% Calibration routine for SMI IViewX eyetracker and Psychtoolbox,
% using the serial port for communication.
% This function is fairly robust - if calibration fails for some
% reason it will quietly print out some warnings and return. If
% calibration failures are catastrophic for your experiment, you will
% need to check the output flag for success==1 in your own script.
% Syntax:
% success = calibrateEyeTracker(window,[ET_serial],[ET_params])
% Inputs (all optional except the Psychtoolbox window):
% window - Psychtoolbox screen handle
% ET_serial - Opened serial port object for scanner. Initialise with e.g.
% 		ET_serial = serial('COM1','BaudRate',9600,'Databits',8);
%   	fopen(ET_serial);
% 		If left undefined, we open a serial port with the above settings.
% ET_params - struct with eye tracking parameters. All are optional.
% 	npoints - (13) number of calibration points
% 	calibarea - ([screenx screeny]) calibration area on screen
% 	bgcolour - ([128 128 128]) background colour (RGB)
% 	targcolour - ([255 255 255]) target colour (RGB)
% 	targsize - (20) target height/width in pixels
% 	acceptkey - ([spacebar]) key for forcing point acceptance
% 	quitkey - ([escapekey]) key for aborting calibration
% 		Use KbName('UnifyKeyNames') to get names for other keys
%   waitforvalid - (1) wait for valid data during calibration
%   randompointorder - (0) randomise point order during calibration
%   autoaccept - (1) Auto-accept points after some fixation dur.
%   checklevel - (2) Fussiness when accepting points (0-3). SMI recommends
%       2 for every-day use. Drop if subject is problematic.
% 13/4/2010 J Carlin, heavily indebted to Maarten van Caasteren's
% VB script for E-Prime

% TODO
% Drift correction
% ET_SAV - no problem!

function [ready,points] = calibrateEyeTracker(window,ET_serial,ET_params)

% If no serial object entered, try to set one up
if ~exist('ET_serial','var') || isempty(ET_serial)
    ET_serial = serial('COM1','BaudRate',9600,'Databits',8);
    fopen(ET_serial);
end

% By default, calls time out in 10 SECONDS.
% This is clearly unacceptably slow for our
% purposes. Now 50 ms.
set(ET_serial,'timeout',.1);
% The downside is that Matlab spits out a lot of
% warnings. Let's disable these...
wstate=warning('off','MATLAB:serial:fgetl:unsuccessfulRead');




% If you don't know what you want, we will fill this in with
% defaults.
if ~exist('ET_params','var')
	ET_params = struct;
end

% Screen settings
sc = Screen('Resolution',window);
schw = [sc.width sc.height];

KbName('UnifyKeyNames');

% These are the default settings
default_params = struct(...
	'npoints',13,...
	'calibarea',schw,... % Full screen size
	'bgcolour',[128 128 128],...
	'targcolour',[255 255 255],...
	'targsize',20, ...
	'acceptkey',KbName('space'), ...
	'quitkey',KbName('escape'), ...
    'waitforvalid',1,...
    'randompointorder',0,...
    'autoaccept',1,...
    'checklevel',2 ...
	);

% Now put in defaults for whatever was left undefined
fns = fieldnames(default_params);
for fn = fns'
	if ~isfield(ET_params,fn{1})
		ET_params.(fn{1}) = default_params.(fn{1});
	end
end

% Quick sanity check
if ~sum(ET_params.npoints == [2,5,9,13])
    error('SMI eye trackers only support 2,5,9 or 13 point calibration')
end

% Start and stop calibration once. This somehow
% solves a lot of problems
fprintf(ET_serial,sprintf('ET_CAL %d',ET_params.npoints));
fprintf(ET_serial,'ET_BRK');
% Wait for various crap to go through
w = 0;
while w == 0
    if isempty(fgetl(ET_serial))
        w = 1;
    end
end

% Draw background
Screen(window,'FillRect',ET_params.bgcolour);

% Display settings for targets
% Make a cross - studiously avoiding alpha blending here to
% maximise compatibility (but you will need to im processing toolbox)
% Settings
cross_orgsize = 100;
cross_linewidth = .05;
% Build cross
cs = round((cross_orgsize / 2) - (cross_orgsize * cross_linewidth));
ce = round((cross_orgsize / 2) + (cross_orgsize * cross_linewidth));
cr = zeros(cross_orgsize);
cr(:,cs:ce) = 1;
cr(cs:ce,:) = 1;
% Resize - Since square, no point to bicubic interpolation
cr_rs = imresize(cr,[ET_params.targsize ET_params.targsize],'nearest');
% Make target uint8, colour
rgb_t = ET_params.targcolour;
cros = uint8(cat(3,cr_rs*rgb_t(1),cr_rs*rgb_t(2),cr_rs*rgb_t(3)));
% Make an appropriately-coloured background
rgb = ET_params.bgcolour;
bg = uint8(ones(ET_params.targsize));
bg_rgb =cat(3,bg*rgb(1),bg*rgb(2),bg*rgb(3));
% Put background and target together
target = bg_rgb;
target(find(cros)) = cros(find(cros));
% Draw texture
targetbuf = Screen('MakeTexture',window,target);
% Set up basic rect
targetrect = [0 0 size(target,1) size(target,2)];

% Various calibration settings
fprintf(ET_serial,sprintf('ET_CPA %d %d',0,ET_params.waitforvalid));
fprintf(ET_serial,sprintf('ET_CPA %d %d',1,ET_params.randompointorder));
fprintf(ET_serial,sprintf('ET_CPA %d %d',2,ET_params.autoaccept));
fprintf(ET_serial,sprintf('ET_LEV %d',ET_params.checklevel));

% Set calibration area (ie screen res)
fprintf(ET_serial,sprintf('ET_CSZ %d %d',schw(1),schw(2)));

% These are the default ET points for a 13 point calibration on
% a 1280x1024 screen. We can tweak this according to our needs...
standardpoints = [640 512;
    64 51;
    1216 51;
    64 973;
    1216 973;
    64 512;
    640 51;
    1216 512;
    640 973;
    352 282;
    928 282;
    352 743;
    928 743];

% Scale up/down to match calibration area
scaledpoints = standardpoints .* repmat(ET_params.calibarea ...
    ./ [1280 1024],13,1);

% If the calibration area doesn't match the screen res,
% need to shift everything to centre
shift = @(xy) round(xy + ([sc.width sc.height]/2) - (ET_params.calibarea/2));

% Shift the calibration points to centre on the screen
shiftedpoints = round(scaledpoints + repmat(schw/2,13,1) ...
    - repmat(ET_params.calibarea/2,13,1));

% Set to appropriate npoints
shiftedpoints = shiftedpoints(1:ET_params.npoints,:);

% Send custom points to eye tracker
for p = 1:length(shiftedpoints)
    fprintf(ET_serial,sprintf('ET_PNT %d %d %d',p, ...
        shiftedpoints(p,1),shiftedpoints(p,2)));
end
% Start calibration
fprintf(ET_serial,sprintf('ET_CAL %d',ET_params.npoints));

ready = 0;
ntries = 0;

% Point coordinates go here - just to validate
points = zeros(ET_params.npoints,2);

rc = 0;
while ~ready
	ntries = ntries+1;

	% If no connection with serial, return anyway
	if ntries > 5000
		fprintf('Serial port communication failure!\n')
		break
	end

	% Check for manual attempts to move things along
	[keyisdown, secs, keyCode] = KbCheck;
	if keyisdown
		k = find(keyCode);
		k = k(1);
		% Force acceptance of current point
		if k == ET_params.acceptkey
			fprintf('Accepting point...\n')
            %WaitSecs(.2); % Time to let go of key...
            % Now stop execution until the key is released
            while KbCheck
                WaitSecs(.01);
            end
            fprintf(ET_serial,'ET_ACC');
		% Give up on calibration
		elseif k == ET_params.quitkey
			fprintf('Calibration attempt aborted!\n')
			fprintf(ET_serial,'ET_BRK');
			break
		end
	end

	% Check if the eye tracker has something to say
    response = fgetl(ET_serial);
    
	% What might the eye tracker have to say?
	if ~isempty(response)
		% Save each response - mainly for debugging
		rc = rc+1;
        resplog{rc} = response;
		% Split by spaces
		command_etc = strread(regexprep(response,' ',' '),'%s');
		command = command_etc{1};

		%%% What we do next depends on the command we got:
		% Calibration point change
        if strcmp(command,'ET_CHG')
            % Coordinates for point
            xy = points(str2num(command_etc{2}),:);
			% Rect for point
			pointrect = CenterRectOnPoint(targetrect,xy(1),xy(2));
			% Draw into rect
			Screen('DrawTexture',window,targetbuf,[],pointrect);
            Screen(window,'Flip');
            % Reset timeout counter
            ntries = 0;

            % Calibation point definition
        elseif strcmp(command,'ET_PNT')
            points(str2num(command_etc{2}),:) = ...
				[str2num(command_etc{3}) str2num(command_etc{4})];

		% Screen size verification
		%elseif strcmp(command,'ET_CSZ')
		% Actually, we don't want calibration area
			% to match screen size.
			% So arguments are X and Y size
			%sc = Screen('Resolution',window);
			%if str2num(command_etc{2}) ~= sc.width
				%fprintf('Calibration failed - Screen width mismatch\n')
				%break
			%elseif str2num(command_etc{3}) ~= sc.height
				%fprintf('Calibration failed - Screen height mismatch\n')
				%break
			%end

		% Calibration finished
		elseif strcmp(command,'ET_FIN')
			ready = 1;
        
        % Various commands we don't care about
        elseif strcmp(command,'ET_REC') || ...
                strcmp(command,'ET_CLR') || ...
                strcmp(command,'ET_CAL') || ...
                strcmp(command,'ET_CSZ') || ...
                strcmp(command,'ET_ACC') || ...
                strcmp(command,'ET_CPA') || ...
                strcmp(command,'ET_LEV')
            continue

		% Catch all
		else
			fprintf(sprintf(['Calibration failed - received unrecognised '...
				'input: %s\n'],response));
            fprintf(ET_serial,'ET_BRK');
			break % DEBUG
		end % Resp interpretation
	end % Resp check
end % While

% Clear the target texture from memory
Screen('Close',targetbuf);
% Return warning state to whatever it started as
warning(wstate.state,wstate.identifier);