Drawing with mouse while recording the movement

Hello everyone.

I'm trying to make a signature recording program. It should be able to draw lines with mouse/pen tablet while also recording the movement (mouse position in axes) in real time.

I have modified mouseinput_timeout file to be able to record multiple lines.

%to call: out = mouseinput_timeout(timeoutval)
function selectedPts = mouseinput_timeout(timeoutval, axesHandle)

startTime = tic; %time start
a = 0;

if ~exist('axesHandle', 'var')
    axesHandle = gca;
end
if ~exist('timeoutval', 'var') 
    timeoutval = inf;
end
if ~(ishandle(axesHandle) && strcmp(get(axesHandle,'type'),'axes'))
    error('Axis handle is not valid');
end
if ~(isscalar(timeoutval) && (timeoutval > 0))
    error('Timeout should be a positive scalar');
end

figHandle = get(axesHandle, 'parent');
selectedPts = [];

oldProperties = get(figHandle, ...
    {'WindowButtonDownFcn','WindowButtonUpFcn',...
     'WindowButtonMotionFcn', 'units','pointer'});

set(figHandle, ...
    {'WindowButtonDownFcn','WindowButtonUpFcn',...
     'WindowButtonMotionFcn','units','pointer'}, ...
    { @buttonDownCallback, @buttonUpCallback, ...
      [], 'pixels', 'crosshair'}); 
figLocation = get(figHandle, 'Position'); 

if isinf(timeoutval)
    uiwait(figHandle);
else
    uiwait(figHandle, timeoutval);
end

set(figHandle, ...
    {'WindowButtonDownFcn','WindowButtonUpFcn',...
     'WindowButtonMotionFcn', 'units','pointer'}, ...
     oldProperties);

    function buttonMotionCallback(obj, eventdata) %#ok<INUSD>
        pt = mapCurrentPosition();
        selectedPts(end+1,:) = [pt(1,1:2) toc(startTime)];
    end

    function buttonStopCallback(obj, eventdata) %#ok<INUSD>
        selectedPts(end+1,:) = [0 0 toc(startTime)];
    end

    function buttonDownCallback(obj, eventdata) %#ok<INUSD>
        a = a+1;
        if a == 1
            selectedPts = [];
            set(obj, 'WindowButtonMotionFcn', @buttonMotionCallback);
        else
            set(obj, 'WindowButtonMotionFcn', @buttonMotionCallback);
        end
    end

    function buttonUpCallback(obj, eventdata) %#ok<INUSD>
        set(obj, 'WindowButtonMotionFcn', @buttonStopCallback);
    end

    function pt = mapCurrentPosition()
        scrn_pt = get(0, 'PointerLocation');              
        set(figHandle,'CurrentPoint',...
            [scrn_pt(1) - figLocation(1) + 1, ...
             scrn_pt(2) - figLocation(2) + 1]);
        pt = get(axesHandle,'CurrentPoint');       
    end
end

However I'm still stuck with trying to make the program able to draw actual lines on the axes. Some of my attempt were combining it with mlPaint.m or this sketch function, but I haven't succeeded yet.

Thank you in advance.