% Clear the workspace sca; clear; close all; % Shuffle the random number generator so that we get randomly positioned % dots on each rune rng('shuffle'); %-------------------------------------------------------------------------- % Set up the screen %-------------------------------------------------------------------------- % Set the stereomode 6 for red-green anaglyph presentation. You will need % to view the image with the red filter over the left eye and the green % filter over the right eye. Note that with color filters you will get some % from of cross talk normally, unless you have matched the filtered well to % your screen, or compensated for this. stereoMode = 6; % Here we call some default settings for setting up Psychtoolbox PsychDefaultSetup(2); % Setup Psychtoolbox for OpenGL 3D rendering support and initialize the % mogl OpenGL for Matlab wrapper InitializeMatlabOpenGL; % Get the screen number screenid = max(Screen('Screens')); % Open the main window [window, windowRect] = PsychImaging('OpenWindow', screenid, 0,... [], 32, 2, stereoMode); % Show cleared start screen: Screen('Flip', window); % Screen size pixels [screenXpix, screenYpix] = Screen('WindowSize', window); % Set up alpha-blending for smooth (anti-aliased) edges to our dots Screen('BlendFunction', window, 'GL_SRC_ALPHA', 'GL_ONE_MINUS_SRC_ALPHA'); %-------------------------------------------------------------------------- % Set up the screen %-------------------------------------------------------------------------- % Set the size of the square to be a fraction of the screen size. This will % give us similar results on any demo system hopefully squareDimPix = screenXpix / 5; % For ease will will position dots +/- half of this size i.e. centered % around zero. When we draw to the screen we center the dots automatically. squareHalfDimPix = squareDimPix / 2; % Number of dots numDots = 500; % Dot base position in pixels for the left and right eye. As you will see % the vertical dot positions will be the same in both cases. dotPosXleft = (rand(1, numDots) .* 2 - 1) .* squareHalfDimPix; dotPosYleft = (rand(1, numDots) .* 2 - 1) .* squareHalfDimPix; dotPosXright = dotPosXleft; dotPosYright = dotPosYleft; % To shift the square in depth we need to shift the square by equal and % opposite amounts in the left and right eyes. To make the square appear % in front of the screen we need to shift the left eyes image to the right % and the right eyes image to the left. shifterPix = 10; dotPosXleft = dotPosXleft + shifterPix; dotPosXright = dotPosXright - shifterPix; % Dot diameter in pixels dotDiaPix = 6; %------------------------ % Drawing to the screen %------------------------ % When drawing in stereo we have to select which eyes buffer we are going % to draw in. These are labelled 0 for left and 1 for right. Note also, if % you wear your anaglyph glasses the opposite way around the depth will % reverse. % Select left-eye image buffer for drawing (buffer = 0) Screen('SelectStereoDrawBuffer', window, 0); % Now draw our left eyes dots Screen('DrawDots', window, [dotPosXleft; dotPosYleft], dotDiaPix,... [], [screenXpix / 2 screenYpix / 2], 2); % Select right-eye image buffer for drawing (buffer = 1) Screen('SelectStereoDrawBuffer', window, 1); % Now draw our right eyes dots Screen('DrawDots', window, [dotPosXright; dotPosYright], dotDiaPix,... [], [screenXpix / 2 screenYpix / 2], 2); % Flip to the screen Screen('Flip', window); % Wait for a button press to exit the demo KbStrokeWait; sca;