Add gimp script-fu code for cropping tree sprites

scripts/script-fu.scm

@@ -0,0 +1,73 @@
+;; Utilities
+
+(define (take count sequence)
+  (reverse
+   (let loop ((res '()) (rem sequence) (n count))
+	 (if (or (null? rem) (= 0 n))
+		 res
+		 (loop (cons (car rem) res) (cdr rem) (- n 1))))))
+
+(define (skip count sequence)
+  (let loop ((rem sequence) (n count))
+	(if (or (null? rem) (= 0 n))
+		rem
+		(loop (cdr rem) (- n 1)))))
+
+(define (replace old new sequence)
+  (let ((n (length old)))
+	(let loop ((pre '())
+			   (rem sequence))
+	  (cond ((null? rem) (append (reverse pre) rem))
+			((equal? old (take n rem))
+			 (append (reverse pre) new (skip n rem)))
+			(else (loop (cons (car rem) pre) (cdr rem)))))))
+
+(define (string-replace old new string)
+  (list->string
+   (replace (string->list old)
+			(string->list new)
+			(string->list string))))
+
+(define (foreach-image f)
+  (let* ((list-result (gimp-image-list))
+		 (count (car list-result))
+		 (ids (cadr list-result)))
+	(do ((i 0 (+ i 1)))
+		((>= i count))
+	  (f (vector-ref ids i))))
+  (gimp-displays-flush))
+
+(define (export-png image path)
+  (gimp-context-push)
+  (let* ((original-active-layer (car (gimp-image-get-active-drawable image)))
+		 (temp-image (car (gimp-image-duplicate image)))
+		 (merged-layer
+		  (car (gimp-image-merge-visible-layers temp-image CLIP-TO-IMAGE))))
+	(file-png-save-defaults RUN-NONINTERACTIVE
+							temp-image merged-layer path path)
+	(gimp-image-delete temp-image)
+	(gimp-image-set-active-layer image original-active-layer))
+  (gimp-context-pop))
+
+(define (active-image)
+  (vector-ref (cadr (gimp-image-list)) 0))
+
+;; Cropping tree sprites
+
+(define (crop-to-middle-sprite image)
+  (let* ((width (car (gimp-image-width image)))
+		 (height (car (gimp-image-height image)))
+		 (sprite-width (quotient width 3)))
+	(gimp-image-crop image sprite-width height sprite-width 0)
+	(gimp-displays-flush)))
+
+(define (tree-sprite-export-path image)
+  (string-replace "originals/Cute_Fantasy/Trees" "sprites/trees"
+				  (car (gimp-image-get-filename image))))
+
+(define (export-tree-sprite image)
+  (export-png image (tree-sprite-export-path image)))
+
+(define (crop-and-export-tree-sprite image)
+  (crop-to-middle-sprite image)
+  (export-tree-sprite image))