function refreshtracker( varargin)
%refreshtracker( varargin)
%clears the tracker screen and displays all control windows
%varargin: 1 to update values, enter nothing to refresh the screen

persistent HArray
global Par

if nargin > 0 && varargin{1} == 1
    cla
    WIN = Par.WIN;
    nmW = size(WIN,2);
    HArray = zeros(nmW+3,1);
    ZM = Par.ZOOM;
    
    fix.x = cos((1:61)/30*pi);
    fix.y = sin((1:61)/30*pi);
    
    if Par.Bsqr
        dot.x = [-1 1 1 -1 -1];
        dot.y = [-1 -1 1 1 -1];
    else
        dot.x = cos((1:61)/30*pi);
        dot.y = sin((1:61)/30*pi);
    end
    
    % Screen rectangle
    HArray(1) = line('XData', [-Par.HW Par.HW Par.HW -Par.HW -Par.HW]*ZM, ...
        'YData', [-Par.HH -Par.HH Par.HH Par.HH -Par.HH]*ZM);
    if strcmp(Par.tracker_version, 'tracker_dark')
        set(HArray(1), 'Color','w'); % make screen border lines white
    end
    
    % Fix dot
    HArray(2) = line('XData', WIN(1,1)*ZM, 'YData', WIN(2,1)*ZM);
    set(HArray(2), 'Marker', 'o', 'MarkerSize', 5*ZM, 'MarkerFaceColor', 'r')
    
    for i = 1:nmW
        if (WIN(5,i) == 0) %fix window
            HArray(4+i) = line('XData', (fix.x*WIN(3,i)*0.5+WIN(1,i))*ZM,...
                'YData', (fix.y*WIN(4,i)*0.5+WIN(2,i))*ZM);
            if strcmp(Par.tracker_version, 'tracker_dark')
                set(HArray(4+i), 'Color', 'w');
            end
            HArray(3) = line('XData', (fix.x*WIN(3,i)*0.5*sqrt(0.5)+WIN(1,i))*ZM,...
                'YData', (fix.y*WIN(4,i)*0.5*sqrt(0.5)+WIN(2,i))*ZM);
            set(HArray(3), 'Color', [0.7 0.7 0.7])
            if strcmp(Par.tracker_version, 'tracker_dark')
                set(HArray(3), 'Color', [0.5 0.5 0.5])
            end
        elseif(WIN(5,i) == 2) %2 == correct target window
            HArray(4) = line('XData', (dot.x*WIN(3,i)*0.5+WIN(1,i))*ZM, 'YData', (dot.y*WIN(4,i)*0.5+WIN(2,i))*ZM);
            set(HArray(4), 'Color', 'm')
        else
            HArray(4+i) = line('XData', (dot.x*WIN(3,i)*0.5+WIN(1,i))*ZM, 'YData', (dot.y*WIN(4,i)*0.5+WIN(2,i))*ZM);
            if strcmp(Par.tracker_version, 'tracker_dark')
                set(HArray(4+i), 'Color', 'w');
            end
        end
    end
    
elseif varargin{1} == 2
    set(HArray(4), 'Color', 'g')
    
elseif varargin{1} == 3
    set(HArray(2), 'MarkerFaceColor', 'g')
else
    if ~isempty(HArray)
        cla( HArray )
    end
end