Re: [O] latex fragment png's size too small

[Feng Shu]

"Feng Shu" <address@hidden> writes:

> Nicolas Goaziou <address@hidden> writes:
>
>> tumashu <address@hidden> writes:
>>
>>> The problem is that the pic is too small and nearly can not see the
>>> words in the picture, it will force user config it, if we use a larger
>>> pic, it can work although it is ugly
>>
>> Then is :scale 1.2 enough?
>
> I tested in bare emacs, 1.2 seem ok. 

I have found the other problem, the below two version of
org-create-formula-image-with-dvipng generate different size png,
for they use different dpi.

I think, we should hold :scale to 1.0 and fix size problem in function
`org-create-formula-image-with-dvipng'.

#+BEGIN_SRC emacs-lisp
;; Old version
(defun org-create-formula-image-with-dvipng (string tofile options buffer)
  "This calls dvipng."
  (require 'ox-latex)
  (let* ((tmpdir (if (featurep 'xemacs)
             (temp-directory)
           temporary-file-directory))
     (texfilebase (make-temp-name
               (expand-file-name "orgtex" tmpdir)))
     (texfile (concat texfilebase ".tex"))
     (dvifile (concat texfilebase ".dvi"))
     (pngfile (concat texfilebase ".png"))
     (fnh (if (featurep 'xemacs)
                  (font-height (face-font 'default))
                (face-attribute 'default :height nil)))
     (scale (or (plist-get options (if buffer :scale :html-scale)) 1.0))
     (dpi (number-to-string (* scale (floor (* 0.9 (if buffer fnh 140.))))))
     (fg (or (plist-get options (if buffer :foreground :html-foreground))
         "Black"))
     (bg (or (plist-get options (if buffer :background :html-background))
             "Transparent")))
    (princ (format "dpi:%s" dpi))
    (if (eq fg 'default) (setq fg (org-dvipng-color :foreground))
      (unless (string= fg "Transparent") (setq fg (org-dvipng-color-format 
fg))))
    (if (eq bg 'default) (setq bg (org-dvipng-color :background))
      (unless (string= bg "Transparent") (setq bg (org-dvipng-color-format 
bg))))
    (let ((latex-header (org-create-formula--latex-header)))
      (with-temp-file texfile
    (insert latex-header)
    (insert "\n\\begin{document}\n" string "\n\\end{document}\n")))
    (let ((dir default-directory))
      (condition-case nil
      (progn
        (cd tmpdir)
        (call-process "latex" nil nil nil texfile))
    (error nil))
      (cd dir))
    (if (not (file-exists-p dvifile))
    (progn (message "Failed to create dvi file from %s" texfile) nil)
      (condition-case nil
      (if (featurep 'xemacs)
          (call-process "dvipng" nil nil nil
                "-fg" fg "-bg" bg
                "-T" "tight"
                "-o" pngfile
                dvifile)
        (call-process "dvipng" nil nil nil
              "-fg" fg "-bg" bg
              "-D" dpi
              ;;"-x" scale "-y" scale
              "-T" "tight"
              "-o" pngfile
              dvifile))
    (error nil))
      (if (not (file-exists-p pngfile))
      (if org-format-latex-signal-error
          (error "Failed to create png file from %s" texfile)
        (message "Failed to create png file from %s" texfile)
        nil)
    ;; Use the requested file name and clean up
    (copy-file pngfile tofile 'replace)
    (loop for e in '(".dvi" ".tex" ".aux" ".log" ".png" ".out") do
          (if (file-exists-p (concat texfilebase e))
          (delete-file (concat texfilebase e))))
    pngfile))))

;; New version
(defun org-create-formula-image-with-dvipng (string tofile options buffer)
  "This calls dvipng."
  (require 'ox-latex)
  (let* ((tmpdir (if (featurep 'xemacs)
             (temp-directory)
           temporary-file-directory))
     (texfilebase (make-temp-name
               (expand-file-name "orgtex" tmpdir)))
     (texfile (concat texfilebase ".tex"))
     (dvifile (concat texfilebase ".dvi"))
     (pngfile (concat texfilebase ".png"))
     (scale (or (plist-get options (if buffer :scale :html-scale)) 1.0))
     ;; This assumes that the display has the same pixel width in
     ;; the horizontal and vertical directions
     (dpi (number-to-string (* scale (if buffer (org--get-display-dpi) 120))))
     (fg (or (plist-get options (if buffer :foreground :html-foreground))
         "Black"))
     (bg (or (plist-get options (if buffer :background :html-background))
             "Transparent")))
    (princ (format "dpi: %s" dpi))
    (if (eq fg 'default) (setq fg (org-dvipng-color :foreground))
      (unless (string= fg "Transparent") (setq fg (org-dvipng-color-format 
fg))))
    (if (eq bg 'default) (setq bg (org-dvipng-color :background))
      (unless (string= bg "Transparent") (setq bg (org-dvipng-color-format 
bg))))
    (let ((latex-header (org-create-formula--latex-header)))
      (with-temp-file texfile
    (insert latex-header)
    (insert "\n\\begin{document}\n" string "\n\\end{document}\n")))
    (let ((dir default-directory))
      (ignore-errors
    (cd tmpdir)
    (call-process "latex" nil nil nil texfile))
      (cd dir))
    (if (not (file-exists-p dvifile))
    (progn (message "Failed to create dvi file from %s" texfile) nil)
      (ignore-errors
    (if (featurep 'xemacs)
        (call-process "dvipng" nil nil nil
              "-fg" fg "-bg" bg
              "-T" "tight"
              "-o" pngfile
              dvifile)
      (call-process "dvipng" nil nil nil
            "-fg" fg "-bg" bg
            "-D" dpi
            ;;"-x" scale "-y" scale
            "-T" "tight"
            "-o" pngfile
            dvifile)))
      (if (not (file-exists-p pngfile))
      (if org-format-latex-signal-error
          (error "Failed to create png file from %s" texfile)
        (message "Failed to create png file from %s" texfile)
        nil)
    ;; Use the requested file name and clean up
    (copy-file pngfile tofile 'replace)
    (dolist (e '(".dvi" ".tex" ".aux" ".log" ".png" ".out"))
      (when (file-exists-p (concat texfilebase e))
        (delete-file (concat texfilebase e))))
    pngfile))))
#+END_SRC



>
>> If it is too ugly, it will also force users configuring it anyway.
>>
>> Regards,

--