Files
rose-ash/l1/sexp_effects/effects/mosaic.sexp
2026-02-24 23:07:19 +00:00

31 lines
956 B
Common Lisp

;; Mosaic effect - built from primitive xector operations
;;
;; Uses:
;; pool-frame - downsample to cell averages
;; cell-indices - which cell each pixel belongs to
;; gather - look up cell value for each pixel
(require-primitives "xector")
(define-effect mosaic
:params (
(cell-size :type int :default 16 :range [4 64] :desc "Size of mosaic cells")
)
(let* (
;; Pool frame to get average color per cell (returns r,g,b,lum xectors)
(pooled (pool-frame frame cell-size))
(cell-r (nth pooled 0))
(cell-g (nth pooled 1))
(cell-b (nth pooled 2))
;; For each output pixel, get its cell index
(cell-idx (cell-indices frame cell-size))
;; Gather: look up cell color for each pixel
(out-r (gather cell-r cell-idx))
(out-g (gather cell-g cell-idx))
(out-b (gather cell-b cell-idx)))
;; Reconstruct frame
(rgb out-r out-g out-b)))