task04.m

function task04( logpars, PTB, LPT)
% 3-alternative forced choice task

ver                 = '2.0';
fprintf('3-alternative forced choice task version %s\n', ver);
fprintf('\n\n');
%% init experiment structure

EXP                 = {};
EXP.stimsdir        = fullfile('textures-03');
EXP.assetsdir       = fullfile('assets');
EXP.baseImg         = [0 0 800 600];
EXP.baseImgSource   = [0 0 800 600];
EXP.framePix        = 4;
EXP.dotColor        = [0 1; 0 1; 0 1];
EXP.dotSize         = [20 14];
EXP.fixCrossDimPix  = 80;
EXP.fixCrossWidth   = 4;
EXP.xCoords         = [-EXP.fixCrossDimPix EXP.fixCrossDimPix 0 0];
EXP.yCoords         = [0 0 -EXP.fixCrossDimPix EXP.fixCrossDimPix];
EXP.allCoords       = [EXP.xCoords; EXP.yCoords];
EXP.afcInstruction  = 'Was wäre jetzt am wahrscheinlichsten gewesen?';
EXP.afcInst_yaxis   = PTB.yCenter - 200;
EXP.markerTrialOn   = 2;
EXP.markerTrialOff  = 4;
EXP.markerStartTask = 150;
EXP.markerEndTask   = 152;
EXP.RespFeedSec     = .25;
EXP.sourceDuration  = 3;
EXP.iti             = 2;
EXP.keyCodeLeft     = KbName('LeftArrow');
EXP.keyCodeCenter   = KbName('DownArrow');
EXP.keyCodeRight    = KbName('RightArrow');


%% get randomization
if str2double(logpars.subjid) == 1000
    EXP.id          = 1;
else
    EXP.id          = str2double(logpars.subjid);
    EXP.id          = EXP.id - 1000;
end

SI                  = load(fullfile(EXP.assetsdir, 'imgs_randomization.mat'));
EXP.imgs            = SI.XX(EXP.id, :);

S                   = load(fullfile(EXP.assetsdir, 'afc_randomization.mat'));
EXP.XX              = S.XX(EXP.id).X;



%% draw screen textures

% prepare image size for question options
if logpars.smallscreen == 1
    EXP.baseImg = round(EXP.baseImg*.3);
elseif logpars.smallscreen == 2
    EXP.baseImg = round(EXP.baseImg*.1);
else
    EXP.baseImg = round(EXP.baseImg*.5);
end

% scale single source images to screensize
if logpars.smallscreen == 1
    EXP.baseImgSource         = round(EXP.baseImgSource*.66);
elseif logpars.smallscreen == 2
    EXP.baseImgSource         = round(EXP.baseImgSource*.33);
end

% load images and rescale them
EXP.textures            = cell(length(EXP.imgs), 1);
for i=1:length(EXP.imgs)
    img                 = imread(fullfile(EXP.stimsdir, EXP.imgs{i}));
    img                 = imresize(img, flip(EXP.baseImg(3:4)));
    EXP.textures{i}     = Screen('MakeTexture', PTB.window, img);
    % Show init screen
    text = sprintf('%s %d%%', 'Loading resources...', round(i/length(EXP.imgs)*100));
    drawInstructions(PTB.window, text);
    Screen('Flip', PTB.window);
end
clear img;

% load images and rescale them
EXP.texturesSource      = cell(length(EXP.imgs), 1);
for i=1:length(EXP.imgs)
    img                 = imread(fullfile(EXP.stimsdir, EXP.imgs{i}));
    img                 = imresize(img, flip(EXP.baseImgSource(3:4)));
    EXP.texturesSource{i} = Screen('MakeTexture', PTB.window, img);
    % Show init screen
    text = sprintf('%s %d%%', 'Loading resources...', round(i/length(EXP.imgs)*100));
    drawInstructions(PTB.window, text);
    Screen('Flip', PTB.window);
end
clear img;

centeredImgSource       = CenterRectOnPointd(EXP.baseImgSource, PTB.xCenter, PTB.yCenter);
centeredImgLeft         = CenterRectOnPointd(EXP.baseImg, PTB.xCenter*.5, PTB.yCenter);
centeredImgCenter       = CenterRectOnPointd(EXP.baseImg, PTB.xCenter, PTB.yCenter);
centeredImgRight        = CenterRectOnPointd(EXP.baseImg, PTB.xCenter*1.5, PTB.yCenter);

%% init logfile
fprintf('\n\n');
fprintf('Initialising log files...\n')

logfile                 = fopen(logpars.logfilename,'w+');
fprintf(logfile, '%s', ...
    sprintf(repmat('%s',1,5), ...
    'trial,', ...   
    'conditionSource,', ...
    'conditionLeft,', ...
    'conditionCenter,', ...
    'conditionRight,', ...
    'pictureSource,', ...
    'pictureLeft,', ...      
    'pictureCenter,', ...
    'pictureRight,', ...     
    'decision,', ...        
    'decisionRt,')...        
    );
fprintf(logfile, '\n');
fclose(logfile);

%% init keyboard input
fprintf('\n\n');
fprintf('Initialising keyboard logger...\n')
% [keyboardIndices, productNames, allInfos] = GetKeyboardIndices;
kblog                   = Keylogger();

%% Welcome screen
fprintf('\n\n');
fprintf('Showing instructions...\n')

text = {...
    'Ihnen werden verschiedene Farben in einer Reihenfolge präsentiert.\n ' ...
    'Auf eine Farbe folgen drei weitere Farben.\n' ...
    'Wenn Sie drei Farben sehen, wählen Sie diejenige aus,\n' ...
    'die entsprechend Ihrer Erfahrung aus früheren Aufgaben nach dem vorherigen Farbbild erscheint.\n' ... 
    'Wenn Sie unsicher sind, welche Farbe Sie wählen sollen, folgen Sie Ihrer Intuition.\n\n' ...
    'Benutzen Sie die Tastatur, um Antworten zu geben.\n', ...
    'Um die Farbe auf der linken Seite auszuwählen, drücken Sie PFEIL LINKS.\n', ...
    'Um die Farbe in der Mitte auszuwählen, drücken Sie PFEIL RUNTER.\n', ...
    'Um die Farbe auf der rechten Seite auszuwählen, drücken Sie PFEIL RECHTS.\n\n', ...
    'Seien Sie so schnell und genau wie möglich!\n\n' ...
    'Die Aufgabe wird nur wenige Minuten dauern.\n\n', ...
    'Drücken Sie den Pfeil nach links, um die Aufgabe zu beginnen...', ...
    };


drawInstructions(PTB.window, strjoin(text));
Screen('Flip', PTB.window);
RestrictKeysForKbCheck(KbName('LeftArrow'));
KbStrokeWait;
Screen('Flip', PTB.window);
RestrictKeysForKbCheck([]);

%% start data collection
fprintf('\n\n');
fprintf('Starting data collection...\n')

% start recording
WaitSecs(1);
LPT.sendMarker(EXP.markerStartTask);


%% Trial loop

if logpars.debugging
    nTrials = 4;
else
    nTrials = length(EXP.XX);
end

% make sure that only arrow keys are read by KbWait
% to make sure that a participant provides a valid response
RestrictKeysForKbCheck([KbName('LeftArrow') KbName('DownArrow') KbName('RightArrow')]);
for trial = 1:nTrials

    % start with the fixation cross
    if trial == 1
        vbl     = Screen('Flip', PTB.window);
        Screen('DrawLines', PTB.window, EXP.allCoords, ...
            EXP.fixCrossWidth, 0, [PTB.xCenter PTB.yCenter], 2);
        Screen('DrawDots', PTB.window, ...
            [PTB.xCenter PTB.xCenter; PTB.yCenter PTB.yCenter], ...
            EXP.dotSize, EXP.dotColor, [], 2);
        Screen('Flip', PTB.window, vbl + PTB.ifi/2);
        WaitSecs(EXP.iti);
    end

    Screen('DrawTexture', PTB.window, EXP.texturesSource{EXP.XX(trial,1)}, [], centeredImgSource);
    sourceOnset     = Screen('Flip', PTB.window);
    DrawFormattedText(PTB.window, EXP.afcInstruction, 'center', EXP.afcInst_yaxis, 0, 120, [], [], 1.5);
    Screen('DrawTexture', PTB.window, EXP.textures{EXP.XX(trial,2)}, [], centeredImgLeft);
    Screen('DrawTexture', PTB.window, EXP.textures{EXP.XX(trial,3)}, [], centeredImgCenter);
    Screen('DrawTexture', PTB.window, EXP.textures{EXP.XX(trial,4)}, [], centeredImgRight);
    optionsOnset    = Screen('Flip', PTB.window, sourceOnset + EXP.sourceDuration + PTB.ifi/2, 1);
    LPT.sendMarker(EXP.markerTrialOn);
    kblog.startRecording(optionsOnset);
    KbStrokeWait;


   % log key response
    keypress    = kblog.dumpLog();
    response    = 'N/A';
    RT          = 'N/A';
    for p=1:length(keypress)
        % kblog still logs all keypresses
        if keypress(p).pressed ...
                && ismember(keypress(p).keyCode, [EXP.keyCodeLeft EXP.keyCodeCenter EXP.keyCodeRight])
            keyCode = keypress(p).keyCode;
            RT      = keypress(p).onset;
            if keyCode == EXP.keyCodeLeft
                response = 1;
                Screen('FrameRect', PTB.window, 1, centeredImgLeft, EXP.framePix);
            elseif keyCode == EXP.keyCodeCenter
                response = 2;
                Screen('FrameRect', PTB.window, 1, centeredImgCenter, EXP.framePix);
            elseif keyCode == EXP.keyCodeRight
                response = 3;
                Screen('FrameRect', PTB.window, 1, centeredImgRight, EXP.framePix);
            break
            end
        end
    end

    vbl     = Screen('Flip', PTB.window);
    Screen('DrawLines', PTB.window, EXP.allCoords, ...
        EXP.fixCrossWidth, 0, [PTB.xCenter PTB.yCenter], 2);
    Screen('DrawDots', PTB.window, ...
        [PTB.xCenter PTB.xCenter; PTB.yCenter PTB.yCenter], ...
        EXP.dotSize, EXP.dotColor, [], 2);
    Screen('Flip', PTB.window, vbl + EXP.RespFeedSec + PTB.ifi/2);

    % log response
    logfile             = fopen(logpars.logfilename,'a+');
    fprintf(logfile, '%s,', ...
        string(trial), ...
        string(EXP.XX(trial,1)), ...
        string(EXP.XX(trial,2)), ...
        string(EXP.XX(trial,3)), ...
        string(EXP.XX(trial,4)), ...
        string(EXP.imgs{EXP.XX(trial,1)}), ...
        string(EXP.imgs{EXP.XX(trial,2)}), ...
        string(EXP.imgs{EXP.XX(trial,3)}), ...
        string(EXP.imgs{EXP.XX(trial,4)}), ...
        string(response), ...
        string(RT));
    fprintf(logfile, '\n');
    fclose(logfile);

    WaitSecs(EXP.iti);

end

%% save data

fprintf('\n\n');
fprintf('Saving data...\n');
LPT.sendMarker(EXP.markerEndTask);

end