如何对齐 org-latex-preview 预览图的水平基准线?
按照当前思路用最简单的方式优化了基线校准, 最终效果如下:
与原本的效果对比:
旧:
新:
由于实现方式很简单, 只是单纯检查内容是否有上下标. 然后根据这些来单个调整图片位置.
所以目前还有许多不完善的地方, 希望能够慢慢修正.
代码如下:
(defun my/org-latex--get-tex-string ()
"Return the content of the LaTeX fragment at point."
(let ((datum (org-element-context)))
(org-element-property :value datum)))
(defun my/latex-fragment-superscript-p ()
"Return `t' if '^' in current LaTeX fragment."
(memq 94 (string-to-list (my/org-latex--get-tex-string))))
(defun my/latex-fragment-subscript-p ()
"Return `t' if '_' in current LaTeX fragment."
(memq 95 (string-to-list (my/org-latex--get-tex-string))))
(defun my/latex-fragment-script-p ()
"Return `t' if both '_' & '^' in current LaTeX fragment."
(and (memq 94 (string-to-list (my/org-latex--get-tex-string)))
(memq 95 (string-to-list (my/org-latex--get-tex-string)))))
(defun org--make-preview-overlay (beg end image &optional imagetype)
"Build an overlay between BEG and END using IMAGE file.
Argument IMAGETYPE is the extension of the displayed image,
as a string. It defaults to \"png\"."
(setq my/position 'center)
(cond ((my/latex-fragment-script-p)
(setq my/position 'center))
((my/latex-fragment-superscript-p)
(setq my/position 100))
((my/latex-fragment-subscript-p)
(setq my/position 70)))
(let ((ov (make-overlay beg end))
(imagetype (or (intern imagetype) 'png)))
(overlay-put ov 'org-overlay-type 'org-latex-overlay)
(overlay-put ov 'evaporate t)
(overlay-put ov
'modification-hooks
(list (lambda (o _flag _beg _end &optional _l)
(delete-overlay o))))
(overlay-put ov
'display
(list 'image :type imagetype :file image :ascent my/position))))
当然除此之外, 精准的基线校准方案依然是有的, 比如
(texfrag 我很难读懂它的代码, 没有明白它的实现方式.)
同时 dvisvgm 文档中所描述的解决方案: dvisvgm: Generating scalable vector graphics from DVI and EPS files, p363. 与 preview-latex 并调整 preview.el 的变量而可能实现的一种较为完美的解决方案. 但本人目前还没有找到具体实现方式.