Hi,
I've created a patch to allow adjusting the scale factor used for inline
latex image fragments. This involves a customizable variable that can
either be set to a scale factor (defaults to 1.0) or a function that
evaluates to a scale factor.
This feature is in addition to the existing scale factor adjustment
capability provided by `org-preview-latex-process-alist' through
`:image-size-adjust'. Wherease image-size-adjust performs scaling at the
time of image generation, the new change performs it during
display. This can lead to significant time saving and suffers no loss of
quality for vector graphics.
As an example of use, I have several functions for changing frame
scaling. I've added
(if (eq major-mode 'org-mode)
(progn
(org-clear-latex-preview)
;; 16 corresponds to the C-u C-u arg prefix.
(org-latex-preview 16)))
to these functions so that changing the frame scaling also
correspondingly changes the latex preview/fragment scaling to match the
new size of the surrounding text. Because of this new feature, this
change is effectively instantaneous for reasonably numbers of
overlays. Obviously, something similar could be done for
`text-scale-adjust' (e.g., through `advice-add').
Feedback appreciated.
Matt
>From 8247947aa6141cde9c58205e0266f0e674226f95 Mon Sep 17 00:00:00 2001
From: Matt Huszagh <huszaghm...@gmail.com>
Date: Sun, 10 Oct 2021 21:20:31 -0700
Subject: [PATCH] org.el: Allow customizing overlay-put scale factor
* lisp/org.el (org-latex-fragment-scale): Add customizable variable
that is equal to or evaluates to a scale factor used to scale inline
latex fragments.
(org--make-preview-overlay): Adjust latex fragment overlay generation
to account for the new custom scale factor.
---
lisp/org.el | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/lisp/org.el b/lisp/org.el
index dbc288a3c..f5e9ff8d1 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -388,6 +388,15 @@ text."
:type '(symbol function integer)
:group 'org)
+(defcustom org-latex-fragment-scale 1.0
+ "Scaling factor used for LaTeX image fragments.
+This can either be a number or a function that takes the image
+data and image type as parameters and evaluates to a number. The
+function can be useful for context-aware scaling, such as setting
+the scale factor to be consistent with the surrounding text size."
+ :type '(number function)
+ :group 'org)
+
;;; Version
(org-check-version)
@@ -16007,7 +16016,13 @@ as a string. It defaults to \"png\"."
(delete-overlay o))))
(overlay-put ov
'display
- (list 'image :type imagetype :file image :ascent ascent)))))
+ (list 'image
+ :type imagetype
+ :file image
+ :ascent ascent
+ :scale (if (functionp org-latex-fragment-scale)
+ (funcall org-latex-fragment-scale image imagetype)
+ org-latex-fragment-scale))))))
(defun org-clear-latex-preview (&optional beg end)
"Remove all overlays with LaTeX fragment images in current buffer.
--
2.31.1
