%@AUTEUR:Guillaume Connan
prologues:=2;

input courbes;
input geo;

color vert_e, turquoise, orange, vert_fonce, rose, vert_mer, bleu_ciel, or, rouge_v,bleu_m,bleu,bleu_f;
vert_e:=(0,0.790002,0.340007);
turquoise:=(0.250999,0.878399,0.815699);
orange:=(0.589999,0.269997,0.080004);
vert_fonce:=(0,1.4*0.392193,0);
rose:=(1.0, 0.752907, 0.796106);
bleu_ciel:=(1.2*0.529405,1.2*0.807794,1);%.2*0.921598);
or:=(1,0.843104,0);
rouge_v:=(0.829997,0.099994,0.119999);
bleu_m:=(0.7*0.529405,0.7*0.807794,0.7);%*0.921598);
bleu_f:=(0.211762,0.3231176,0.3686392);
bleu:=(0.529405,0.807794,1);

%  Figure mouette

beginfig(1)

% Déclarations des constantes %
  numeric xmin, xmax, ymin, ymax, N;

  ux:=2.7cm;
  uy:=1.75cm;
  xmin := -0.8; xmax := 1.4;
  ymin := -.5; ymax := 1.5;
  
% Définitions des axes et labels associés
  vardef axes =
    drawarrow (ux*xmin,0) -- (ux*xmax,0) ; % axe des x
    drawarrow (0,uy*ymin) -- (0,uy*ymax) ; % axe des y
    label.lrt(btex $x$ etex,(xmax*ux,0)); % label de l'axe des x
    label.urt(btex $y$ etex,(0,ymax*uy)); % label de l'axe des y
  enddef;
  
% Fonction
  vardef f(expr x) =abs(x*(x-2)) enddef;
  
  vardef trace (suffix g)(expr a,b,inc) =
    save i; numeric i;
    for i=a step inc until b:
      (i*ux,f(i)*uy) ..
    endfor (b*ux,f(b)*uy)
  enddef;
  
  axes; label.llft(btex $0$ etex,(-.05*ux,-.15*uy));

% Courbe
  
  draw trace(f,-.5,1.3,.01)withpen pencircle scaled 1.3bp withcolor bleu_m;
  
% Labels

  pair h,b,g,d;
  
  h:=(0,.1*uy); b:=(0,-.1*uy); g:=(-.1*ux,0); d:=(.1*ux,0);
  
  draw ((ux,0) shifted h)--((ux,0) shifted b);
  
  label.bot(btex $1$ etex,(ux,0) shifted b);
  
  label.ulft(btex $1$ etex,(0,uy) shifted h+.5g);
  
  label.urt(btex $y=\vert x(x-2)\vert$ etex,(1.3*ux,1*uy)); 
  
  drawarrow (0,0)--(0.5*ux,1*uy) dashed evenly withcolor bleu_f;
  drawarrow (0,0)--(-0.5*ux,1*uy) dashed evenly withcolor bleu_f;
  
endfig;
end