add devSandbox to develop PTB stimulation

Author: marcobarilari

devSandbox.m

@@ -0,0 +1,205 @@
+function devSandbox
+
+cfg = struct;
+
+cfg.backgroundColor = [ 127 127 127 ];
+
+cfg = devSandbox_initPTB(cfg);
+
+
+% -------------------------------------------------------------------------
+% -------------------------- SET YOUR VARS HERE ---------------------------
+% -------------------------------------------------------------------------
+
+% Define black and white
+white = WhiteIndex(cfg.screenNumber);
+black = BlackIndex(cfg.screenNumber);
+grey = white / 2;
+inc = white - grey;
+
+% Grating size in pixels
+gratingSizePix = 600;
+
+% Grating frequency in cycles / pixel
+freqCyclesPerPix = 0.01;
+
+% Drift speed cycles per second
+cyclesPerSecond = 1;
+
+% Contrast for our contrast modulation mask: 0 = mask has no effect, 1 = mask
+% will at its strongest part be completely opaque frameCounter.e. 0 and 100% contrast
+% respectively
+contrast = 0.8;
+
+% We set PTB to wait one frame before re-drawing
+waitframes = 1;
+
+% -------------------------------------------------------------------------
+
+try
+    
+% -------------------------------------------------------------------------
+% ------------------------------ PLAYGROUND -------------------------------
+% -------------------------------------------------------------------------
+    % Define Half-Size of the grating image.
+texsize = gratingSizePix / 2;
+
+% First we compute pixels per cycle rounded to the nearest pixel
+pixPerCycle = ceil(1 / freqCyclesPerPix);
+
+% Frequency in Radians
+freqRad = freqCyclesPerPix * 2 * pi;
+
+% This is the visible size of the grating
+visibleSize = 2 * texsize + 1;
+
+% Define our grating. Note it is only 1 pixel high. PTB will make it a full
+% grating upon drawing
+x = meshgrid(-texsize:texsize + pixPerCycle, 1);
+grating = grey * cos(freqRad*x) + inc;
+
+% Make a two layer mask filled with the background colour
+mask = ones(1, numel(x), 2) * grey;
+    
+% Place the grating in the 'alpha' channel of the mask
+mask(:, :, 2)= grating .* contrast;
+
+% Make our grating mask texture
+gratingMaskTex = Screen('MakeTexture', cfg.window, mask);
+
+% Make a black and white noise mask half the size of our grating. This will
+% be scaled upon drawing to make a "chunky" noise texture which our grating
+% will mask. Note the round function in here. For this demo we are simply
+% rounding the size to the nearest pixel, leaving PTB to do some scaling.
+noise = rand(round(visibleSize / 2)) .* white;
+
+% Make our noise texture
+noiseTex = Screen('MakeTexture', cfg.window, noise);
+
+% Make a destination rectangle for our textures and center this on the
+% screen
+dstRect = [0 0 visibleSize visibleSize];
+dstRect = CenterRect(dstRect, cfg.windowRect);
+
+% Calculate the wait duration
+waitDuration = waitframes * cfg.ifi;
+
+% Recompute pixPerCycle, this time without the ceil() operation from above.
+% Otherwise we will get wrong drift speed due to rounding errors
+pixPerCycle = 1 / freqCyclesPerPix;
+
+% Translate requested speed of the grating (in cycles per second) into
+% a shift value in "pixels per frame"
+shiftPerFrame = cyclesPerSecond * pixPerCycle * waitDuration;
+
+% Sync us to the vertical retrace
+vbl = Screen('Flip', cfg.window);
+
+% Set the frame counter to zero, we need this to 'drift' our grating
+frameCounter = 0;
+
+% Loop until a key is pressed
+while ~KbCheck
+
+    % Calculate the xoffset for our window through which to sample our
+    % grating
+    xoffset = mod(frameCounter * shiftPerFrame, pixPerCycle);
+
+    % Now increment the frame counter for the next loop
+    frameCounter = frameCounter + 1;
+
+    % Define our source rectangle for grating sampling
+    srcRect = [xoffset 0 xoffset + visibleSize visibleSize];
+
+    % Draw noise texture to the screen
+    Screen('DrawTexture', cfg.window, noiseTex, [], dstRect, []);
+
+    % Draw grating mask
+    Screen('DrawTexture', cfg.window, gratingMaskTex, srcRect, dstRect, []);
+
+    % Flip to the screen on the next vertical retrace
+    vbl = Screen('Flip', cfg.window, vbl + (waitframes - 0.5) * cfg.ifi);
+
+end
+
+
+    
+% -------------------------------------------------------------------------
+    
+
+devSandbox_cleanUp
+    
+catch
+    
+    devSandbox_cleanUp
+    psychrethrow(psychlasterror);
+    
+end
+
+
+end
+
+
+function cfg = devSandbox_initPTB(cfg)
+
+Screen('Preference', 'SkipSyncTests', 2);
+
+PsychDebugWindowConfiguration
+
+% Here we call some default settings for setting up Psychtoolbox
+PsychDefaultSetup(2);
+
+% Get the screen numbers
+cfg.screens = Screen('Screens');
+
+% Draw to the external screen if avaliable
+cfg.screenNumber = max(cfg.screens);
+
+% Open an on screen window
+[cfg.window, cfg.windowRect] = PsychImaging('OpenWindow', cfg.screenNumber, cfg.backgroundColor);
+
+% Get the size of the on screen window
+[cfg.screenXpixels, cfg.screenYpixels] = Screen('WindowSize', cfg.window);
+
+% Query the frame duration
+cfg.ifi = Screen('GetFlipInterval', cfg.window);
+
+% Get the centre coordinate of the window
+[cfg.xCenter, cfg.yCenter] = RectCenter(cfg.windowRect);
+
+% Set up alpha-blending for smooth (anti-aliased) lines
+Screen('BlendFunction', cfg.window, 'GL_SRC_ALPHA', 'GL_ONE_MINUS_SRC_ALPHA');
+
+end
+
+function devSandbox_cleanUp
+
+% A wrapper function to close all windows, ports, show mouse cursor, close keyboard queues
+% and give access back to the keyboards.
+
+WaitSecs(0.5);
+
+Priority(0);
+
+ListenChar(0);
+KbQueueRelease();
+
+ShowCursor
+
+% Screen Close All
+sca;
+
+% Close Psychportaudio if open
+if PsychPortAudio('GetOpenDeviceCount') ~= 0
+    PsychPortAudio('Close');
+end
+
+if ~ismac
+    % remove PsychDebugWindowConfiguration
+    clear Screen
+end
+
+close all
+
+
+end