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>
14 lines
549 B
Common Lisp
14 lines
549 B
Common Lisp
;; Scanlines effect - VHS-style horizontal line shifting
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;; @param amplitude float [0, 100] default 10
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;; @param frequency float [1, 100] default 10
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;; @param randomness float [0, 1] default 0.5
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(define-effect scanlines
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((amplitude 10) (frequency 10) (randomness 0.5))
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(map-rows frame
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(lambda (y row)
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(let* ((sine-shift (* amplitude (sin (/ (* y 6.28) (max 1 frequency)))))
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(rand-shift (random (- amplitude) amplitude))
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(shift (floor (lerp sine-shift rand-shift randomness))))
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(roll row shift 0)))))
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