gimp/plug-ins/script-fu/scripts/chrome-it.scm

326 lines
12 KiB
Scheme

; CHROME-IT
; The filter generates a new image, having alpha channels.
; The source image is not touched.
; It renders, not filters.
; The source image is flattened and used as mask for the effect.
; Terminology:
; The effect is commonly known as the "chrome effect".
; "SOTA" means "state of the art" (but the art may have improved.)
; The algorithm's origin is not documented.
; "Stencil" seems to mean that the effect roughly follows the contours
; of shapes in the image, not the usual meaning.
; An adaptor from the original signature and mode requirements
; to a new inner signature and relaxed outer mode requirements.
;
; 1. Adapt to inner signature taking an image instead of a file.
; Adapts env-map, an image file to be opened, to banding-img, an open image.
; When user doesn't choose a file, banding-img is a copy of the primary mask-img.
; The effect is something, if not the same as when user chooses a different image
; than the primary image.
; In SFv2 the file chooser had a default, so the user could NOT choose a None file
; for the env-map file, the secondary image.
;
; The UI design for the secondary "banding image":
; the user must choose a file of an image instead of an open image.
; FUTURE: require the user to choose an open image for the secondary image.
;
; 2. Adapt relaxed outer mode requirement to inner flat requirement.
; Adapt means copy and flatten (delete alpha) before passing to inner.
; The filter originally required a GRAY image without an alpha.
; That produces an image that looks like the source image.
; The inner algorithm also succeeds on any image mode, with or without alpha,
; but the result is less like the source image, in shape.
; For user friendliness, relax the requirements but retain the original effect
; by copying and flattening whatever image is passed.
(define (script-fu-sota-chrome-it mask-img mask-drawables chrome-saturation
chrome-lightness chrome-factor env-map hc cc carve-white)
; use v3 binding of return args from PDB
(script-fu-use-v3)
(let* (
; 1. convert choice of secondary image file to an open image
(banding-img ; secondary, other image
; when user chose no env-map secondary image file
(if (= (string-length env-map) 0)
; copy source image
(gimp-image-duplicate mask-img)
; else open chosen file
(gimp-file-load RUN-NONINTERACTIVE env-map)))
; 2. copy source image, flattened
(copy-source-img (gimp-image-duplicate mask-img))
; side effect on image, not use the returned layer
(flat-source-layer (gimp-image-flatten copy-source-img))
(copy-source-drawables (gimp-image-get-layers copy-source-img)))
; call inner, passing adapted args
(chrome-it-inner
copy-source-img copy-source-drawables ; adapted
chrome-saturation chrome-lightness chrome-factor
banding-img ; adapted
hc cc carve-white)
; Cleanup adapted images
; Inner deletes banding-img
(gimp-image-delete copy-source-img))
)
; The original filter, now taking a image:banding-img instead of file:env-map
(define (chrome-it-inner mask-img mask-drawables chrome-saturation
chrome-lightness chrome-factor banding-img hc cc carve-white)
(define (set-pt a index x y)
(begin
(vector-set! a (* index 2) x)
(vector-set! a (+ (* index 2) 1) y)))
(define (spline-chrome-it)
(let* ((a (cons-array 18 'double)))
(set-pt a 0 0.0 0.0)
(set-pt a 1 0.125 0.9216)
(set-pt a 2 0.25 0.0902)
(set-pt a 3 0.375 0.9020)
(set-pt a 4 0.5 0.0989)
(set-pt a 5 0.625 0.9549)
(set-pt a 6 0.75 00784)
(set-pt a 7 0.875 0.9412)
(set-pt a 8 1.0 0.1216)
a))
(define (shadows val)
(/ (* 0.96 val) 2.55))
(define (midtones val)
(/ val 2.55))
(define (highlights val)
; The result is used as "gimp-drawable-color-balance" color parameter
; and thus must be restricted to -100.0 <= highlights <= 100.0.
(min (/ (* 1.108 val) 2.55) 100.0))
(define (rval col)
(car col))
(define (gval col)
(cadr col))
(define (bval col)
(caddr col))
(define (sota-scale val scale chrome-factor)
(* (sqrt val) (* scale chrome-factor)))
(define (copy-layer-chrome-it dest-image dest-drawable source-image source-drawable)
(gimp-selection-all dest-image)
(gimp-drawable-edit-clear dest-drawable)
(gimp-selection-none dest-image)
(gimp-selection-all source-image)
(gimp-edit-copy (vector source-drawable))
(let* (
(pasted (gimp-edit-paste dest-drawable #f))
(num-pasted (vector-length pasted))
(floating-sel (vector-ref pasted (- num-pasted 1)))
)
(gimp-floating-sel-anchor floating-sel)))
(let* (
(banding-layer (vector-ref (gimp-image-get-selected-drawables banding-img) 0))
(banding-height (gimp-drawable-get-height banding-layer))
(banding-width (gimp-drawable-get-width banding-layer))
(banding-type (gimp-drawable-type banding-layer))
(mask-drawable (vector-ref mask-drawables 0))
(width (gimp-drawable-get-width mask-drawable))
(height (gimp-drawable-get-height mask-drawable))
(img (gimp-image-new width height GRAY))
(size (min width height))
(offx1 (sota-scale size 0.33 chrome-factor))
(offy1 (sota-scale size 0.25 chrome-factor))
(offx2 (sota-scale size (- 0.33) chrome-factor))
(offy2 (sota-scale size (- 0.25) chrome-factor))
(feather (sota-scale size 0.5 chrome-factor))
(brush-size (sota-scale size 0.5 chrome-factor))
(brush (gimp-brush-new "Chrome It"))
(mask (gimp-channel-new img "Chrome Stencil" width height 50 '(0 0 0)))
(bg-layer (gimp-layer-new img width height GRAY-IMAGE _"Background" 100 LAYER-MODE-NORMAL))
(layer1 (gimp-layer-new img banding-width banding-height banding-type _"Layer 1" 100 LAYER-MODE-NORMAL))
(layer2 (gimp-layer-new img width height GRAYA-IMAGE _"Layer 2" 100 LAYER-MODE-DIFFERENCE))
(layer3 (gimp-layer-new img width height GRAYA-IMAGE _"Layer 3" 100 LAYER-MODE-NORMAL))
(shadow (gimp-layer-new img width height GRAYA-IMAGE _"Drop Shadow" 100 LAYER-MODE-NORMAL))
(layer-mask 0)
(marble-pattern (gimp-pattern-get-by-name "Marble #1"))
)
(gimp-context-push)
(gimp-context-set-defaults)
(gimp-image-undo-disable img)
(gimp-image-insert-channel img mask -1 0)
(gimp-image-insert-layer img bg-layer 0 0)
(gimp-image-insert-layer img shadow 0 0)
(gimp-image-insert-layer img layer3 0 0)
(gimp-image-insert-layer img layer2 0 0)
(gimp-edit-copy (vector mask-drawable))
; Clipboard is copy of mask-drawable. Paste into mask, a channel, and anchor it.
(let* (
(pasted (gimp-edit-paste mask #f))
(num-pasted (vector-length pasted))
(floating-sel (vector-ref pasted (- num-pasted 1)))
)
(gimp-floating-sel-anchor floating-sel)
)
; carve-white is 0 or 1, not #f or #t
(if (= carve-white TRUE)
(gimp-drawable-invert mask #f))
(gimp-context-set-background '(255 255 255))
(gimp-selection-none img)
(gimp-drawable-edit-fill layer2 FILL-BACKGROUND)
(gimp-drawable-edit-fill layer3 FILL-BACKGROUND)
(gimp-drawable-edit-clear shadow)
(gimp-item-set-visible bg-layer #f)
(gimp-item-set-visible shadow #f)
(gimp-image-select-item img CHANNEL-OP-REPLACE mask)
(gimp-context-set-background '(0 0 0))
(gimp-selection-translate img offx1 offy1)
(gimp-selection-feather img feather)
(gimp-drawable-edit-fill layer2 FILL-BACKGROUND)
(gimp-selection-translate img (* 2 offx2) (* 2 offy2))
(gimp-drawable-edit-fill layer3 FILL-BACKGROUND)
(gimp-selection-none img)
(set! layer2 (gimp-image-merge-visible-layers img CLIP-TO-IMAGE))
(gimp-drawable-invert layer2 #f)
(gimp-image-insert-layer img layer1 0 0)
(copy-layer-chrome-it img layer1 banding-img banding-layer)
(gimp-image-delete banding-img)
(gimp-layer-scale layer1 width height #f)
(plug-in-gauss RUN-NONINTERACTIVE img layer1 3.2 3.2 0)
(gimp-layer-set-opacity layer1 50)
(set! layer1 (gimp-image-merge-visible-layers img CLIP-TO-IMAGE))
(gimp-drawable-curves-spline layer1 HISTOGRAM-VALUE (spline-chrome-it))
(set! layer-mask (gimp-layer-create-mask layer1 ADD-MASK-BLACK))
(gimp-layer-add-mask layer1 layer-mask)
(gimp-image-select-item img CHANNEL-OP-REPLACE mask)
(gimp-context-set-background '(255 255 255))
(gimp-drawable-edit-fill layer-mask FILL-BACKGROUND)
(set! layer2 (gimp-layer-copy layer1 #t))
(gimp-image-insert-layer img layer2 0 0)
(gimp-brush-set-shape brush BRUSH-GENERATED-CIRCLE)
(gimp-brush-set-spikes brush 2)
(gimp-brush-set-hardness brush 1.0)
(gimp-brush-set-spacing brush 25)
(gimp-brush-set-aspect-ratio brush 1)
(gimp-brush-set-angle brush 0)
(cond (<= brush-size 17) (gimp-brush-set-radius brush (\ brush-size 2))
(else gimp-brush-set-radius brush (\ 19 2)))
(gimp-context-set-brush brush)
(gimp-context-set-foreground '(255 255 255))
(gimp-drawable-edit-stroke-selection layer-mask)
(gimp-context-set-background '(0 0 0))
(gimp-selection-feather img (* feather 1.5))
(gimp-selection-translate img (* 2.5 offx1) (* 2.5 offy1))
(gimp-drawable-edit-fill shadow FILL-BACKGROUND)
(gimp-selection-all img)
(gimp-context-set-pattern marble-pattern)
(gimp-drawable-edit-fill bg-layer FILL-PATTERN)
(gimp-selection-none img)
(gimp-image-convert-rgb img)
(gimp-drawable-color-balance layer1 TRANSFER-SHADOWS #t
(shadows (rval hc))
(shadows (gval hc))
(shadows (bval hc)))
(gimp-drawable-color-balance layer1 TRANSFER-MIDTONES #t
(midtones (rval hc))
(midtones (gval hc))
(midtones (bval hc)))
(gimp-drawable-color-balance layer1 TRANSFER-HIGHLIGHTS #t
(highlights (rval hc))
(highlights (gval hc))
(highlights (bval hc)))
(gimp-drawable-color-balance layer2 TRANSFER-SHADOWS #t
(shadows (rval cc))
(shadows (gval cc))
(shadows (bval cc)))
(gimp-drawable-color-balance layer2 TRANSFER-MIDTONES #t
(midtones (rval cc))
(midtones (gval cc))
(midtones (bval cc)))
(gimp-drawable-color-balance layer2 TRANSFER-HIGHLIGHTS #t
(highlights (rval cc))
(highlights (gval cc))
(highlights (bval cc)))
(gimp-drawable-hue-saturation layer2 HUE-RANGE-ALL
0.0
chrome-lightness
chrome-saturation
0.0)
(gimp-item-set-visible shadow #t)
(gimp-item-set-visible bg-layer #t)
(gimp-item-set-name layer2 _"Chrome")
(gimp-item-set-name layer1 _"Highlight")
(gimp-image-remove-channel img mask)
(gimp-resource-delete brush)
(gimp-display-new img)
(gimp-image-undo-enable img)
(gimp-context-pop)
)
)
; FIXME the description is confusing:
; 1. Filter renders a new image and does not "add ... to selected region"
; 2. It is unclear that "specified..stencil" refers to the source image
; and doesn't mean the secondary "Environment map"
; 3. The original did not permit an alpha so "(or alpha)" is unclear
; Suggest: "Renders a new image having a chrome effect on shapes in the image."
(script-fu-register-filter "script-fu-sota-chrome-it"
_"Stencil C_hrome..."
_"Add a chrome effect to the selected region (or alpha) using a specified (grayscale) stencil"
"Spencer Kimball"
"Spencer Kimball"
"1997"
"*"
SF-ONE-OR-MORE-DRAWABLE
SF-ADJUSTMENT _"Chrome saturation" '(-80 -100 100 1 10 0 0)
SF-ADJUSTMENT _"Chrome lightness" '(-47 -100 100 1 10 0 0)
SF-ADJUSTMENT _"Chrome factor" '(0.75 0 1 0.1 0.2 2 0)
SF-FILENAME _"Environment map"
(string-append gimp-data-directory
"/scripts/images/beavis.jpg")
SF-COLOR _"Highlight balance" '(211 95 0)
SF-COLOR _"Chrome balance" "black"
SF-TOGGLE _"Chrome white areas" #t
)
(script-fu-menu-register "script-fu-sota-chrome-it"
"<Image>/Filters/Decor")