bug#67533: closed (SVG images confound position pixel measurements)

[GNU bug Tracking System]

Your message dated Sat, 16 Dec 2023 17:23:18 +0200
with message-id <83wmtekw7t.fsf@gnu.org>
and subject line Re: bug#67533: SVG images confound position pixel measurements
has caused the debbugs.gnu.org bug report #67533,
regarding SVG images confound position pixel measurements
to be marked as done.

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-- 
67533: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=67533
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> --- Begin Message ---
>
>
>
> Subject: 
>
> SVG images confound position pixel measurements
>
>
>
>
> Date: 
>
> Wed, 29 Nov 2023 15:31:43 -0500
>
>
>
>
> (As posted on emacs-devel)
> ++++++++++++++++++++++
>
> In developing a new pixel-precise smooth scrolling mode, I’ve noticed that 
> inline SVG images confuse Emacs regarding pixel positions of surrounding 
> elements.  You sometimes also experience this while visiting SVG image-rich 
> files (think org-latex-preview) while in visual line mode.  In this case, 
> previous/next-line sometimes jump from one side of the window to the other.  
>
> But it’s easiest to reproduce with line-truncation in effect.  Run the snippet 
> below with your frame either expanded wide enough to accommodate the full width 
> of the 1st line of text, or too narrow (eliciting truncation).  While truly 
> truncated and with point on the SVG, pixel text measurements above are 
> erroneous (reporting zero pixel height above), as if it thinks it’s on the 
> prior line.  At other points in line 2, the pixel-size values are correct.  
>
> This erroneous pixel size/position result occurs whether the image appears via 
> an overlay or a text-property.
>
> Tested in Emacs 29.1 NS and Mac ports.
>
> Small update:  this only occurs when the image is at the start of the line.  
> And PNG images exhibit the same issue.
>
> +++++++
>
> ;;; test-svg-pixel-position --- test pixel position for SVG images
>
> ;;; This small code creates a buffer with two lines, the first of
> ;;; which is long, and the second of which has an SVG image at start.
> ;;; Line truncation is turned on.  `window-text-pixel-size` returns
> ;;; differing results depending on whether truncation is actually in
> ;;; effect (alter the frame width to see this).
>
> ;;; Code:
> (require 'svg)
> (let ((buf "svg-pixel-demo")
>      (svg (svg-create 50 25)))
>  (svg-circle svg 25 25 25 :stroke-color "green")
>  (with-current-buffer (get-buffer-create buf)
>    (erase-buffer)
>    (insert "Pellentesque condimentum, magna ut suscipit hendrerit, ipsum augue 
> ornare nulla, non luctus diam neque sit amet urna.\n")
>    (insert (propertize "THISISACIRCLE" 'display (svg-image svg)))
>    (insert " Aliquam posuere.\n")
>    (pop-to-buffer buf)
>    (goto-char (point-max))
>    (forward-line -1)
>    (toggle-truncate-lines 1)
>    (message "PIXEL SIZE OF LINE ABOVE IMAGE: %S"
>              (window-text-pixel-size nil (cons (point) -1) (point) nil nil nil 
> t))))
>
>
> --- End Message ---
> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#67533: SVG images confound position pixel measurements
>
>
>
>
> Date: 
>
> Sat, 16 Dec 2023 17:23:18 +0200
>
>
>
>
> > From: JD Smith <jdtsmith@gmail.com>
> > Date: Sat, 16 Dec 2023 10:07:33 -0500
> > Cc: 67533@debbugs.gnu.org,
> >  contact@karthinks.com
> > 
> >  On Dec 16, 2023, at 4:32 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> > 
> >  Great, I just recompiled and it’s fixed here too. Will keep an eye out for 
> > any other
> >  image-display issues.  Thanks for your work on this.
> > 
> >  Any further issues, or can this be closed now?
> > 
> > I haven’t encountered any, other than the possibly related motion issue with 
> > inline images in
> > bug#67604.  I believe it can be closed.  
>
> Done.
>
> > Given the unexpected issue that cropped up with org-indent and displayed wide 
> > images, it may be
> > worth stress-testing this fix in buffers with other unusual/wide images 
> > (copying Karthik since I know he
> > often works on latex/org image preview).
>
> Any issues with stuff other than window-text-pixel-size should be
> submitted as separate bugs.  If there are still issues with
> window-text-pixel-size, we can reopen this bug, or start a new one.
>
> Thanks.
>
>
> --- End Message ---