406cc7c0c7
Add S-expression based video effects pipeline with modular effect definitions, constructs, and recipe files. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
22 lines
711 B
Common Lisp
22 lines
711 B
Common Lisp
;; Vignette effect - darkens corners
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;; @param strength float [0, 1] default 0.5
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;; @param radius float [0.5, 2] default 1
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(define-effect vignette
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((strength 0.5) (radius 1))
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(let* ((w (width frame))
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(h (height frame))
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(cx (/ w 2))
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(cy (/ h 2))
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(max-dist (* (sqrt (+ (* cx cx) (* cy cy))) radius)))
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(map-pixels frame
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(lambda (x y c)
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(let* ((dx (- x cx))
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(dy (- y cy))
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(dist (sqrt (+ (* dx dx) (* dy dy))))
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(factor (- 1 (* (/ dist max-dist) strength)))
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(factor (clamp factor 0 1)))
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(rgb (* (red c) factor)
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(* (green c) factor)
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(* (blue c) factor)))))))
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