% Clear the workspace and the screen close all; clear; sca % Here we call some default settings for setting up Psychtoolbox PsychDefaultSetup(2); % Get the screen numbers screens = Screen('Screens'); % Select the external screen if it is present, else revert to the native % screen screenNumber = max(screens); % Define black, white and grey black = BlackIndex(screenNumber); white = WhiteIndex(screenNumber); grey = white / 2; % Open an on screen window and color it grey [window, windowRect] = PsychImaging('OpenWindow', screenNumber, grey); % Set the blend funciton for the screen Screen('BlendFunction', window, 'GL_SRC_ALPHA', 'GL_ONE_MINUS_SRC_ALPHA'); % Get the size of the on screen window in pixels % For help see: Screen WindowSize? [screenXpixels, screenYpixels] = Screen('WindowSize', window); % Get the centre coordinate of the window in pixels % For help see: help RectCenter [xCenter, yCenter] = RectCenter(windowRect); % Draw text in the upper portion of the screen with the default font in red % and flipped horizontally Screen('TextSize', window, 70); DrawFormattedText(window, 'Hello World', 'center',... screenYpixels * 0.25, [1 0 0], [], 1); % Draw text in the middle of the screen in Courier in white and flipped % vertically Screen('TextSize', window, 80); Screen('TextFont', window, 'Courier'); DrawFormattedText(window, 'Hello World', 'center', 'center', white, [], [], 1); % Draw text in the bottom of the screen in Times in blue and flipped % horizontally and vertically i.e. upside down Screen('TextSize', window, 90); Screen('TextFont', window, 'Times'); DrawFormattedText(window, 'Hello World', 'center',... screenYpixels * 0.75, [0 0 1], [], 1, 1); % Flip to the screen Screen('Flip', window); % Now we have drawn to the screen we wait for a keyboard button press (any % key) to terminate the demo KbStrokeWait; % Clear the screen sca;