RTBoxClass_demo.m

% This demo does the same as RTBoxdemo_Orientation.m, except using RTBoxClass to
% control RTBox. The task is to identify the orientation of garbor. If garbor
% tilts to 11 o'clock, press left button; if to 1 o'clock, press right button.
% The result will be displayed in command window.

% 170423 Adapt it from RTBoxdemo_Orientation.m (Xiangrui.Li at gmail.com)

function RTBoxClass_demo(scrn)
if nargin<1, scrn = max(Screen('screens')); end % find last screen
nTrials = 10; % # of trials
timeout = 3; % timeout for RT reading
radius = 3; % garbor radius in visual degrees
dAngle = 5; % tilt degree from vertical
sf = 1; % spatial freq: cycles per deg
contrast = 0.3; % garbor contrast
ppd = 42; % display property: pixels per degree

% The record contains stim info and response. 
% We assign NaN to missed and unreasonable response.
record = nan(nTrials, 5); % 5 columns: iTrial tiltRight respCorrect RT startSecs
record(:,1) = 1:nTrials; % # of trial
LR = ones(nTrials,1); LR(1:round(nTrials/2)) = 0; % half ones, half zeros
record(:,2) = Shuffle(LR); % 1 for tilt right, 0 left

box = RTBoxClass(); % open RTBox, return class instance for later access
% box = RTBoxClass(''); % replace above line to simulate with keyboard
box.buttonNames({'left' 'left' 'right' 'right'}); % make 4 buttons like 2

[w, res] = Screen('OpenWindow', scrn, 127);  % open a gray screen
clnObj = onCleanup(@() sca); % nice trick to close window, but now for script
HideCursor;
ifi = Screen('GetFlipInterval', w); % flip interval

% print some instruction
Screen('TextSize', w, round(24/res(4)*1024)); % proportional font size
Screen('TextFont', w, 'Times'); % seems needed for Windows
str = ['This will test your RT to garbor orientation identification.\n\n' ...
    'We will do ' num2str(nTrials) ' trials. When you see a tilted garbor:\n\n' ...
    'press any of left buttons if it tilts to left,\n\n' ...
    'press any of right buttons if it tilts to right'];
[~, ny] = DrawFormattedText(w, str, 'center', 'center', [255 0 0]);
DrawFormattedText(w, 'Press any button to start', 'center', ny+50, 255);
Screen('Flip', w); % show instruction

% Generate a gabor with vertical orientation, will rotate +dAngle or -dAngle
imgsz = round(radius*ppd*2); % image size in pixels
rect = CenterRect([0 0 imgsz imgsz], res); % stim rect
[x, y] = meshgrid(linspace(-radius, radius, imgsz)); % symmetric coordinates
mask = exp(-(x.^2 + y.^2)/(radius/2)^2); % gaussian mask: 0 to 1
img = sin(2*pi*sf*x); % grating tilted left from vertical
img = img * contrast .* mask; % apply contrast and mask
img = uint8((img+1)*127); % convert from [-1 1] to [0 254]
tex = Screen('MakeTexture', w, img); % texture
clear x y mask img; % later, we need texture only

Priority(MaxPriority(w)); % raise priority for better timing
box.clear(); % remove any previous events
t0 = box.secs(1000); % wait 1000 s, or till any enabled event
tStr = datestr(now); % for record
Screen('FrameOval', w, 140, rect); % circle
vbl = Screen('Flip', w); %#ok turn off instruction, show circle

for i = 1:nTrials
    if record(i,2), angl = dAngle; else, angl = -dAngle; end % in deg
    Screen('DrawTexture', w, tex, [], rect, angl); % draw to buffer
    Screen('FrameOval', w, 140, rect); % circle
    
    WaitSecs(1+rand*2); % random interval for subject
    box.clear(); % clear right before stimulus onset of each trial
    vbl = Screen('Flip', w); % show stim, return onset time
    % box.TTL(record(i,2)+1); % EEG trial type marker: 1 left, 2 right
    
    record(i,5) = vbl-t0; % startSecs of the trial
    Screen('FrameOval', w, 140, rect); % circle
    Screen('Flip', w, vbl+ifi*1.5); % turn off stim and show circle
    
    [t, btn] = box.secs(timeout); % return computer time and button
    
    % check response
    if isempty(t), continue; end % no response, skip the trial
    t = t - vbl - ifi/2; % RT now, roughly calibrate offset
    if numel(t)>1 % more than 1 response
        fprintf(' #trial %2g: RT = ',i); fprintf('%8.4f',t); fprintf('\n');
        ind = find(t>0.1, 1); % find the 1st proper rt
        % you may set your criterion, for example t>0.2
        if isempty(ind), continue; end  % no reasonable response, skip trial
        t = t(ind); btn = btn(ind); % use the first reasonable response
    end
    
    % record correctness and RT
    record(i, 3:4) = [record(i,2)==strcmp(btn{1},'right') t];
end

Priority(0); % restore normal priority
box.close(); % release the serial port

% save myresult record t0;  % save result into MAT file

% display or save result
fid = 1; % display in command window
% fid = fopen('myresult.txt', 'w+'); % you should save result to a file
fprintf(fid, 't0 = %.4f\n',t0); % start time. may be useful for debug
fprintf(fid, 'Started at %s\n\n', tStr);
fprintf(fid, ' trial tiltRight respCorrect respTime startSecs\n');
fprintf(fid, '%6g %9g %11g %8.4f %.4f\n', record'); % one trial per row
fprintf(fid, '\nFinished at %s\n', datestr(now));
fclose('all'); % no complain for fid=1