PsychSetupParams.m

function params = PsychSetupParams(bkgroundColor, doAlphaBlending,doMultiSample)
%sets up some normal values used in experiments such as a gray background
%and Arial font, and a large text size, etc...
%saves all relevant screen info to the 'params' structure so that the
%entire structure can be passed in and out of functions, rather than
%zillions of variables. Also makes it expandable. 
%
% History:
% 29-May-2015   tjh     made initial version of the function 

global psych_default_colormode;
%make params structure
params = struct;
%set some defualt, common colors
params.colors.white = [1 1 1];
params.colors.black = [0 0 0];
params.colors.gray = [0.5 0.5 0.5];
params.colors.red = [1 0 0];
params.colors.green = [0 1 0];
%check if using normalized color values or not
if psych_default_colormode == 0
    params.colors.white = [255 255 255];
    params.colors.gray = [128 128 128];
end
%choose max screen number (will be the external monitor if connected)
params.screen = max(Screen('Screens'));
params.font = 'Arial'; %set the global font for PTB to use
params.tsize = 48; %set text size
params.TextColor = [params.colors.black]; %set global text color
%set the background color of the screen (defaults to gray)
if isempty(bkgroundColor)
    params.background = params.colors.gray;
else
    params.background = bkgroundColor;
end
params.multiSample = [];
if doMultiSample
    params.multiSample = 4;%set to a value greater than 0 if you want super sampling
end
%open the PTB window 
[params.win, params.rect] = PsychImaging('OpenWindow', params.screen, params.background,[],32,2,[],params.multiSample,kPsychNeed32BPCFloat);
%get screen width and height
[params.maxXpixels, params.maxYpixels] = Screen('WindowSize', params.win);
if doAlphaBlending
    %Set blend function for alpha blending
    Screen('BlendFunction', params.win, 'GL_SRC_ALPHA', 'GL_ONE_MINUS_SRC_ALPHA');
end
%find center of screen
[params.Xc,params.Yc] = RectCenter([0 0 params.maxXpixels params.maxYpixels]);
%now that the window pointer exists, set some values from earlier
Screen('TextSize', params.win, params.tsize);
Screen('TextFont',params.win, params.font);
Screen('TextSize',params.win, params.tsize);
Screen('TextStyle', params.win, 1);

%Maximum priority level
params.topPriorityLevel = MaxPriority(params.win);
Priority(params.topPriorityLevel);
%Query the frame duration
params.ifi = Screen('GetFlipInterval', params.win);