( forget new
: new ; )
off printload 

2 block n
2 n !
( 2 ' n 3 + @ b!)

512 const h0
7 const maxcolr
2 block colr
2 block ii
2 block hh
2 block x
2 block y
2 block x00
2 block y00
2 block mag

: incx x @ hh @ + x ! ;
: decx x @ hh @ - x ! ;
: dec2x x @ hh @ 2 * - x ! ;
: inc2x x @ hh @ 2 * + x ! ;
: incy y @ hh @ + y ! ;
: decy y @ hh @ - y ! ;
: dec2y y @ hh @ 2 * - y ! ;
: inc2y y @ hh @ 2 * + y ! ;
: plot x @ y @ colr @ dline ;
: hplot x @ 2 / y @ 2 / colr @ dline ;
: setplot x @ y @ 0 dline ;
: hsetplot x @ 2 / y @ 2 / 0 dline ;

: aa0 ;
: bb0 ;
: cc0 ;
: dd0 ;

: AA dup 0> if
     1- DD0 decx plot 
     1- recurse decy plot     
     1- recurse incx plot
     1- BB0 then 1+ ;

: BB dup 0> if
     1- CC0 incy plot 
     1- recurse incx plot     
     1- recurse decy plot
     1- AA0 then 1+ ;

: CC dup 0> if
     1- BB0 incx plot 
     1- recurse incy plot     
     1- recurse decx plot
     1- DD0 then 1+ ;

: DD1 dup 0> if
     1- AA0 decy plot 
     1- recurse decx plot     
     1- recurse incy plot
     1- CC0 then 1+ ;

link aa0 aa link bb0 bb      link cc0 cc   link dd0 dd1

: swcolr
       colr @ 1+ maxcolr /mod drop dup 0= if 1+ then colr ! ;

: hilb 0 colr !

      egam depth case 0 of 1 mag ! 2 n ! endof
                        1 of 1 mag ! n ! endof
                        2 of mag ! n ! endof endcase 

     0 ii !  h0 hh !  hh @ 2 / 19 * dup 5 / x00 !  5 / y00 ! 
 h0 2 / mag @ * hh !
    begin  swcolr
       ii @ 1+ ii !  
       hh @ 2 / hh ! 
	x00 @ hh @ 2 / + x00 !
        y00 @ hh @ 2 / + y00 !
       x00 @ x !  y00 @ y ! setplot 
	ii @ AA drop
    n @ ii @ - 0= end ;

: aaa0 ;
: bbb0 ;
: ccc0 ;
: ddd0 ;

: AAA dup 0> if
     1- recurse incx decy hplot 
     1- BBB0 inc2x hplot     
     1- DDD0 incx incy hplot
     1- recurse then 1+ ;

: BBB dup 0> if
     1- recurse decx decy hplot 
     1- CCC0 dec2y hplot     
     1- AAA0 incx decy hplot
     1- recurse then 1+ ;

: CCC dup 0> if
     1- recurse decx incy hplot 
     1- DDD0 dec2x hplot     
     1- BBB0 decx decy hplot
     1- recurse then 1+ ;

: DDD1 dup 0> if
     1- recurse incx incy hplot 
     1- AAA0 inc2y hplot     
     1- CCC0 decx incy hplot
     1- recurse then 1+ ;

link aaa0 aaa link bbb0 bbb      link ccc0 ccc   link ddd0 ddd1

: sierp 0 colr !
       egam depth case 0 of 1 mag ! 2 n ! endof
                        1 of 1 mag ! n ! endof
                        2 of mag ! n ! endof endcase 

     0 ii !  h0 8 / hh !  hh @ 19 * dup 4 / 140h + x00 !  5 / afh + y00 ! 
h0 4 ( 8 ) / mag @ * hh !
    begin  swcolr
       ii @ 1+ ii !   x00 @ hh @ - x00 !  
       hh @ 2 / hh !  y00 @ hh @ + y00 !
       x00 @ x !  y00 @ y !  hsetplot 
       ii @ AAA incx decy hplot drop
       ii @ BBB decx decy hplot drop 
       ii @ CCC decx incy hplot drop
       ii @ DDD1 incx incy hplot drop

    n @ ii @ - 0= end ;