Files
test/sexp_effects/effects/layer.sexp
gilesb e3c6163e2e Add ascii_dual_blend recipe and fix blend/layer effects
- Add ascii_dual_blend.sexp: blends two ASCII-processed videos synced to audio
- Fix blend.sexp: add require-primitives, fix params syntax
- Fix layer.sexp: add require-primitives
- Use consistent (effect blend ...) syntax instead of special form

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-20 09:19:40 +00:00

29 lines
975 B
Common Lisp

;; Layer effect - composite frame-b over frame-a at position
;; Multi-input effect: uses frame-a (background) and frame-b (overlay)
;; Params: x, y (position), opacity (0-1), mode (blend mode)
(require-primitives "image" "blending")
(define-effect layer
:params (
(x :type int :default 0)
(y :type int :default 0)
(opacity :type float :default 1.0)
(mode :type string :default "alpha")
)
(let [bg (copy frame-a)
fg frame-b
;; Resize fg if needed to fit
fg-w (width fg)
fg-h (height fg)]
(if (= opacity 1.0)
;; Simple paste
(paste bg fg x y)
;; Blend with opacity
(let [blended (if (= mode "alpha")
(blend-images (crop bg x y fg-w fg-h) fg opacity)
(blend-images (crop bg x y fg-w fg-h)
(blend-mode (crop bg x y fg-w fg-h) fg mode)
opacity))]
(paste bg blended x y)))))