function voidbk = lsaltofilmx(varargin)
voidbk = 0;
%lsalto : Salto Mortale rueckwarts des "L"
L = [4 4 4.8; 0.3 -1.3 -1.3; 1 1 1];
  PT = [ 1.3 0 0; 0 1.3 -7 ; 0 0 1 ];
lhand = plothclin(PT*L);
hold on
hdtx1 = text(-9.3,8.8,'Homogene Koordinaten-', ...
    'FontUnits','points','FontSize',18 , ...
   'Fontweight','demi');
hdtx2 = text(-9.3,7.3,'Transformationen des "L"', ...
    'FontUnits','points','FontSize',18 , ...
   'Fontweight','demi');
%axis([-10 10 -10 10]); axis square
%axis([-6.5 6.5 -1.5 11.5]);
%axis square; axis off;
hdbas=plot([-6.5 6.5]*1.3,[-1.4 -1.4]*1.3-7); pause(0.2)
hold on
npt = 120;
B = [ 1 0 -4; 0 1 0 ; 0 0 1]*L;
dw = pi/npt;
%
a = 4;
b = 8;
%
for k = 1:npt
  w = k*dw;
  wori = (atan2(b*cos(w),-a*sin(w)) -pi/2)*2;
  wori*180/pi;
  T = [cos(2*wori) -sin(2*wori) a*cos(k*dw); ...
       sin(2*wori) cos(2*wori) b*sin(k*dw); ...
      0 0 1];
  Lt = PT*T*B;
  pause(0.05);
   delete(lhand)
  lhand = plothclin(Lt);
end
  pause(0.9);
delete(lhand);
delete(hdbas);
delete(hdtx1);
delete(hdtx2);

% plothandle = plothclin(Lmat,colorstring)
% Plot einer Linie aus einer Matrix von Spaltenvektoren
%   in 2D homogenen Koordinaten
function plothandle = plothclin(lmat,colorstring)
if exist('colorstring') == 0  
  col = 'k';
else 
  col = colorstring;
end
plothandle = plot(lmat(1,:),lmat(2,:),col,'LineWidth',2);


