% code to run a simple oddball paradigm
% O. Krigolson June 15, 2018

clear all;                          % clears all variables
close all;                          % closes all files
clc;                                % clear screen
HideCursor;                         % hide the cursor
rng('shuffle');                     % this seeds the random number generator to be based on the clock

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

numberOfBlocks = 1;                 % define the number of blocks
numberOfTrials = 200;               % define the number of trials

[win, rect] = Screen('OpenWindow', 0, [0 0 0],[0 0 400 400], 32, 2);  % Set up graphics window

xMid = round(0.5*(r1(3)-r1(1)));   % determine the x midpoint of the screen
yMid = round(0.5*(r1(4)-r1(2)));   % determine the y midpoint of the screen

oddBallColour = [255 0 0];         % the oddball colour
controlColour = [0 255 0];         % the control colour

trialType(1:50) = 1;                % oddball trials
trialType(51:200) = 2;              % control trials
trialType = shuffle(trialType);     % randomize it

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% MAIN PROGRAM LOOP

% loop through the number of blocks
for blockCounter = 1:numberOfBlocks
    
    % loop through the number of trials
    for trialCounter = 1:numberOfTrials
                    
        % determine the trial type for the current trial
        currentTrialType = trialType(trialCounter);
        
        % draw a small square as a fixation cross
        Screen(win,'FillRect',[255 255 255],[xMid-5 yMid-5 xMid+5 yMid+5]);
        Screen('Flip', win);            
        
        % wait for some amount of time
        fixationTime = 0.4 + rand(1)*0.2;
        WaitSecs(fixationTime);
            
        % draw either the oddball or control square dependent on the
        % current trial type
        if currentTrialType == 1
            Screen(win,'FillRect',oddBallColour,[xMid-20 yMid-20 xMid+20 yMid+20]);
        else
            Screen(win,'FillRect',controlColour,[xMid-20 yMid-20 xMid+20 yMid+20]);
        end
        Screen('Flip', win);
        
        % send markers HERE... EEG experiments ONLY!
        if currentTrialType == 1
            % SEND ODDBALL MARKER
        else
            % SEND CONTROL MARKER
        end
        
        % wait for some amount of time
        circleTime = 0.8 + rand(1)*0.2;
        WaitSecs(circleTime);
     
    end

end

screen('CloseAll');		% Close all PsychToolbox windows.
ShowCursor;				% Put cursor back on.