Re: Drawing in images?

[YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>]

>>>>> On Wed, 26 Aug 2009 00:57:17 +0200, joakim@verona.se said:

> I would like to draw a bounding box inside an image displayed in
> emacs.  Do I:

>  a) use clever already existing way, unknown to me

Maybe existing image slicing and box drawing with face can be used for
some simple cases.

(defface inner-box '((t :box (:line-width -1))) "Simple box")

(defun insert-image-with-box (image x y w h)
  (let* ((image-size (image-size image t))
	 (image-width (car image-size))
	 (image-height (cdr image-size)))
    (if (or (<= w 0) (<= h 0) (< x 0) (< y 0)
	    (> (+ x w) image-width) (> (+ y h) image-height))
	(error "Box empty or not contained in the image")
      (when (> y 0)
	(insert-image image nil nil (list 0 0 image-width y))
	(insert (propertize "\n" 'line-height t)))
      (when (> x 0)
	(insert-image image nil nil (list 0 y x h)))
      (insert (propertize " " 'display `((slice ,x ,y ,w ,h) ,image)
			  'face 'inner-box))
      (when (< (+ x w) image-width)
	(insert-image image nil nil (list (+ x w) y (- image-width x w) h)))
      (insert (propertize "\n" 'line-height t))
      (when (< (+ y h) image-height)
	(insert-image image nil nil (list 0 (+ y h)
					  image-width (- image-height y h)))
	(insert (propertize "\n" 'line-height t))))))

;; Turn off font-lock-mode before you try this in *scratch*.
(insert-image-with-box (create-image "splash.png") 50 30 100 150)

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp