Image noise: Difference between revisions

=={{header|Common Lisp}}==

{{libheader|lispbuilder-sdl}}

noise_sdl.lisp:

<lang lisp>;; (require :lispbuilder-sdl)

(defun draw-noise (surface)

"draws noise on the surface. Returns the surface"

(let ((width (sdl:width surface))

(height (sdl:height surface))

(i-white (sdl:map-color sdl:*white* surface))

(i-black (sdl:map-color sdl:*black* surface)))

(sdl-base::with-pixel (s (sdl:fp surface))

(dotimes (h height)

(dotimes (w width)

;;(sdl:draw-pixel-* w h :surface s :color (if (zerop (random 2)) sdl:*white* sdl:*black*)))))

(sdl-base::write-pixel s w h (if (zerop (random 2))

i-white i-black ))))))

surface)

(defun draw-fps (surface)

"draws fps text-info on surface. Returns surface"

(sdl:with-surface (s surface)

(sdl:draw-string-solid-* (format nil "FPS: ~,3f" (sdl:average-fps))

20 20 :surface s :color sdl:*magenta*)))

(defun main ()

"main function, creates initializes the library and creates de display window"

(setf *random-state* (make-random-state))

(sdl:with-init (SDL:SDL-INIT-VIDEO SDL:SDL-INIT-TIMER)

(let ((main-window (sdl:window 320 240

:title-caption "noise_sdl.lisp"

:bpp 8

:flags (logior SDL:SDL-DOUBLEBUF SDL:SDL-HW-SURFACE)

:fps (make-instance 'sdl:fps-unlocked))))

(sdl:initialise-default-font)

(sdl:with-events ()

(:idle ()

(sdl:update-display (draw-fps (draw-noise main-window))))

(:video-expose-event ()

(sdl:update-display))

(:quit-event () T)))))

(main)

</lang>