initialize3Screen.m

function ScreenInfo = initializeScreen(WhichScreen)
% gets the screen info
% finds out the appropriate values for black, white, and gray
% ScreenInfo = initializeScreen(WhichScreen);
%
% ScreenInfo = initializeScreen() with no arguments returns a fictitious/typical screen info
%
AssertOpenGL;
InitializeMatlabOpenGL(1);

if nargin<1
   disp('Making a fictitious Screen structure');  % SK why do we need this?
   ScreenInfo.PixelSize  = 0.0609;
   ScreenInfo.Xmax       = 640;
   ScreenInfo.Ymax       = 480;
   ScreenInfo.FrameRate  = 124.8918;
   ScreenInfo.Dist       = 64;
   return
end

[ret, systemName] = system('hostname');



ScreenInfo.whiteIndex = WhiteIndex(WhichScreen);
ScreenInfo.blackIndex = BlackIndex(WhichScreen);
ScreenInfo.grayIndex = round((ScreenInfo.whiteIndex+ScreenInfo.blackIndex)/2);
% Make sure that on floating point framebuffers we still get a well defined gray
if ScreenInfo.grayIndex == ScreenInfo.whiteIndex
    ScreenInfo.grayIndex = ScreenInfo.whiteIndex / 2;
end

ScreenInfo.WhichScreen = WhichScreen;
%ScreenInfo.PixelDepth = 8; % SK: what is this used for?


Screen('CloseAll');
WaitSecs(0.5);


% the following line needs be enabled for proper linear superposition
%[windowPtr, ScreenRect] = Screen('OpenWindow', WhichScreen, [], [], ScreenInfo.PixelDepth, [], [], [], kPsychNeed16BPCFloat);
% SK [windowPtr, ScreenRect] = Screen('OpenWindow', WhichScreen, [], [], ScreenInfo.PixelDepth);
% SK Screen('BlendFunction', windowPtr, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); % needed for alpha blending (LB 071019)
% SK Screen('FillRect', windowPtr, gray); Screen('Flip', windowPtr);		% force gray screen

% Open a double buffered fullscreen window and set default background color to gray
% [ScreenInfo.windowPtr, ScreenInfo.screenRect]=Screen('OpenWindow', WhichScreen, ScreenInfo.grayIndex);
[ScreenInfo.windowPtr(1), ScreenInfo.screenRect(1,:)]=Screen('OpenWindow', WhichScreen, ScreenInfo.grayIndex, [0 0 750 600]);
% [ScreenInfo.windowPtr(2), ScreenInfo.screenRect(2,:)]=Screen('OpenWindow', WhichScreen, ScreenInfo.grayIndex, [750 0 1650 600]);
% [ScreenInfo.windowPtr(3), ScreenInfo.screenRect(3,:)]=Screen('OpenWindow', WhichScreen, ScreenInfo.grayIndex, [1650 0 2400 600]);

% Enable alpha blending
Screen('BlendFunction', ScreenInfo.windowPtr(1), GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

ScreenInfo.Xmax = RectWidth(ScreenInfo.screenRect(1,:));
ScreenInfo.Ymax = RectHeight(ScreenInfo.screenRect(1,:));
ScreenInfo.FrameRate = FrameRate(WhichScreen);

% make a linear Clut (do this even though you will do ltLoadCalibration later!!!)
Screen('LoadNormalizedGammaTable', WhichScreen, repmat( (0:255)', 1, 3)/255);

if ~isempty(strfind(systemName, 'zupervision'))
    ScreenInfo.MonitorType = 'SyncMaster 173s';
    ScreenInfo.MonitorSize = 34; % cm - horizontal
    ScreenInfo.CalibrationDir = 'C:\Calibrations\';    
else
	ScreenInfo.MonitorType = 'Unknown';
	ScreenInfo.MonitorSize = 1;
	ScreenInfo.CalibrationDir = 'C:\Calibrations\';
end

ScreenInfo.PixelSize = ScreenInfo.MonitorSize/ScreenInfo.Xmax; % size of pixel

disp(['You are using a ' ScreenInfo.MonitorType]);
disp(['The refresh rate is ' num2str(ScreenInfo.FrameRate,'%3.3f') ' Hz']);
fprintf('The resolution is %dx%d pixels.\n',ScreenInfo.Xmax, ScreenInfo.Ymax);