先上效果图
预览用的是 xenops ，优点是异步渲染图片，不会卡; 而且两个模式都能用。
代码主要借鉴自 John Kitchin 的网站：The Kitchin Research Group 。
(setq xenops-math-latex-process-alist
'((dvisvgm :programs
("latex" "dvisvgm")
:description "dvi > svg" :message "you need to install the programs: latex and dvisvgm." :image-input-type "dvi" :image-output-type "svg" :image-size-adjust
(1.7 . 1.5)
:latex-compiler
("latex -interaction nonstopmode -shell-escape -output-format dvi -output-directory %o \"\\nonstopmode\\nofiles\\PassOptionsToPackage{active,tightpage,auctex}{preview}\\AtBeginDocument{\\ifx\\ifPreview\\undefined\\RequirePackage[displaymath,floats,graphics,textmath,footnotes]{preview}[2004/11/05]\\fi}\\input\\detokenize{\"%f\"}\" %f")
:image-converter
("dvisvgm %f -n -b %B -c %S -o %O"))))
(defun xenops-aio-subprocess (command &optional _ __)
"Start asynchronous subprocess; return a promise.
COMMAND is the command to run as an asynchronous subprocess.
Resolve the promise when the process exits. The value function
does nothing if the exit is successful, but if the process exits
with an error status, then the value function signals the error."
(let* ((promise (aio-promise))
(name (format "xenops-aio-subprocess-%s"
(sha1 (prin1-to-string command))))
(output-buffer (generate-new-buffer name))
(sentinel
(lambda (process event)
(unless (process-live-p process)
(aio-resolve
promise
(lambda ()
(if (or (eq 0 (process-exit-status process))
(and (eq 1 (process-exit-status process))
(not (string-match-p
"^! [^P]"
(with-current-buffer output-buffer
(buffer-string))))))
(kill-buffer output-buffer)
(signal 'error
(prog1 (list :xenops-aio-subprocess-error-data
(list (s-join " " command)
event
(with-current-buffer output-buffer
(buffer-string))))
(kill-buffer output-buffer))))))))))
(prog1 promise
(make-process
:name name
:buffer output-buffer
:command command
:sentinel sentinel))))
(defun eli/xenops-preview-align-baseline (element &rest _args)
"Redisplay SVG image resulting from successful LaTeX compilation of ELEMENT.
Use the data in log file (e.g. \"! Preview: Snippet 1 ended.(368640+1505299x1347810).\")
to calculate the decent value of `:ascent'. "
(let* ((inline-p (eq 'inline-math (plist-get element :type)))
(ov-beg (plist-get element :begin))
(ov-end (plist-get element :end))
(colors (xenops-math-latex-get-colors))
(latex (buffer-substring-no-properties ov-beg
ov-end))
(cache-svg (xenops-math-compute-file-name latex colors))
(cache-log (file-name-with-extension cache-svg "log"))
(cache-log-exist-p (file-exists-p cache-log))
(tmp-log (f-join temporary-file-directory "xenops"
(concat (f-base cache-svg) ".log")))
(ov (car (overlays-at (/ (+ ov-beg ov-end) 2) t)))
(regexp-string "^! Preview:.*\(\\([0-9]*?\\)\\+\\([0-9]*?\\)x\\([0-9]*\\))")
img new-img ascent bbox log-text log)
(when (and ov inline-p)
(if cache-log-exist-p
(let ((text (f-read-text cache-log)))
(string-match regexp-string text)
(setq log (match-string 0 text))
(setq bbox (mapcar #'(lambda (x)
(* (preview-get-magnification)
(string-to-number x)))
(list
(match-string 1 text)
(match-string 2 text)
(match-string 3 text)))))
(with-temp-file cache-log
(insert-file-contents-literally tmp-log)
(goto-char (point-max))
(if (re-search-backward regexp-string nil t)
(progn
(setq log (match-string 0))
(setq bbox (mapcar #'(lambda (x)
(* (preview-get-magnification)
(string-to-number x)))
(list
(match-string 1)
(match-string 2)
(match-string 3))))))
(erase-buffer)
(insert log)))
(setq ascent (preview-ascent-from-bb (preview-TeX-bb bbox)))
(setq img (cdr (overlay-get ov 'display)))
(setq new-img (plist-put img :ascent ascent))
(overlay-put ov 'display (cons 'image new-img)))))
(advice-add 'xenops-math-display-image :after
#'eli/xenops-preview-align-baseline)
- 图片居中或右对齐
(plist-put org-format-latex-options :justify 'right)
(defun eli/xenops-justify-fragment-overlay (element &rest _args)
(let* ((ov-beg (plist-get element :begin))
(ov-end (plist-get element :end))
(ov (car (overlays-at (/ (+ ov-beg ov-end) 2) t)))
(position (plist-get org-format-latex-options :justify))
(inline-p (eq 'inline-math (plist-get element :type)))
width offset)
(when (and ov
(imagep (overlay-get ov 'display)))
(setq width (car (image-display-size (overlay-get ov 'display))))
(cond
((and (eq 'center position)
(not inline-p))
(setq offset (floor (- (/ fill-column 2)
(/ width 2))))
(if (< offset 0)
(setq offset 0))
(overlay-put ov 'before-string (make-string offset ? )))
((and (eq 'right position)
(not inline-p))
(setq offset (floor (- fill-column
width)))
(if (< offset 0)
(setq offset 0))
(overlay-put ov 'before-string (make-string offset ? )))))))
(advice-add 'xenops-math-display-image :after
#'eli/xenops-justify-fragment-overlay)
- 公式编号
(defun eli/xenops-renumber-environment (orig-func element latex colors
cache-file display-image)
(let ((results '())
(counter -1)
(numberp))
(setq results (cl-loop for (begin . env) in
(org-element-map (org-element-parse-buffer)
'latex-environment
(lambda (env)
(cons
(org-element-property :begin env)
(org-element-property :value env))))
collect
(cond
((and (string-match "\\\\begin{equation}" env)
(not (string-match "\\\\tag{" env)))
(cl-incf counter)
(cons begin counter))
((and (string-match "\\\\begin{align}" env)
(string-match "\\\\notag" env))
(cl-incf counter)
(cons begin counter))
((string-match "\\\\begin{align}" env)
(prog2
(cl-incf counter)
(cons begin counter)
(with-temp-buffer
(insert env)
(goto-char (point-min))
;; \\ is used for a new line. Each one leads
;; to a number
(cl-incf counter (count-matches "\\\\$"))
;; unless there are nonumbers.
(goto-char (point-min))
(cl-decf counter
(count-matches "\\nonumber")))))
(t
(cons begin nil)))))
(when (setq numberp (cdr (assoc (plist-get element :begin) results)))
(setq latex
(concat
(format "\\setcounter{equation}{%s}\n" numberp)
latex))))
(funcall orig-func element latex colors cache-file display-image))
(advice-add 'xenops-math-latex-create-image :around #'eli/xenops-renumber-environment)
- 预览时显示标签
;; show `#+name:' while in latex preview.
(defun eli/org-preview-show-label (orig-fun beg end &rest _args)
(let* ((beg (save-excursion
(goto-char beg)
(if (re-search-forward "#\\+name:" end t)
(progn
(next-line)
(line-beginning-position))
beg))))
(apply orig-fun beg end _args)))
(advice-add 'org--make-preview-overlay :around #'eli/org-preview-show-label)
效果如下：
这样视觉效果基本就和 pdf 的结果差不多了。
如果不用 xenops 而是用 org-fragtop 或 org 自带的 org-latex-preview ，可以用下面的代码：
代码
;; Vertically align LaTeX preview in org mode
(defun my-org-latex-preview-advice (beg end &rest _args)
(let* ((ov (car (overlays-at (/ (+ beg end) 2) t)))
(img (cdr (overlay-get ov 'display)))
(new-img (plist-put img :ascent 95)))
(overlay-put ov 'display (cons 'image new-img))))
(advice-add 'org--make-preview-overlay
:after #'my-org-latex-preview-advice)
;; from: https://kitchingroup.cheme.cmu.edu/blog/2016/11/06/
;; Justifying-LaTeX-preview-fragments-in-org-mode/
;; specify the justification you want
(plist-put org-format-latex-options :justify 'right)
(defun eli/org-justify-fragment-overlay (beg end image imagetype)
(let* ((position (plist-get org-format-latex-options :justify))
(img (create-image image 'svg t))
(ov (car (overlays-at (/ (+ beg end) 2) t)))
(width (car (image-display-size (overlay-get ov 'display))))
offset)
(cond
((and (eq 'center position)
(= beg (line-beginning-position)))
(setq offset (floor (- (/ fill-column 2)
(/ width 2))))
(if (< offset 0)
(setq offset 0))
(overlay-put ov 'before-string (make-string offset ? )))
((and (eq 'right position)
(= beg (line-beginning-position)))
(setq offset (floor (- fill-column
width)))
(if (< offset 0)
(setq offset 0))
(overlay-put ov 'before-string (make-string offset ? ))))))
(advice-add 'org--make-preview-overlay
:after 'eli/org-justify-fragment-overlay)
;; from: https://kitchingroup.cheme.cmu.edu/blog/2016/11/07/
;; Better-equation-numbering-in-LaTeX-fragments-in-org-mode/
(defun org-renumber-environment (orig-func &rest args)
(let ((results '())
(counter -1)
(numberp))
(setq results (cl-loop for (begin . env) in
(org-element-map (org-element-parse-buffer)
'latex-environment
(lambda (env)
(cons
(org-element-property :begin env)
(org-element-property :value env))))
collect
(cond
((and (string-match "\\\\begin{equation}" env)
(not (string-match "\\\\tag{" env)))
(cl-incf counter)
(cons begin counter))
((and (string-match "\\\\begin{align}" env)
(string-match "\\\\notag" env))
(cl-incf counter)
(cons begin counter))
((string-match "\\\\begin{align}" env)
(prog2
(cl-incf counter)
(cons begin counter)
(with-temp-buffer
(insert env)
(goto-char (point-min))
;; \\ is used for a new line. Each one leads
;; to a number
(cl-incf counter (count-matches "\\\\$"))
;; unless there are nonumbers.
(goto-char (point-min))
(cl-decf counter
(count-matches "\\nonumber")))))
(t
(cons begin nil)))))
(when (setq numberp (cdr (assoc (point) results)))
(setf (car args)
(concat
(format "\\setcounter{equation}{%s}\n" numberp)
(car args)))))
(apply orig-func args))
(advice-add 'org-create-formula-image :around #'org-renumber-environment)
