;
; Stair Interpolation, V2.1
;
; Martin Egger (martin.egger@gmx.net)
; (C) 2005, Bern, Switzerland
;
; The image will be enlarged in 10% steps up to the specified factor using 
; best available (=Lanczos) interpolation.
;
; This plugin was tested with Gimp 2.4
;
; 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.
;
; Define the function
;
(define (script-fu-Eg-StairInterpolation_test InImage InLayer)
;		
	(let*	(
		(InFactor 2.0)
		(TheImage (car (gimp-image-duplicate InImage)))
		(TheLayer (car (gimp-image-flatten TheImage)))
		(Step (* 10 (- InFactor 1)))
		(TheWidth (car (gimp-image-width TheImage)))
		(TheHeight (car (gimp-image-height TheImage)))
		(TotWidth (* InFactor TheWidth))
		(TotHeight (* InFactor TheHeight))
		(IncWidth (/ (- TotWidth TheWidth) Step))
		(IncHeight (/ (- TotHeight TheHeight) Step))
		(Counter 1)
		)
		(gimp-image-undo-disable TheImage)
		(gimp-selection-none TheImage)
;
; Resize the image
;
		(while (<= Counter Step)

			(let*	(
				(NewWidth (+ TheWidth (* Counter IncWidth)))
				(NewHeight (+ TheHeight (* Counter IncHeight)))
				)
				(gimp-drawable-transform-scale TheLayer 0.0 0.0 NewWidth NewHeight TRANSFORM-FORWARD INTERPOLATION-NONE TRUE 3 FALSE)
				(set! Counter (+ Counter 1))
			)
		)
		(gimp-image-resize-to-layers TheImage)
		(gimp-display-new TheImage)
		(gimp-drawable-set-name TheLayer "StairInterpolated")
		(gimp-image-undo-enable TheImage)
	)
;
; Finish work
;
	(gimp-displays-flush)
;
)
;
; Register the function with the GIMP
;
(script-fu-register
	"script-fu-Eg-StairInterpolation_test"
	_"S_tair Interpolation_Test"
	"Resize images using Stair Inperpolation with Lanczos algorithm"
	"Martin Egger (martin.egger@gmx.net)"
	"2005, Martin Egger, Bern, Switzerland"
	"3.10.2005"
	"RGB* GRAY*"
	SF-IMAGE	"The Image"	0
	SF-DRAWABLE	"The Layer"	0
)
;
(script-fu-menu-register "script-fu-Eg-StairInterpolation_test"
			 "<Image>/Filters/Eg")
;