NHP-pRF/Experiment_code/Tracker-MRI/TRACKER_PTB/RETINOTOPY/engine/DasCheck.m

function [Hit Time] = DasCheck

global Par
persistent PC %cached previous eye position
persistent LObj %cached handel to plot object

%        persistent SObj %cached handel to plot object
%        persistent Tick %every tick update noise plot

% Now that LPStat is a MEX file, it's 0-based instead of 1-based
Hit = LPStat(1);   %Hit yes or no
Time = LPStat(0);  %time

POS = dasgetposition();

P = POS.*Par.ZOOM; %average position over window initialized in DasIni
% eye position to global to allow logging
Par.CurrEyePos = [POS(1) POS(2)];

if  ishandle(LObj)
    addpoints(LObj,[PC(1) P(1)],[PC(2) P(2)]);
    if strcmp(Par.tracker_version, 'tracker_dark')
        set(LObj,'Color','w')
    end
else
    LObj = animatedline( [P(1) P(1)],  [P(2) P(2)], 'MaximumNumPoints',100);
    if strcmp(Par.tracker_version, 'tracker_dark')
        set(LObj,'Color','w')
    end
end

%         if isempty(Tick) || Tick > Time
%              Tick = Time;
%         end
%                 if  Time - Tick > 200 && Par.NoiseUpdate %update every 200 ms
%                     P = dasgetnoise();
%                     %2* standard error of noise in x & y direction
%                     SDx = ([-P(1) 0 P(1) 0 -P(1)] + Par.OFFx)* Par.ZOOM;
%                     SDy = ([0 P(2) 0 -P(2) 0]+ Par.OFFy)* Par.ZOOM;
%                     if  isempty(SObj) || ~ishandle(SObj)
%                         SObj = line( 'XData', SDx,  'YData', SDy, 'color', 'g', 'EraseMode','none');
%
%                     else
%                         set(SObj, 'XData', SDx,  'YData', SDy)
%
%                     end
%                     Tick = Time;
%                 end

drawnow %update screen
% cache the following values
PC = P;