Matt Huszagh <huszaghm...@gmail.com> writes:
> 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.
Apologies, the patch I sent is slightly wrong. The line numbers also
reflect an earlier patch I made. Here is a corrected version.
>From 3c0e74a8659edb52c1200a02f8a20216b348c4ac 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 405f0f0f9..052212efb 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -320,6 +320,15 @@ identifier."
:version "24.1"
:group 'org-id)
+(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)
@@ -15936,7 +15945,13 @@ as a string. It defaults to \"png\"."
(delete-overlay o))))
(overlay-put ov
'display
- (list 'image :type imagetype :file image :ascent 'center))))
+ (list 'image
+ :type imagetype
+ :file image
+ :ascent 'center
+ :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
