Viznut is a demoscene artist who found the following bitart pattern that looks like birds flying rightward, the pattern can be seen in the Permacomputing Aesthetics paper:

abs(((x + y) & (x - y)) % 24) > 9

Uxntal

@viznut ( -> )
	( theme ) #0f08 DEOk INC INC DEOk INC INC DEO
	( viewp ) #0100 #22 DEO2k INC INC DEO2
	#0000
	&>x ( -- )
		DUP #29 DEO
		#0000
		&>y ( -- )
			DUP #2b DEO
			( x y + ) ADD2k STH2
			( x y - ) SUB2k STH2r
			( &24 % ) AND2 #0018 DIV2k MUL2 SUB2
			( 9 > ) #0009 GTH2 #2e DEO
			INC2 DUP ?&>y
		POP2 INC2 DUP ?&>x
	POP2 BRK

Factor

USING: accessors byte-vectors images images.viewer kernel math
ranges sequences sequences.deep ;
IN: capital.viznut

: bitbash ( -- bits )
    256 [1..b] dup [ 
        swap [ + ] [ - ] 2bi bitand 24 mod abs 9 > 255 0 ? 
    ] cartesian-map flatten >byte-vector ;

: viznut ( -- image )
    <image>
        { 256 256 }      >>dim
        bitbash          >>bitmap
        L                >>component-order
        ubyte-components >>component-type ;

! Run inside the listener:
viznut image.

fy

:N 256;
:rem dup2 / * -;
:idx2 over2 nip over;
( ppm header )
'P .c '1 .c .nl
N . N .
( pixels )
N [
    N [ idx2
        N !- swap N !-
        dup2 + swap rot swap - &
        24 rem 9 >
        \'0 \'1 ifte .c ] dotimes
  ] dotimes

konilo

* crc:drawing
* formula-art

:birds                                                          
  [ xy n:add xy n:sub and #24 n:mod n:abs #9 gt? ]              
  draw:with-formula ;                                         

birds