BubbleApertureDemo

% Clear the workspace and the screen
sca;
close all;
clear;

% 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);

% Define black and white
white = WhiteIndex(screenNumber);
black = BlackIndex(screenNumber);
grey = white / 2;
inc = white - grey;

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

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

% Query the frame duration
ifi = Screen('GetFlipInterval', window);

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

% Set up alpha-blending for smooth (anti-aliased) lines
Screen('BlendFunction', window, 'GL_SRC_ALPHA', 'GL_ONE_MINUS_SRC_ALPHA');

% Here we load in an image from file. This one is a image of rabbits that
% is included with PTB
theImageLocation = [PsychtoolboxRoot 'PsychDemos' filesep...
    'AlphaImageDemo' filesep 'konijntjes1024x768.jpg'];
theImage = imread(theImageLocation);

% Get the size of the image
[s1, s2, s3] = size(theImage);

% Here we check if the image is too big to fit on the screen and abort if
% it is. See ImageRescaleDemo to see how to rescale an image.
if s1 > screenYpixels || s2 > screenYpixels
    disp('ERROR! Image is too big to fit on the screen');
    sca;
    return;
end

% Make the image into a texture
imageTexture = Screen('MakeTexture', window, theImage);

% Make a gaussian aperture with the "alpha" channel
gaussDim = 50;
gaussSigma = gaussDim / 3;
[xm, ym] = meshgrid(-gaussDim:gaussDim, -gaussDim:gaussDim);
gauss = exp(-(((xm .^2) + (ym .^2)) ./ (2 * gaussSigma^2)));
[s1, s2] = size(gauss);
mask = ones(s1, s2, 2) * grey;
mask(:, :, 2) = white * (1 - gauss);
masktex = Screen('MakeTexture', window, mask);

% Make a grey texture to cover the full window
fullWindowMask = Screen('MakeTexture', window,...
    ones(screenYpixels, screenXpixels) .* grey);

% Make coordinates in which to draw the apertures into our full screen mask
[xg, yg] = meshgrid(-3:1:3, -3:1:3);
spacing = gaussDim * 2;
xg = xg .* spacing + screenXpixels / 2;
yg = yg .* spacing + screenYpixels / 2;
xg = reshape(xg, 1, numel(xg));
yg = reshape(yg, 1, numel(yg));

% Make the destination rectangles for the gaussian apertures
dstRects = nan(4, numel(xg));
for i = 1:numel(xg)
    dstRects(:, i) = CenterRectOnPointd([0 0 s1, s2], xg(i), yg(i));
end

% Draw the gaussian apertures  into our full screen aperture mask
Screen('DrawTextures', fullWindowMask, masktex, [], dstRects);

% Draw the image to the screen, unless otherwise specified PTB will draw
% the texture full size in the center of the screen. We first draw the
% image in its correct orientation.
Screen('DrawTexture', window, imageTexture, [], [], 0);
Screen('DrawTexture', window, fullWindowMask);

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

% Wait for key press
KbStrokeWait;

% Clear the screen
sca;