gimp/plug-ins/script-fu/scripts/perspective-shadow.scm

197 lines
6.1 KiB
Scheme

; The GIMP -- an image manipulation program
; Copyright (C) 1995 Spencer Kimball and Peter Mattis
;
; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2 of the License, or
; (at your option) any later version.
;
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this program; if not, write to the Free Software
; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
;
;
; perspective-shadow.scm version 1.2 2000/11/08
;
; Copyright (C) 1997-2000 Sven Neumann <sven@gimp.org>
;
;
; Adds a perspective shadow of the current selection or alpha-channel
; as a layer below the active layer
;
(define (script-fu-perspective-shadow image
drawable
alpha
rel-distance
rel-length
shadow-blur
shadow-color
shadow-opacity
interpolation
allow-resize)
(let* ((shadow-blur (max shadow-blur 0))
(shadow-opacity (min shadow-opacity 100))
(shadow-opacity (max shadow-opacity 0))
(rel-length (abs rel-length))
(alpha (* (/ alpha 180) *pi*))
(type (car (gimp-drawable-type-with-alpha drawable)))
(image-width (car (gimp-image-width image)))
(image-height (car (gimp-image-height image)))
(from-selection 0)
(active-selection 0)
(shadow-layer 0))
(if (= rel-distance 0) (set! rel-distance 999999))
(gimp-context-push)
(gimp-image-undo-group-start image)
(gimp-layer-add-alpha drawable)
(if (= (car (gimp-selection-is-empty image)) TRUE)
(begin
(gimp-selection-layer-alpha drawable)
(set! from-selection FALSE))
(begin
(set! from-selection TRUE)
(set! active-selection (car (gimp-selection-save image)))))
(let* ((selection-bounds (gimp-selection-bounds image))
(select-offset-x (cadr selection-bounds))
(select-offset-y (caddr selection-bounds))
(select-width (- (cadr (cddr selection-bounds)) select-offset-x))
(select-height (- (caddr (cddr selection-bounds)) select-offset-y))
(abs-length (* rel-length select-height))
(abs-distance (* rel-distance select-height))
(half-bottom-width (/ select-width 2))
(half-top-width (* half-bottom-width
(/ (- rel-distance rel-length) rel-distance)))
(x0 (+ select-offset-x (+ (- half-bottom-width half-top-width)
(* (cos alpha) abs-length))))
(y0 (+ select-offset-y (- select-height
(* (sin alpha) abs-length))))
(x1 (+ x0 (* 2 half-top-width)))
(y1 y0)
(x2 select-offset-x)
(y2 (+ select-offset-y select-height))
(x3 (+ x2 select-width))
(y3 y2)
(shadow-width (+ (- (max x1 x3) (min x0 x2)) (* 2 shadow-blur)))
(shadow-height (+ (- (max y1 y3) (min y0 y2)) (* 2 shadow-blur)))
(shadow-offset-x (- (min x0 x2) shadow-blur))
(shadow-offset-y (- (min y0 y2) shadow-blur)))
(set! shadow-layer (car (gimp-layer-new image
select-width
select-height
type
"Perspective Shadow"
shadow-opacity
NORMAL-MODE)))
(gimp-image-add-layer image shadow-layer -1)
(gimp-layer-set-offsets shadow-layer select-offset-x select-offset-y)
(gimp-drawable-fill shadow-layer TRANSPARENT-FILL)
(gimp-context-set-background shadow-color)
(gimp-edit-fill shadow-layer BACKGROUND-FILL)
(gimp-selection-none image)
(if (= allow-resize TRUE)
(let* ((new-image-width image-width)
(new-image-height image-height)
(image-offset-x 0)
(image-offset-y 0))
(if (< shadow-offset-x 0)
(begin
(set! image-offset-x (- 0 shadow-offset-x))
(set! new-image-width (- new-image-width image-offset-x))))
(if (< shadow-offset-y 0)
(begin
(set! image-offset-y (- 0 shadow-offset-y))
(set! new-image-height (- new-image-height image-offset-y))))
(if (> (+ shadow-width shadow-offset-x) new-image-width)
(set! new-image-width (+ shadow-width shadow-offset-x)))
(if (> (+ shadow-height shadow-offset-y) new-image-height)
(set! new-image-height (+ shadow-height shadow-offset-y)))
(gimp-image-resize image
new-image-width
new-image-height
image-offset-x
image-offset-y)))
(gimp-drawable-transform-perspective shadow-layer
x0 y0
x1 y1
x2 y2
x3 y3
TRANSFORM-FORWARD interpolation
TRUE 3 FALSE)
(if (>= shadow-blur 1.0)
(begin
(gimp-layer-set-lock-alpha shadow-layer FALSE)
(gimp-layer-resize shadow-layer
shadow-width
shadow-height
shadow-blur
shadow-blur)
(plug-in-gauss-rle 1
image
shadow-layer
shadow-blur
TRUE
TRUE))))
(if (= from-selection TRUE)
(begin
(gimp-selection-load active-selection)
(gimp-edit-clear shadow-layer)
(gimp-image-remove-channel image active-selection)))
(if (and
(= (car (gimp-layer-is-floating-sel drawable)) 0)
(= from-selection FALSE))
(gimp-image-raise-layer image drawable))
(gimp-image-set-active-layer image drawable)
(gimp-image-undo-group-end image)
(gimp-displays-flush)
(gimp-context-pop)))
(script-fu-register "script-fu-perspective-shadow"
_"_Perspective..."
"Add a perspective shadow"
"Sven Neumann <sven@gimp.org>"
"Sven Neumann"
"2000/11/08"
"RGB* GRAY*"
SF-IMAGE "Image" 0
SF-DRAWABLE "Drawable" 0
SF-ADJUSTMENT _"Angle" '(45 0 180 1 10 1 0)
SF-ADJUSTMENT _"Relative distance of horizon" '(5 0 24 .1 1 1 1)
SF-ADJUSTMENT _"Relative length of shadow" '(1 0 24 .1 1 1 1)
SF-ADJUSTMENT _"Blur radius" '(3 0 1024 1 10 0 0)
SF-COLOR _"Color" '(0 0 0)
SF-ADJUSTMENT _"Opacity" '(80 0 100 1 10 0 0)
SF-ENUM _"Interpolation" '("InterpolationType" "linear")
SF-TOGGLE _"Allow resizing" FALSE)
(script-fu-menu-register "script-fu-perspective-shadow"
"<Image>/Filters/Light and Shadow/Shadow")