%---------------------------%
%                           %
%   Title:   Pajarita.doo   %
%   Author:  Jérôme Gout    %
%   Date:    14 May 2001    %
%                           %
%---------------------------%

% a macro to choose my color
\define \my_color { 
	100, 85, 72
}

% diagram header : 
% it contains all general information
\diagram_header { 
  \designer("Anonymous");
  \title("'Pajarita'");
  \diagrammer("Jerome Gout");
  \diagram_date(2001);
  \comment("'Pjarita' means small bird in spanish.");
  \comment("Original author of this model is unknown. I guess it comes from Spain.");
  \comment("Difficulty : Simple - Use a mono colored 15cm square sheet.");
  \bottom_margin(15);
  \vertical_space(10);
  \color_front(\my_color);
  \color_back(\my_color);
}

% drawing zone height (for all next steps)
\visible_area_height(60);

\step {
  \square(a,b,c,d);
  \fill(front, a, b ,c ,d);
  \valley_fold(a,c);
  \simple_arrow(d, b, valley, unfold, right);
  \valley_fold(b,d);
  \simple_arrow(c,a, valley, unfold, left);
  \caption("Mark diagonals.");
  o = \intersection([a,c], [b,d]);

}

\step {
  % useful points definition
  ab2 = \middle(a,b);
  bc2 = \middle(b,c);
  cd2 = \middle(c,d);
  da2 = \middle(d,a);

  [ab1, cd3] = \point_to_point(a, ab2, [a, b], [c,d]);
  \valley_fold(ab1, cd3, [a,c], [b,d]); % not all the line but just inside diagonals
  \simple_arrow(da2, o, valley, unfold, left);

  [ab3, cd1] = \point_to_point(b, ab2, [a, b], [c,d]);
  \valley_fold(ab3, cd1, [b,d], [a,c]); % not all the line but just inside diagonals
  \simple_arrow(bc2, o, valley, unfold, right);

  \caption("Make pinches inside both diagonals.");
}

\step {
  \fold(ab3, cd1, [b,d], [a,c]); % because there is still bugs ...
  \fold(ab1, cd3, [a,c], [b,d]); % because there is still bugs ...
  [da3, bc1] = \point_to_point(a, da2, [d,a], [b,c]);
  \valley_fold(bc1, da3, [b,d]);
  \simple_arrow(ab2, o, unfold, valley, right);

  [da1, bc3] = \point_to_point(d, da2, [d,a], [b,c]);
  \valley_fold(bc3, da1, [a,c]);
  \simple_arrow(cd2, o, unfold, valley, left);
}

\step {
  i1 = \intersection([ab3, cd1], [b,d]);
  i2 = \intersection([ab3, cd1], [a,c]);
  % cutting all edge at i1
  \cut([ab3, cd1], i1);
  \cut([b,d], i1);
  \cut([da3, bc1], i1);
  \hide([ab3, i1]);
  \hide([i1, bc1]);
  % same with i2, becareful [ab3, cd1] has been cut -> [i1, cd1]
  \cut([i1, cd1], i2);
  \cut([a,c], i2);
  \cut([da1, bc3], i2);
  \hide([i2, bc3]);
  \hide([i2, cd1]);

  % re-forming folds of the two last steps (with new points)
  \valley_fold(da3, i1);
  \valley_fold(i1, i2);
  \valley_fold(i2, da1);
  \simple_arrow(ab2, o, none, valley, right);
  \simple_arrow(cd2, o, none, valley, left);
  \valley_fold(i1, b);
  \valley_fold(i2, c);
  \mountain_fold(i1, bc2);
  \mountain_fold(i2, bc2);
  \simple_arrow(bc2, o, none, valley, right);
 
  % preparing moves of the next step
  \cut([a,d], da1);
  \cut([a, da1], da3);
  i3 = \inter_cut([d, i1], [da1, i2]);
  \cut([da1, i2], i3);
  \cut([ab1, cd3], i3);
  \hide([i3, cd3]);
  
  i4 = \inter_cut([a, i2], [da3, i1]);
  \cut([da3, i1], i4);
  \cut([ab1, i3], i4);
  \hide([i4, ab1]);

  \caption("Use existant folds made in last two steps");
  \caption("Make them concurrently");
}

% now we draw it bigger
\scale(130);

\step {
  % moves resulting of the three previous folds (left to right)
  \move(a, da2);
  \move(d, da2);
  \move(ab1, [i4, i1]);
  \move(cd3, [i2, i3]);
  % to move b on bc2 we have to cut b bc2 on its middle
  \cut([b,c], bc1);
  \move(b, bc2);
  \move(bc1, [i1, bc2]); % move temporary point also
  \move(bc2, o);
  \move(c, b); % it should be \move(c, bc2) but bc2 has moved
  \move(ab2, o);
  \move(cd2, o);

  % fill
  \unfill(a, b, c, d);
  \fill(back, da3, i1, b, i2, da1);

  % hide elements and redraw with correct line style borders
  \hide([i1, i2]);
  \hide([i3, i4]);
  \hide([i1, i3]);
  \hide([i2, i4]);
  \hide(bc2);
  \border(da3, i4);
  \border(i4, i1);
  \border(i1, b);
  \border(c, i2);
  \border(i2, i3);
  \border(i3, da1);

  % new folds --
  \valley_fold(ab2, i4);
  \mountain_fold(a, i4);
  \valley_fold(cd2, i3);
  \mountain_fold(d, i3);
  \xray_fold(i4, i3);

  % points that do not exist really
  i5 = \symmetry(ab2, [i4, i1]);
  i6 = \symmetry(cd2, [i2, i3]);

  \simple_arrow(a, i5, none, valley, left);
  \simple_arrow(d, i6, none, valley, right);
  \caption("Open each layer to top and bottom");
  \caption("Use also the hidden crease made in step 2,");
  \caption("We show it using an x-ray fold");

  % preparing next moves
  \cut([a,b], ab2);
  \cut([c,d], cd2);
}

\step {
  \move(a, i5);
  \move(da3, [i4, i3]);
  \move(da2, o);
  \move(d, i6);
  \move(da1, [i4, i3]);
  \hide([i4, ab2]);
  \hide([i3, cd2]);
  % some edges change
  \border(i4, a);
  \border(i4, i3);
  \border(i3, d);
  \fold(i4, da3);
  \fold(i3, da1); 
  \border(i4, i1, [a,da3]);
  \border(i3, i2, [d,da1]);

  % prepare the "pajarita" head
  \valley_fold(i4, da2);
  \simple_arrow(a, [i4, da2], unfold, valley, left);
  % fill
  \fill(back, i4, a, d, i3);
  \caption("Here is the result !");
  \caption("Fold unfold to make easier future fold");
  \caption("Turn over horizontally.");
}

\turn_over_vertical; 

\step{
  % restore the back layer to the top
  % be careful points have been moved by turn_over_vertical
  \border(i1, i4);
  \border(i2, i3);
  \border(ab2, a, [i1, i4]);
  \border(cd2, d, [i2, i3]);
  \hide([da1, da3]);
  \hide([i4, da2]);
  \border(i1, i2);
  \show([i1, i3]);
  \show([i4, i2]);
  \border(bc2, b, [i1, i2]);
  \border(ab2, b, [i1, i2]);
  \border(bc2, c, [i1, i2]);
  \border(cd2, c, [i1, i2]);
 
  % next fold - valley diagonal
  \valley_fold(i4, i2);
  \simple_arrow(i1, i3, none , valley, left, 50); 

  % preparing next moves
  \cut([i1, i3], o);

  \caption("Fold the model along the diagonal.");
}

\step{
  \unfill(da3, i1, b, i2, da1);
  \move(i1, i3);
  \move(b, d);
  \move(bc1, cd2);
  \hide([da3, i4]);
  \hide(i3); % to hide [i3, i2] and [i3, i4]
  \hide(o);
  \hide(da3);
  \cut([i2, i4], o); % [o, i4] and [o, i2] are still drawn because edges
                     % are created after we hide all edges containing o
  \space_fold([i2, o], 5, 5);  % change percent limit at o
  \space_fold([i4, o], 5, 5);  % change percent limit at o
  \border(i1, i2, [bc2, b]);

  % fill
  \fill(back, c, o, da1, i2);

  \valley_fold(i4, o);
  \simple_arrow(a, [i4, o], none, valley, right);
  \caption("Reverse fold the 'pajarita' head");
  \caption("Open model to reverse easily the fold.");
}

\rotate(45);

\step{
 \unfill(i4, a, d, i3);
 \move(a, [i4, o]);
 \move(da3, [i4, o]);

 \border(ab2, a);
 \border(i4, i1, [ab2, a]);
 \border(i4, o);

 \fill(back, i4, i1, b, ab2);
 \fill(front, i4, a, ab2);
 \caption("Finished model !");
}