Re: [PATCH] org.el: Allow transparent background in latex images

2020-09-23 Thread Bastien
Hi Roshan,

Applied as 2f9e1569f in master.

Thanks!

-- 
 Bastien



[PATCH] org.el: Allow transparent background in latex images

2020-09-16 Thread Roshan Shariff
* lisp/org.el (org-create-formula-image): When `:background' is set to
"Transparent" in `org-format-latex-options', do not output a
`\pagecolor{...}' command in the generated LaTeX file.  This will
cause dvisvgm, convert, or dvipng (with the `-bg Transparent' option)
to produce png or svg images with a transparent background.

* lisp/org.el (org-preview-latex-process-alist): Add the `-bg
Transparent' command-line option to dvipng, which causes it to produce
a PNG with an alpha channel when the dvi file has no `\background'
special.

TINYCHANGE
---
 lisp/org.el | 16 +---
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/lisp/org.el b/lisp/org.el
index 053635c85..108dc6b5b 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -3282,7 +3282,7 @@ All available processes and theirs documents can be found 
in
  :image-output-type "png"
  :image-size-adjust (1.0 . 1.0)
  :latex-compiler ("latex -interaction nonstopmode -output-directory %o %f")
- :image-converter ("dvipng -D %D -T tight -o %O %f"))
+ :image-converter ("dvipng -D %D -T tight -bg Transparent -o %O %f"))
 (dvisvgm
  :programs ("latex" "dvisvgm")
  :description "dvi > svg"
@@ -16146,10 +16146,10 @@ a HTML file."
 (if (eq fg 'default)
(setq fg (org-latex-color :foreground))
   (setq fg (org-latex-color-format fg)))
-(if (eq bg 'default)
-   (setq bg (org-latex-color :background))
-  (setq bg (org-latex-color-format
-   (if (string= bg "Transparent") "white" bg
+(setq bg (cond
+ ((eq bg 'default) (org-latex-color :background))
+ ((string= bg "Transparent") nil)
+ (t (org-latex-color-format bg
 ;; Remove TeX \par at end of snippet to avoid trailing space.
 (if (string-suffix-p string "\n")
 (aset string (1- (length string)) ?%)
@@ -16158,8 +16158,10 @@ a HTML file."
   (insert latex-header)
   (insert "\n\\begin{document}\n"
  "\\definecolor{fg}{rgb}{" fg "}%\n"
- "\\definecolor{bg}{rgb}{" bg "}%\n"
- "\n\\pagecolor{bg}%\n"
+ (if bg
+ (concat "\\definecolor{bg}{rgb}{" bg "}%\n"
+ "\n\\pagecolor{bg}%\n")
+   "")
  "\n{\\color{fg}\n"
  string
  "\n}\n"
-- 
2.26.2