16 lines
574 B
Common Lisp
16 lines
574 B
Common Lisp
;; Scanlines effect - VHS-style horizontal line shifting
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(require-primitives "core")
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(define-effect scanlines
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:params (
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(amplitude :type int :default 10 :range [0 100])
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(frequency :type int :default 10 :range [1 100])
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(randomness :type float :default 0.5 :range [0 1])
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)
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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 (core:rand-range (- 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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