% 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'); % Define a simple spiral texture by defining X and Y coordinates with the % meshgrid command, converting these to polar coordinates and finally % defining the spiral texture [x, y] = meshgrid(-120:1:120, -120:1:120); [th, r] = cart2pol(x, y); wheel = grey + inc .* cos(pi * th); % Make our sprial texure into a screen texture for drawing spiralTexture = Screen('MakeTexture', window, wheel); % We are going to draw four textures to show how a black and white texture % can be color modulated upon drawing. yPos = yCenter; xPos = linspace(screenXpixels * 0.2, screenXpixels * 0.8, 4); % Define the destination rectangles for our spiral textures. For this demo % these will be the same size as out actualy texture, but this doesn't have % to be the case. See: ScaleSpiralTextureDemo and CheckerboardTextureDemo. [s1, s2] = size(x); baseRect = [0 0 s1 s2]; dstRects = nan(4, 4); for i = 1:4 dstRects(:, i) = CenterRectOnPointd(baseRect, xPos(i), yPos); end % Color Modulation colorMod = [1 1 1; 1 0 0; 0 1 0; 0 0 1]'; % Batch Draw all of the texures to screen Screen('DrawTextures', window, spiralTexture, [],... dstRects, [], [], [], colorMod); % Flip to the screen Screen('Flip', window); % Wait for a key press KbStrokeWait; % Clear the screen sca;