function cutter_demo
% egr106 project 2006
clc
clear

%% 2 demos
for demo = 1:2

    close all
    x1 = [ 1 2 3 2 ];
    y1 = [ 1 1 2 3 ];
    patch(x1,y1,'r')
    x2 = [ 4 5 5 3 ];
    y2 = [ 1 2 4 3 ];
    patch(x2,y2,'g')
    axis([0 6 0 5])
    grid on

    switch demo
        case 1
            pathx = [ x1, x1(1), x2(4), x2, 0 ];
            pathy = [ y1, x1(1), y2(4), y2, 0 ];
            type =  [ 0 1 1 1 1 0 1 1 1 1 0 ];
        case 2
            pathx = [ x1(1:3), x2(4), x2, x1(3:end), x1(1), 0 ];
            pathy = [ y1(1:3), y2(4), y2, y1(3:end), y1(1), 0 ];
            type =  [ 0 1 1 0 1 1 1 1 0 1 1 0 ];
    end

    egr106cutter(1,1,1,1)
    for k = 1:length(pathx)
        egr106cutter(pathx(k),pathy(k),type(k),0)
    end
    pause
    
end

%% cutting function

function egr106cutter(xnew,ynew,type,flag)
% function to simulate motion of the cutter
%       path is from current location to (xnew,ynew)
%       type specifies cutting (1) versus moving (0)
%       differences include speed and color
%       cutting and moving lengths since last reset are
%           shown in the title area
%       flag is normally 0; flag = 1 resets window
persistent x y cutlen movlen blobhandle titlehandle
if flag == 1    % reinitialize routine
    x = 0;
    y = 0;
    cutlen = 0;
    movlen = 0;
    hold on
    blobhandle = plot(0,0,'o','markersize',10,'markerfacecolor','k');
    titlehandle = title(['Cut length = ',num2str(0,4),...
        '; Move length = ',num2str(0,4)]);
else
    dist = sqrt((x-xnew)^2+(y-ynew)^2);
    if type == 1    % cutting
        n = ceil(20*dist);
        color = 'k';
    else            % moving
        n = ceil(5*dist);
        color = 'r';
    end
    hold on
    xv = linspace(x,xnew,n);
    yv = linspace(y,ynew,n);
    linehandle = plot(xv(1),yv(1),color,'linewidth',3);
    for k2 = 1:length(xv)
        set(blobhandle,'Xdata',xv(k2),'Ydata',yv(k2))
        set(linehandle,'Xdata',xv([1,k2]),'Ydata',yv([1,k2]))
        pause(.05)
        if type == 1
            cutlen = cutlen + dist/n;
        else
            movlen = movlen + dist/n;
        end
        set(titlehandle,'String',['Cut length = ',sprintf('%6.3f',cutlen),...
            '; Move length = ',sprintf('%6.3f',movlen)])
        drawnow
    end
    x = xnew;
    y = ynew;
end