Detect a mousepress within specific coordinates?

1

Dear all,

I am new to matlab and psychtoolbox, and I have some issues with a code I didn’t write.

I have two rectangles appearing on my second screen, and the task is to click on the white one (nice beep). The black one giving a “bad beep” as a response.
My problem is that I can make both rectangles appear on the second screen, but the “click detection” uses coordinates of my rectangle but on my first screen. Can anyone help me with this ?

% Here we call some default settings for setting up Psychtoolbox
PsychDefaultSetup(2);

% Get the screen numbers
screens = Screen('Screens');

% Draw to the external screen if avaliable
screenNumber = max(screens);

% grey background
grey = [76 60 42]./100;

% Open an on screen window
[window, windowRect] = PsychImaging('OpenWindow', screenNumber, grey);

% Get the size of the on screen window
[screenXpixels, screenYpixels] = Screen('WindowSize', window);

% Get the centre coordinate of the window
[xCenter, yCenter] = RectCenter(windowRect);

% Make a base Rect of 500 by 500 pixels
baseRect = [0 0 500 500];


for i=1:numTrials

    posx=Shuffle([.25 .75]); % -> posx=Shuffle([posx(1) posx(2)])

squareXpos1 = round([screenXpixels * posx(1)]);
squareXpos2 = round([screenXpixels * posx(2)]);


% Set the colors to Red, Green and Blue
allColors1 = [1 1 1];
allColors2 = [0 0 0];

allRects1 = CenterRectOnPointd(baseRect, squareXpos1, yCenter);
allRects2 = CenterRectOnPointd(baseRect, squareXpos2, yCenter);

% Draw the rect to the screen
Screen('FillRect', window, allColors1, allRects1);
Screen('FillRect', window, allColors2, allRects2);

% Flip to the screen
Screen('Flip', window);


MousePress = 0;
while MousePress == 0 % wait for press
    [x,y,buttons] = GetMouse();
    
    MousePress=any(buttons);

end
if MousePress

    if ((x > allRects1(1) & x < allRects1(3)) & (y* 0.7 > allRects1(2) & y* 0.7 < allRects1(4)))==1

        Beeper(500, 2.5, .3)
        in = 1;
                 
    else
        Beeper(300, 2.5, .2)
        in = 0;

    in
end

Also, for now, when I click anywhere else than within the coordinates of the first rectangle, this counts as a bad response (which seems logical, using only “else” for the bad response), but I cannot manage to use only the coordinates of the second rectangle as a bad response and the background as “wait for a new press” without counting this as one trial. If you have a solution for this too… I might create another topic for this issue.

I hope that I am not asking too much, this is my first time on a forum ! :sweat_smile:
Thank you all in advance ! (Also, sorry if my english is far from perfect, frenchies are not that good with foreign languages…)

2

If is interpret correctly, these are the tools you need:
If wpnt is the pointer to your open window:

Screen(‘Rect’,wpnt) gives you the rect of the window, always [0 0 width height] if fullscreen. Screen(‘GlobalRect’) gives you where this window is among all your screens, so on the global desktop. That will give you the offset to apply to the (global) mouse coordinates to get them local to your window.

3

Thank you very much, I managed to fix my problem. Maybe not the conventional way, but it works ! :innocent:

Just added :
rect=Screen('GlobalRect',screenNumber)
at the top of my code, and modified my “click coordinates” as following (adding +rect(1) to the x coordinates) :
if ((x > allRects1(1) +rect(1) & x < allRects1(3) +rect(1)) & (y* 0.7 > allRects1(2) & y* 0.7 < allRects1(4)))==1

Thanks again ! Have a nice day !

4

It’s actually simpler:

[x,y,buttons] = GetMouse(window) will return [x,y] in window-local coordinates. [clicks,x,y,whichButton] = GetClicks(window) does the same, but waits for one or more mouse-clicks and returns x,y of 1st one in window local coordinates. But read help GetClicks to understand the timeout behaviour on multiple clicks etc. if your are into reaction times.

There’s also (help PsychRects for more) this gizmo:

inside = IsInRect(x,y,rect)

Hope it helps,
-mario

5

Oh… Much simpler indeed.
Works perfectly fine this way too ! ([x,y,buttons] = GetMouse(window) instead of adding the x axis pixels of my first screen to the coordinates of my rectangles for the clickable zone)

Thank you Mario ! Have a nice day ! :smiley:

6

Ah, I missed that as it is quite a bit down in the helptext of GetMouse :stuck_out_tongue: