, characteristics */
/*
NOTE: Camera display does not support 16-color modes
NOTE: Picture display examples don't work well with 256-color modes
However, all other sample programs should work well.
*/
if(dispinfo.palsize) /* 256-color modes: palettes not supported by this example */
alert_printf("This program is not optimized for 256-color displays");
i = SCRWIDTH/60; /* select best size for calibration target */
j = SCRWIDTH/300; /* and focal spot in target */
if(j < 2) j = 2;
set_target_size(i, j); /* tell DLL the size of target features */
/* color of calibration target */
SETCOLOR(target_foreground_color, 0,0,0);
/* background for calibration and drift correction */
SETCOLOR(target_background_color, 128,128,128);
/* tell EXPTSPPT the colors */
set_calibration_colors(&target_foreground_color, &target_background_color);
set_cal_sounds("", "", "");
set_dcorr_sounds("", "off", "off");
/* draw a title screen */
clear_full_screen_window(target_background_color); /* clear screen */
get_new_font("Times Roman", SCRHEIGHT/32, 1); /* select a font */
/* Draw text */
graphic_printf(window, target_foreground_color, CENTER, SCRWIDTH/2, 1*SCRHEIGHT/30,
"EyeLink Demonstration Experiment: Communicate with Listener");
graphic_printf(window, target_foreground_color, CENTER, SCRWIDTH/2, 2*SCRHEIGHT/30,
"Included with the Experiment Programming Kit for Windows");
graphic_printf(window, target_foreground_color, CENTER, SCRWIDTH/2, 3*SCRHEIGHT/30,
"All code is Copyright (c) 1997-2002 SR Research Ltd.");
graphic_printf(window, target_foreground_color, CENTER, SCRWIDTH/5, 4*SCRHEIGHT/30,
"Source code may be used as template for your experiments.");
SDL_Flip(window);
eyelink_set_name("comm_simple"); /* NEW: set our network name */
if(check_for_listener()) /* check for COMM_LISTENER application */
{
alert_printf("Could not communicate with COMM_LISTENER application.");
goto shutdown;
}
if(i==1) our_file_name[0] = 0; /* Cancelled: No file name */
if(our_file_name[0]) /* If file name set, open it */
{
if(!strstr(our_file_name, ".")) strcat(our_file_name, ".EDF"); /* add extension */
i = open_data_file(our_file_name); /* open file */
if(i!=0) /* check for error */
{
alert_printf("Cannot create EDF file '%s'", our_file_name);
goto shutdown;
}
/* add title to preamble */
eyecmd_printf("add_file_preamble_text 'RECORDED BY %s' ", program_name);
}
/*
SET UP TRACKER CONFIGURATION
NOTE: set contents before sending messages!
set EDF file contents
*/
if(eyelink_ver>=2)
{
eyecmd_printf("select_parser_configuration 0"); // 0 = standard sensitivity
if(eyelink_ver == 2) //turn off scenelink camera stuff
{
eyecmd_printf("scene_camera_gazemap = NO");
}
}
else
{
eyecmd_printf("saccade_velocity_threshold = 35");
eyecmd_printf("saccade_acceleration_threshold = 9500");
}
// NOTE: set contents before sending messages!
// set EDF file contents
eyecmd_printf("file_event_filter = LEFT,RIGHT,FIXATION,SACCADE,BLINK,MESSAGE,BUTTON");
eyecmd_printf("file_sample_data = LEFT,RIGHT,GAZE,AREA,GAZERES,STATUS%s",(tracker_software_ver>=4)?",HTARGET":"");
// set link data (used for gaze cursor)
eyecmd_printf("link_event_filter = LEFT,RIGHT,FIXATION,SACCADE,BLINK,BUTTON");
eyecmd_printf("link_sample_data = LEFT,RIGHT,GAZE,GAZERES,AREA,STATUS%s",(tracker_software_ver>=4)?",HTARGET":"");
/* NEW: Allow EyeLink I (v2.1+) to echo messages back to listener */
eyecmd_printf("link_nonrecord_events = BUTTONS, MESSAGES");
/* Program button #5 for use in drift correction */
eyecmd_printf("button_function 5 'accept_target_fixation'");
/* Now configure tracker for display resolution */
eyecmd_printf("screen_pixel_coords = %ld %ld %ld %ld", /* Set display resolution */
dispinfo.left, dispinfo.top, dispinfo.right, dispinfo.bottom);
eyecmd_printf("calibration_type = HV9"); /* Setup calibration type */
eyemsg_printf("DISPLAY_COORDS %ld %ld %ld %ld",/* Add resolution to EDF file */
dispinfo.left, dispinfo.top, dispinfo.right, dispinfo.bottom);
if(dispinfo.refresh>40)
eyemsg_printf("FRAMERATE %1.2f Hz.", dispinfo.refresh);
/* make sure we're still alive */
if(!eyelink_is_connected() || break_pressed()) goto end_expt;
/*
RUN THE EXPERIMENTAL TRIALS (code depends on type of experiment)
Calling run_trials() performs a calibration followed by trials
This is equivalent to one block of an experiment
It will return ABORT_EXPT if the program should exit
*/
i = run_trials();
end_expt: /* END: close, transfer EDF file */
set_offline_mode(); /* set offline mode so we can transfer file */
pump_delay(500); /* delay so tracker is ready */
eyecmd_printf("close_data_file"); /* close data file */
if(break_pressed()) goto shutdown;/* don't get file if we aborted experiment */
if(our_file_name[0]) /* make sure we created a file */
receive_data_file(our_file_name, "", 0); /* transfer the file, ask for a local name */
shutdown: /* CLEANUP */
close_expt_graphics(); /* tell EXPTSPPT to release window */
close_eyelink_connection(); /* disconnect from tracker */
return 0;
}
app_main()
{
int i, j;
char our_file_name[260] = "TEST";
if(open_eyelink_connection(0)) return -1; // abort if we can't open link
set_offline_mode();
flush_getkey_queue(); // initialize getkey() system
is_eyelink2 = (2 == eyelink_get_tracker_version(NULL) );
get_display_information(&dispinfo); // get window size, characteristics
// NOTE: Camera display does not support 16-color modes
// NOTE: Picture display examples don't work well with 256-color modes
// However, all other sample programs should work well.
if(dispinfo.palsize==16) // 16-color modes not functional
{
alert_printf("This program cannot use 16-color displays");
goto shutdown;
}
if(dispinfo.refresh < 40) // wait_for_refresh doesn't work!
{
alert_printf("No refresh synchroniztion available!");
}
if(dispinfo.palsize) // 256-color modes: palettes not supported by this example
{
alert_printf("This program is not optimized for 256-color displays");
}
//SEAN -display window
if(make_full_screen_window(application_instance)) goto shutdown; // create the window
if(init_expt_graphics(full_screen_window, NULL)) goto shutdown; // register window with EXPTSPPT
i = SCRWIDTH/60; // select best size for calibration target
j = SCRWIDTH/300; // and focal spot in target
if(j < 2) j = 2;
set_target_size(i, j); // tell DLL the size of target features
target_foreground_color = RGB(0,0,0); // color of calibration target
target_background_color = RGB(128,128,128); // background for calibration and drift correction
set_calibration_colors(target_foreground_color, target_background_color); // tell EXPTSPPT the colors
set_cal_sounds("", "", "");
set_dcorr_sounds("", "off", "off");
// draw a title screen
// SEAN
clear_full_screen_window(target_background_color); // clear screen
get_new_font("Times Roman", SCRHEIGHT/32, 1); // select a font
// Draw text
graphic_printf(target_foreground_color, target_background_color, 1, SCRWIDTH/2, 1*SCRHEIGHT/30,
"EyeLink Demonstration Experiment: Sample Code");
graphic_printf(target_foreground_color, target_background_color, 1, SCRWIDTH/2, 2*SCRHEIGHT/30,
"Included with the Experiment Programming Kit for Windows");
graphic_printf(target_foreground_color, target_background_color, 1, SCRWIDTH/2, 3*SCRHEIGHT/30,
"All code is Copyright (c) 1997-2002 SR Research Ltd.");
graphic_printf(target_foreground_color, target_background_color, 0, SCRWIDTH/5, 4*SCRHEIGHT/30,
"Source code may be used as template for your experiments.");
//SEAN - file i/o
i = edit_dialog(full_screen_window, "Create EDF File", // Get the EDF file name
"Enter Tracker EDF file name:", our_file_name, 8);
if(i==-1) goto shutdown; // ALT-F4: terminate
if(i==1) our_file_name[0] = 0; // Cancelled: No file name
if(our_file_name[0]) // If file name set, open it
{
if(!strstr(our_file_name, ".")) strcat(our_file_name, ".EDF"); // add extension
i = open_data_file(our_file_name); // open file
if(i!=0) // check for error
{
alert_printf("Cannot create EDF file '%s'", our_file_name);
goto shutdown;
} // add title to preamble
eyecmd_printf("add_file_preamble_text 'RECORDED BY %s' ", program_name);
}
// Now configure tracker for display resolution
eyecmd_printf("screen_pixel_coords = %ld %ld %ld %ld", // Set display resolution
dispinfo.left, dispinfo.top, dispinfo.right, dispinfo.bottom);
eyecmd_printf("calibration_type = HV9"); // Setup calibration type
eyemsg_printf("DISPLAY_COORDS %ld %ld %ld %ld", // Add resolution to EDF file
dispinfo.left, dispinfo.top, dispinfo.right, dispinfo.bottom);
if(dispinfo.refresh>40)
eyemsg_printf("FRAMERATE %1.2f Hz.", dispinfo.refresh);
// SET UP TRACKER CONFIGURATION
// set parser saccade thresholds (conservative settings)
if(is_eyelink2)
{
eyecmd_printf("select_parser_configuration 0"); // 0 = standard sensitivity
}
else
{
eyecmd_printf("saccade_velocity_threshold = 35");
eyecmd_printf("saccade_acceleration_threshold = 9500");
}
// set EDF file contents
eyecmd_printf("file_event_filter = LEFT,RIGHT,FIXATION,SACCADE,BLINK,MESSAGE,BUTTON");
eyecmd_printf("file_sample_data = LEFT,RIGHT,GAZE,AREA,GAZERES,STATUS");
// set link data (used for gaze cursor)
eyecmd_printf("link_event_filter = LEFT,RIGHT,FIXATION,SACCADE,BLINK,BUTTON");
eyecmd_printf("link_sample_data = LEFT,RIGHT,GAZE,GAZERES,AREA,STATUS");
// Program button #5 for use in drift correction
eyecmd_printf("button_function 5 'accept_target_fixation'");
if(!eyelink_is_connected() || break_pressed()) goto end_expt; // make sure we're still alive
// RUN THE EXPERIMENTAL TRIALS (code depends on type of experiment)
// Calling run_trials() performs a calibration followed by trials
// This is equivalent to one block of an experiment
// It will return ABORT_EXPT if the program should exit
i = run_trials();
end_expt: // END: close, transfer EDF file
set_offline_mode(); // set offline mode so we can transfer file
pump_delay(500); // delay so tracker is ready
eyecmd_printf("close_data_file"); // close data file
if(break_pressed()) goto shutdown; // don't get file if we aborted experiment
if(our_file_name[0]) // make sure we created a file
receive_data_file(our_file_name, "", 0); // transfer the file, ask for a local name
shutdown: // CLEANUP
close_expt_graphics(); // tell EXPTSPPT to release window
close_eyelink_connection(); // disconnect from tracker
close_full_screen_window();
return 0;
}
int gaze_control_trial(UINT32 time_limit)
{
UINT32 trial_start; /* trial start time (for timeout) */
UINT32 drawing_time; /* retrace-to-draw delay*/
int button; /* the button pressed (0 if timeout) */
int error; /* trial result code*/
ALLF_DATA evt; /* buffer to hold sample and event data*/
int eye_used = -1; /* indicates which eye's data to display*/
int i;
SDL_Surface *gbm; /* The bitmap containing the stimulus display*/
/* This supplies the title at the bottom of the eyetracker display */
eyecmd_printf("record_status_message 'GAZE CONTROL TRIAL' ");
/*
Always send a TRIALID message before starting to record.
It should contain trial condition data required for analysis.
*/
eyemsg_printf("TRIALID CONTROL");
/* TRIAL_VAR_DATA message is recorded for EyeLink Data Viewer analysis
It specifies the list of trial variables value for the trial
This must be specified within the scope of an individual trial (i.e., after
"TRIALID" and before "TRIAL_RESULT")
*/
eyemsg_printf("!V TRIAL_VAR_DATA GAZECTRL");
/*
IMGLOAD command is recorded for EyeLink Data Viewer analysis
It displays a default image on the overlay mode of the trial viewer screen.
Writes the image filename + path info
*/
eyemsg_printf("!V IMGLOAD FILL images/grid.png");
/*
IAREA command is recorded for EyeLink Data Viewer analysis
It creates a set of interest areas by reading the segment files
Writes segmentation filename + path info
*/
eyemsg_printf("!V IAREA FILE segments/grid.ias");
/* Before recording, we place reference graphics on the EyeLink display*/
set_offline_mode(); /* Must be offline to draw to EyeLink screen*/
gbm = draw_grid_to_bitmap_segment("grid.ias", "segments", 1);;/* Draw bitmap and EyeLink reference graphics*/
segment_source = gbm;
/*
Save bitmap and transfer to the tracker pc.
Since it takes a long to save the bitmap to the file, the
value of sv_options should be set as SV_NOREPLACE to save time
*/
bitmap_save_and_backdrop(gbm, 0, 0, 0, 0, "grid.png", "images", SV_NOREPLACE,
0, 0, (UINT16)(BX_MAXCONTRAST|((eyelink_get_tracker_version(NULL)>=2)?0:BX_GRAYSCALE)));
/* DO PRE-TRIAL DRIFT CORRECTION */
/* We repeat if ESC key pressed to do setup. */
while(1)
{ /* Check link often so we can exit if tracker stopped*/
if(!eyelink_is_connected()) return ABORT_EXPT;
/* We let do_drift_correct() draw target in this example*/
/* 3rd argument would be 0 if we already drew the display*/
error = do_drift_correct((INT16)(SCRWIDTH/2), (INT16)(SCRHEIGHT/2), 1, 1);
/* repeat if ESC was pressed to access Setup menu */
if(error!=27) break;
}
clear_full_screen_window(target_background_color); /* make sure display is blank*/
/* Configure EyeLink to send fixation updates every 50 msec*/
eyecmd_printf("link_event_filter = LEFT,RIGHT,FIXUPDATE");
eyecmd_printf("fixation_update_interval = 50");
eyecmd_printf("fixation_update_accumulate = 50");
init_regions(); /* Initialize regions for this display*/
/*
Start data recording to EDF file, BEFORE DISPLAYING STIMULUS
You should always start recording 50-100 msec before required
otherwise you may lose a few msec of data
*/
error = start_recording(1,1,0,1); /* send events only through link*/
if(error != 0) /* ERROR: couldn't start recording*/
{
SDL_FreeSurface(gbm); /* Be sure to delete bitmap before exiting!*/
return error; /* Return the error code*/
}
/* record for 100 msec before displaying stimulus */
begin_realtime_mode(100); /* Windows 2000/XP: no interruptions from now on*/
/*
DISPLAY OUR IMAGE TO SUBJECT by copying bitmap to display
Because of faster drawing speeds and good refresh locking,
we now place the stimulus onset message just after display refresh
and before drawing the stimulus. This is accurate and will allow
drawing a new stimulus each display refresh.
However, we do NOT send the message after the retrace--this may take too long
instead, we add a number to the message that represents the delay
from the event to the message in msec
*/
/* COPY BITMAP to display*/
SDL_BlitSurface(gbm, NULL, window,NULL);
Flip(window);
drawing_time = current_msec(); /* time of retrace*/
trial_start = drawing_time;
SDL_BlitSurface(gbm, NULL, window,NULL);
/* delay from retrace (time to draw)*/
drawing_time = current_msec()-drawing_time;
/* message for RT recording in analysis */
eyemsg_printf("%d DISPLAY ON", drawing_time);
/* message marks zero-plot time for EDFVIEW */
eyemsg_printf("SYNCTIME %d", drawing_time);
/* Print a title for the trial (for demo only)*/
get_new_font("Times Roman", 24, 1);
graphic_printf(window,target_foreground_color, NONE, SCRWIDTH/2, 24, "Gaze Control Trial");
if(!eyelink_wait_for_block_start(100, 0, 1)) /* wait for link event data*/
{
end_trial();
alert_printf("ERROR: No link events received!");
return TRIAL_ERROR;
}
eye_used = eyelink_eye_available(); /* determine which eye(s) are 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;
}
/* Now get ready for trial loop*/
eyelink_flush_keybuttons(0); /* reset keys and buttons from tracker */
/*
we don't use getkey() especially in a time-critical trial
as Windows may interrupt us and cause an unpredicatable delay
so we would use buttons or tracker keys only
Trial loop: till timeout or response -- added code for processing
FIXUPDATE events
*/
while(1)
{
/* First, check if recording aborted */
if((error=check_recording())!=0) return error;
/* Check if trial time limit expired*/
if(current_time() > trial_start+time_limit)
{
eyemsg_printf("TIMEOUT"); /* message to log the timeout */
end_trial(); /* local function to stop recording*/
button = 0; /* trial result message is 0 if timeout */
break; /* exit trial loop*/
}
if(break_pressed()) /* check for program termination or ALT-F4 or CTRL-C keys*/
{
end_trial(); /* local function to stop recording*/
return ABORT_EXPT; /* return this code to terminate experiment*/
}
/* check for local ESC key to abort trial (useful in debugging) */
if(escape_pressed())
{
end_trial(); /* local function to stop recording*/
return SKIP_TRIAL; /* return this code if trial terminated*/
}
/* BUTTON RESPONSE TEST */
/* Check for eye-tracker buttons pressed
/* This is the preferred way to get response data or end trials */
button = eyelink_last_button_press(NULL);
if(button!=0) /* button number, or 0 if none pressed*/
{
/* message to log the button press*/
eyemsg_printf("ENDBUTTON %d", button);
/* local function to stop recording*/
end_trial();
break; /* exit trial loop*/
}
/* GET FIXUPDATE EVENTS, PROCESS*/
i = eyelink_get_next_data(NULL); /* Check for data from link*/
if(i == FIXUPDATE) /* only process FIXUPDATE events*/
{
/* get a copy of the FIXUPDATE event */
eyelink_get_float_data(&evt);
/* only process if it's from the desired eye?*/
if(evt.fe.eye == eye_used)
{
/* get average position and duration of the update */
process_fixupdate((int)(evt.fe.gavx), (int)(evt.fe.gavy),/* Process event */
evt.fe.entime-evt.fe.sttime);
}
}
}/* end of loop*/
/* report response result: 0=timeout, else button number*/
eyemsg_printf("TRIAL_RESULT %d", button);
/* Call this at the end of the trial, to handle special conditions*/
SDL_FreeSurface(gbm);
segment_source = NULL;
return check_record_exit();
}
int record_mode_display(void)
{
ALLF_DATA evt;
UINT16 key;
int eye_used = -1; /* which eye to show gaze for */
float x, y; /* gaze position */
float ox=-1, oy=-1; /* old gaze position (to determine change) */
/* create font for position display */
get_new_font( "Arial", SCRWIDTH/50, 0);
while(getkey()); /* dump any pending local keys */
/*enable link data reception without changing tracker mode */
eyelink_reset_data(1);
initialize_cursor(window, SCRWIDTH/50);
eyelink_data_switch(RECORD_LINK_SAMPLES | RECORD_LINK_EVENTS);
while(1) /* loop while in record mode */
{
if(eyelink_tracker_mode() != EL_RECORD_MODE) break;
key = getkey(); /* Local keys/abort test */
if(key==TERMINATE_KEY) /* test ALT-F4 or end of execution */
break;
else if(key) /* OTHER: echo to tracker for control */
eyelink_send_keybutton(key,0,KB_PRESS);
/* CODE FOR PLOTTING GAZE CURSOR */
if(eyelink_newest_float_sample(NULL)>0) /* new sample? */
{
eyelink_newest_float_sample(&evt); /* get the sample data */
if(eye_used == -1) /* set which eye to track by first sample */
{
eye_used = eyelink_eye_available();
if(eye_used == BINOCULAR) /* use left eye if both tracked */
eye_used = LEFT_EYE;
}
else
{
x = evt.fs.gx[eye_used]; /* get gaze position from sample */
y = evt.fs.gy[eye_used];
if(x!=MISSING_DATA && y!=MISSING_DATA &&
evt.fs.pa[eye_used]>0) /* plot if not in blink */
{ /* plot in local coords */
draw_gaze_cursor(track2local_x(x),
track2local_y(y));
/* report gaze position (tracker coords) */
{
SDL_Rect r = {(INT16)(SCRWIDTH*0.87), 0, (INT16)(window->w -SCRWIDTH*0.87), 50};
SDL_FillRect(window,&r,SDL_MapRGB(window->format,0, 0, 0));
graphic_printf(window, target_foreground_color, NONE, (int)(SCRWIDTH*0.87), 0, " %4.0f ", x);
graphic_printf(window, target_foreground_color, NONE, (int)(SCRWIDTH*0.93), 0, " %4.0f ", y);
}
ox = x;
oy = y;
}
else
{
erase_gaze_cursor(); /* hide cursor during blink */
}
/* print tracker timestamp of sample */
{
SDL_Rect r = {(INT16)(SCRWIDTH*0.75), 0, (INT16)(SCRWIDTH*0.87 -SCRWIDTH*0.75), 50};
SDL_FillRect(window,&r,SDL_MapRGB(window->format,0, 0, 0));
graphic_printf(window,target_foreground_color, NONE, (int)(SCRWIDTH*0.75), 0, " % 8d ", evt.fs.time);
}
}
}
}
erase_gaze_cursor(); /* erase gaze cursor if visible */
return 0;
}