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Plasma effect: Difference between revisions
Added Common Lisp plasma demo with two different render functions
Thundergnat (talk | contribs) (→{{header|Perl 6}}: Add Perl 6 example) |
(Added Common Lisp plasma demo with two different render functions) |
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</lang>
=={{header|Common Lisp}}==
{{libheader|lispbuilder-sdl}}
{{libheader|simple-rgb}}
plasma_demo.lisp:
<lang lisp>(require :lispbuilder-sdl)
(require :simple-rgb)
(defparameter *palette*
(let ((palette-aux (make-array 256 :element-type 'fixnum)))
(dotimes (i 256)
(let ((color_i (simple-rgb:hsv->rgb (simple-rgb:hsv (/ i 255.0) 1.0 1.0))))
(setf (aref palette-aux i) (loop :for component :across color_i
:for i :from 0
:sum (ash component (* 8 i))))))
palette-aux)
"palette")
(defun value->color (palette palette-shift index)
(aref palette (mod (+ index palette-shift) (length palette))))
(defun return-color-by-pos (x y &optional w h)
"returns a color index"
(floor
(/ (+ (+ 128.0 (* 128.0 (sin (/ x 16.0))))
(+ 128.0 (* 128.0 (sin (/ y 8.0))))
(+ 128.0 (* 128.0 (sin (/ (+ x y) 16.0))))
(+ 128.0 (* 128.0 (sin (/ (sqrt (+ (* x x) (* y y))) 8.0)))))
4.0)))
(defun return-color-by-pos-another (x y &optional w h)
"a different function that returns a color index"
(floor
(/ (+ (+ 128.0 (* 128.0 (sin (/ x 16.0))))
(+ 128.0 (* 128.0 (sin (/ y 32.0))))
(+ 128.0 (* 128.0 (sin (/ (sqrt (+ (expt (/ (- x w) 2.0) 2) (expt (/ (- y h) 2.0) 2))) 8.0))))
(+ 128.0 (* 128.0 (sin (/ (sqrt (+ (* x x) (* y y))) 8.0)))))
4.0)))
(defun plasma-render (surface palette-shift)
"render plasma"
(let ((width (sdl:width surface))
(height (sdl:height surface)))
(sdl-base::with-pixel (s (sdl:fp surface))
(dotimes (h height)
(dotimes (w width)
(sdl-base::write-pixel s w h (value->color *palette* palette-shift (funcall #'return-color-by-pos-another w h width height)))))))
surface)
(defun demo/plasma ()
"main function: shows a window rendering a plasma efect"
(sdl:with-init ()
(let ((win (sdl:window 320 240
:bpp 24
:resizable nil
:title-caption "demo/plasma"
:icon-caption "demo/plasma")))
(let ((palette-shift 0))
(sdl:update-display win)
(sdl:with-events ()
(:idle
(plasma-render win palette-shift)
(sdl:update-display win)
(incf palette-shift))
(:video-expose-event () (sdl:update-display win))
(:key-down-event (:key key)
(when (or
(sdl:key= key :sdl-key-escape)
(sdl:key= key :sdl-key-q))
(sdl:push-quit-event)))
(:quit-event () t))))))
(demo/plasma)</lang>
=={{header|J}}==
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