factor/examples/dejong.factor

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1.4 KiB
Factor

! DeJong attractor renderer.
!
! To run this code, bootstrap Factor like so:
!
! ./f boot.image.le32
! -libraries:sdl:name=libSDL.so
! -libraries:sdl-gfx:name=libSDL_gfx.so
!
! (But all on one line)
!
! Then, start Factor as usual (./f factor.image) and enter this
! at the listener:
!
! "examples/dejong.factor" run-file
! For details on DeJong attractors, see
! http://www.complexification.net/gallery/machines/peterdejong/
IN: dejong
USE: sdl
USE: sdl-event
USE: sdl-gfx
USE: sdl-video
USE: namespaces
USE: math
USE: kernel
USE: test
USE: compiler
SYMBOL: a
SYMBOL: b
SYMBOL: c
SYMBOL: d
: next-x ( x y -- x ) a get * sin swap b get * cos - ;
: next-y ( x y -- y ) swap c get * sin swap d get * cos - ;
: pixel ( #{ x y }# color -- )
>r >r surface get r> >rect r> pixelColor ;
: iterate-dejong ( x y -- x y )
2dup next-y >r next-x r> ;
: scale-dejong ( x y -- x y )
swap width get 4 / * width get 2 / + >fixnum
swap height get 4 / * height get 2 / + >fixnum ;
: draw-dejong ( x0 y0 iterations -- )
[
iterate-dejong 2dup scale-dejong rect> white rgb pixel
] times 2drop ; compiled
: dejong ( -- )
! Fiddle with these four values!
1.0 a set
-1.3 b set
0.8 c set
-2.1 d set
1024 768 0 SDL_HWSURFACE [
[ 0 0 200000 [ draw-dejong ] time ] with-surface
<event> event-loop
SDL_Quit
] with-screen ;
dejong