factor/contrib/mandel.factor

41 lines
993 B
Factor

! Based on lisp code from newsgroup discussion in
! comp.lang.lisp
! (loop for y from -1 to 1.1 by 0.1 do
! (loop for x from -2 to 1 by 0.04 do
! (let* ((c 126)
! (z (complex x y))
! (a z))
! (loop while (< (abs
! (setq z (+ (* z z) a)))
! 2)
! while (> (decf c) 32))
! (princ (code-char c))))
! (format t "~%"))
USE: combinators
USE: math
USE: prettyprint
USE: stack
USE: stdio
USE: strings
: ?mandel-step ( a z c -- a z c ? )
>r dupd sq + dup abs 2 < [
r> pred dup CHAR: \s >
] [
r> f
] ifte ;
: mandel-step ( a z c -- )
[ ?mandel-step ] [ ] while >char write 2drop ;
: mandel-x ( x y -- )
rect> dup CHAR: ~ mandel-step ;
: mandel-y ( y -- )
150 [ dupd 50 / 2 - >float swap mandel-x ] times* drop ;
: mandel ( -- )
42 [ 20 / 1 - >float mandel-y terpri ] times* ;