Présentation de 3D_01a.jps

-2 16 setxrange
-3.5 14.5 setyrange
/l 8 def

/a {0 l l} def    /f {l l 0} def    /m {0 3 l} def 
/b {l l l} def 	  /g {l 0 0} def    /n {4 0 l} def 
/c {l 0 l} def 	  /h {0 0 0} def    /p {0 0 5} def 
/e {0 l 0} def 

/I {-15 cos -15 sin} def
/J {35 cos 35 sin .8 mulv} def
/K {0 1} def

/xyz2xy {
3 dict begin
   /z exch def
   /y exch def
   /x exch def
   I x mulv
   J y mulv
   K z mulv
   addv addv
end
} def

[/A /B /C /E /F /G /H /M /N /P] 
[a b c e f g h m n p] {xyz2xy} capply
mapnp

P N C paral 
P H interdroite /C1 defpoint

P M C1 paral
A M interdroite /C2 defpoint

.7 setlinewidth
/fillstyle {.8 setgray fill} def
[C C1 C2 C] polygone*
1 setlinewidth

[M A B C G F B] ligne
[C N M P N] ligne
[P H G] ligne

gsave
   pointilles
   [A E H] ligne
   [E F] ligne
grestore

12 setfontsize
setTimesItalic
   (A) A ultext      (F) F brtext      (P) P cltext
   (B) B urtext	     (G) G drtext      (M) M ultext
   (C) C drtext	     (H) H bltext      (N) N urtext
   (E) E ultext