Matlab - how to draw pixels on a black full screen?

Question

I want matlab to show me a full screen, all black, and to be able to set pixels on it.

Is it even possible?

Answer 1

You can't totally do that using pure MATLAB code. On Windows, I tried different combinations, but the taskbar will still be on top (the one with the Start button):

%# 1)
sz = get(0, 'ScreenSize');
figure('Menubar','none', 'WindowStyle','modal', ...
    'Units','pixels', 'Position', [0 0 sz(3) sz(4)])

%# 2)
figure('Menubar','none', 'Units','normalized', 'Position',[0 0 1 1])

%# 3)
hFig = figure('Menubar','none', 'Units','normalized', 'Position',[0 0 1 1]);
set(hFig, 'Units','pixels')
p = get(hFig, 'Position');
set(hFig, 'Position', [1 31 p(3) p(4)-8]);

You would have to write a MEX function and call the the Win32 API directly. Fortunately, there should be existing submissions on FEX implementing such functionality.

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Here is an example of creating a full screen figure, and drawing points with the mouse. I am using the WindowAPI solution by Jan Simon

%# open fullscreen figure
hFig = figure('Menubar','none');
WindowAPI(hFig, 'Position','full');

%# setup axis
axes('Color','k', 'XLim',[0 1], 'YLim',[0 1], ...
    'Units','normalized', 'Position',[0 0 1 1], ...
    'ButtonDownFcn',@onClick)

The callback function:

function onClick(hObj,ev)
    %# draw point
    p  = get(hObj,'CurrentPoint');
    line(p(1,1), p(1,2), 'Color','r', 'LineStyle','none', ...
        'Marker','.', 'MarkerSize',40, 'Parent',hObj)
end

Answer 2

Check out psychophysics toolbox. It does exactly what you are looking for and more.