OpenOffscr​eenWindowを​使ってウィンドウを隠​したい

現在実行するとOpenWindowによって実行画面が表示されるのですが、それだと、タブレットに文字を書いて表示しているfigureの表示が少し遅れるため、その表示までの誤差をなくしたいと考えています。

その方法としてOpenOffscreenWindowが使えるのではないかと思っているのですが、エラーが起こりうまく動きません。

OpenWindowの部分をOpenOffscreenWindowに変更したり、OpenWindowの次の行にOpenOffscreenWindowを入れてみたりしているのですが

「Tried to call WinTab function, but it isn't initialized yet! Call code 0 (Initialize) first!」このエラーコードが出てしまいます。

しかし、下記の２行目の部分でWinTabMexを初期化しているはずです。

[wPtr rect] = Screen('OpenWindow', 0 ,256, [0 500 1000 1100]) 
     WinTabMex(0, wPtr); %Initialize tablet driver, connect it to 'wPtr'     

OpenOffscreenWindowをどう定義したらよいかわかっていません。

わかる方いましたら教えていただけないでしょうか。

全体のコードになります。

function fastLoop
% function fastLoop
% 
% Opens a PTB Screen, attaches a tablet to the associated screen pointer wPtr and dumps out the contents of an event queue.
%
%
% pkt = WinTabMex(5) reads the latest data point out of a tablet's event queue. This queue is a buffer that can hold around 50 data points.
% This queue begins filling up after a call to WinTabMex(2), which empties the queue, and can be used to record movement data during 
% stimulus presentation in a 'fast loop' (see fastLoop.m). 
%
% pkt is a 8x1 column vector
% 
% tabletTestData.mat:
%           xPos                = pkt(1), x axis position (tablet coordinates)
%           yPos                = pkt(2), y axis position (tablet coordinates)
%           zPos                = pkt(3), z axis position (tablet coordinates)
%           buttonState         = pkt(4), encoded button state (works a little erratically)
%           serialNumber        = pkt(5)
%           tabletTimeStamp     = pkt(6), time in ms from the tablet
%           penStatus           = pkt(7), signals various events (eg penOutOfRange)
%           penChange           = pkt(8), flags what has changed since the last sample
%
%pkt(1:6) are straightforward, pkt(7:8) need some work on figuring out what it all means
%
%Andrew D. Wilson, 2009 ([e-mail])

  
KbName('UnifyKeyNames');
spaceKeyID = KbName('space');

data = [];
   
try
   
  [wPtr rect] = Screen('OpenWindow', 0 ,256, [0 500 1000 1100]) 
     WinTabMex(0, wPtr); %Initialize tablet driver, connect it to 'wPtr'     
     
     
   [old,new]=WinTabMex(4,500);
    
    %PTB things
    Priority(1);
    ListenChar(2);
    %HideCursor;
    black = BlackIndex(wPtr);
    white = WhiteIndex(wPtr);

    
    %*******************************************************************************************
    %Loads a window and waits for input to start recording - just for getting set up and ready
    
    
    %instructions = 'Place the stylus on the tablet and press the space bar to begin recording';
%     instructions = 'initializing..';
    
    
%     [instructionsX instructionsY] = centreText(wPtr, instructions, 15);
%     Screen('DrawText', wPtr, instructions, instructionsX, instructionsY, black); Screen(wPtr, 'Flip');
    %スペースバーを待つ
%    [keyIsDown, secs, keyCode] = KbCheck;
%    while keyCode(spaceKeyID)~=1
%        [keyIsDown, secs, keyCode] = KbCheck;
       
%    end    
    

    %*******************************************************************************************
  
    WinTabMex(2); %Empties the packet queue in preparation for collecting actual data
    information = 'Event queue is filling up...you will be able to retrive up to 50 events (500ms @ 100Hz)';
    [informationX informationY] = centreText(wPtr, information, 15);
    Screen('DrawText', wPtr, information, informationX, informationY, black); 
    Screen(wPtr, 'Flip');
   
   
  WaitSecs(3);
    
   %Fast loop to dump all data from the queue into a variable. Each call to WintabMex(5) pulls a data point off the top of the queue, and
    %this loops runs as fast as Matlab can execute it until the queue is drained
    %
    %NB: This loop to drain the queue runs after the data is collected


    
h = animatedline;
%  count=0;

% drawnow
while 1
    pkt = WinTabMex(5);
    if isempty(pkt) %キューが空です
        %data = [data; pkt]; %breakが呼び出されたことを示す
        break;
%           count=count+1;
%            if count==10000
%                break;
%            end        
%           continue;
    else
%           count=0;
        data = [data pkt];
        

        addpoints(h,pkt(1),pkt(2));
         drawnow
    end
    status = uint32(pkt(7));
    if bitget(status, 1)
        disp('Pen is outside the tablet');
    end
    if bitget(status, 2)
        disp('Queue overflow - packets getting lost');
    end
end
%     data
    data = data'  %Do it this way to suit the way Matlab memory preferences treat rows and columns, etc
    samplingRate = 1000 / mean(diff(data(1:end-1,6)));
    disp(['Your sampling rate appears to be ', int2str(samplingRate), 'Hz.']);

    endInstructions = 'Queue drained...pull the stylus away from the tablet';
    [endX endY] = centreText(wPtr, endInstructions, 15);
    Screen('DrawText', wPtr, endInstructions, endX, endY, black); 
    Screen(wPtr, 'Flip');
    WaitSecs(3);
    
    WinTabMex(3);  % Stop/Pause data acquisition.
    WinTabMex(1); % Shutdown driver.
    ListenChar(1);  ShowCursor;


    Screen('CloseAll');
catch
    disp('Quit with error (wintabfastLoop.m)');
    WinTabMex(3); 
    WinTabMex(1);
    ListenChar(1);  
    ShowCursor;
    Screen('CloseAll');
    
    tabletTestError = lasterror;
    message = tabletTestError(1).message
    identifier = tabletTestError(1).identifier
    stack = tabletTestError(1).stack;
    file = stack.file
    line = stack.line
end

function [x y] = centreText(wPtr, text, preferredFontSize)
%function [x y] = centreText(wPtr, text, preferredFontSize)
%
%For use with the Psychtoolbox. 
%Takes a window pointer & a string and returns the x,y coordinates that will centre the text if fed to Screen('DrawText')
%
%ARGUMENTS:
%wPtr = the window pointer returned by a call to Screen('OpenWindow')
%text = a string to be sent to the screen
%preferredFontSize = the maximum sized font you would like to have. If the text is too big, centreText will cycle through 
%   text sizes until it works and set it to the biggest that fits
%
%RETURN VALUES:
%[x y] = a vector with the (x,y) coordinates to centre that text.
%
%NB Requires that you have used Screen('OpenWindow')
%
%Andrew D. Wilson (v1.0.3; 11 April 2008)

x=-1; y=-1; %Allows loop to run once

while x<0
    Screen('TextSize', wPtr, preferredFontSize);

    [normBoundsRect, offsetBoundsRect]= Screen('TextBounds', wPtr, text);
    rect = Screen('Rect', wPtr);

    windowCentre = [rect(3)/2 rect(4)/2];
    textCentre = [normBoundsRect(3)/2 normBoundsRect(4)/2];

    x = windowCentre(1) - textCentre(1);
    y = windowCentre(2) - textCentre(2);
    
    if x < 0 || y < 0 %つまり、テキストが画面外に描画された場合
        preferredFontSize = preferredFontSize-1;
    end
   
end
  
return;

[Etsuo Maeda]

OpenOffscreenWindowなる関数はPsychtoolboxという3rd-party製のToolboxに含まれる関数のようです。

あちらのフォーラムで聞いてみれば答えが得られるかもしれません。

HTH