function idum = plota(xx,icode)
global nb nv barras restric massa x0
global extforces totforces tensoes grav
global cvec

%% plota estado atual
xmin=xx(1);
xmax=xx(1);
ymin=xx(2);
ymax=xx(2);
for i=1:nb
	xyloc(1,1) = xx(2*barras(i,1)-1);
	xyloc(1,2) = xx(2*barras(i,1));
	xyloc(2,1) = xx(2*barras(i,2)-1);
	xyloc(2,2) = xx(2*barras(i,2));
        plot(xyloc(:,1),xyloc(:,2));
        hold on;
	xmin=min(xmin,min(xyloc(:,1)));
	xmax=max(xmax,max(xyloc(:,1)));
	ymin=min(ymin,min(xyloc(:,2)));
	ymax=max(ymax,max(xyloc(:,2)));
	xyloc(1,1) = x0(2*barras(i,1)-1);
	xyloc(1,2) = x0(2*barras(i,1));
	xyloc(2,1) = x0(2*barras(i,2)-1);
	xyloc(2,2) = x0(2*barras(i,2));
	xmin=min(xmin,min(xyloc(:,1)));
	xmax=max(xmax,max(xyloc(:,1)));
	ymin=min(ymin,min(xyloc(:,2)));
	ymax=max(ymax,max(xyloc(:,2)));
end
diam=max(xmax-xmin,ymax-ymin);
dd = diam/20;
axis([xmin-dd xmax+dd ymin-dd ymax+dd]);
%axis([-3 7 -1 9]);
%pause;
if (icode == 1) 
for i=1:nb
	xyloc(1,1) = x0(2*barras(i,1)-1);
	xyloc(1,2) = x0(2*barras(i,1));
	xyloc(2,1) = x0(2*barras(i,2)-1);
	xyloc(2,2) = x0(2*barras(i,2));
        plot(xyloc(:,1),xyloc(:,2),'r');
        hold on;
end
else if (icode == 2)
m = max(abs(totforces))
for i=1:nv
 k=[totforces(2*i-1),totforces(2*i)];
 k=cvec*k/m;
 k(1)=k(1)+xx(2*i-1);
 k(2)=k(2)+xx(2*i);

  plot( [xx(2*i-1) k(1)], [xx(2*i) k(2)], 'g')
  plot( [ k(1)], [ k(2)], 'go')

end
end
end