Bug 166701 - SLIDESHOW: Mouse-as-pen notes can be generated differently (single or multiple shapes)
Summary: SLIDESHOW: Mouse-as-pen notes can be generated differently (single or multipl...
Status: UNCONFIRMED
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Impress (show other bugs)
Version:
(earliest affected)
24.2.7.2 release
Hardware: All Linux (All)
: medium minor
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-05-23 12:18 UTC by Alex
Modified: 2026-01-16 03:11 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:


Attachments
Same document with both "kinds of ink" made with the same setup (32.73 KB, application/vnd.oasis.opendocument.presentation)
2025-05-23 12:18 UTC, Alex
Details
inxi of the system that shows (by default) multiple lines (3.23 KB, text/plain)
2025-05-23 12:19 UTC, Alex
Details
Enlarged portion of option b) with individual strokes colored (37.84 KB, image/jpeg)
2026-01-15 09:12 UTC, Alex
Details

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Description Alex 2025-05-23 12:18:08 UTC
Description:
Depending on factors I have not yet completely understood, the defaults for drawings made using "mouse-as-pen" while presenting are generated using either

a) as one single trace (starting when the mouse/pen is pressed until it is release) or
b) as a set of lines and polylines with only a few points each (ungrouped)

Steps to Reproduce:
Start a slideshow in Impress (with mouse as pen enabled) and draw e.g. a circle. In some cases, I get a closed line, version a). For others I get version b).

Actual Results:
I added a test document where both varieties can be seen.

If mostly seen type a), though especially one systems insists in version b).

Note that, so far, I did not see the problem on LO running on Windows 10/11, also, not all Linux I had tested were affected.

I tried a variety of Linux Distributions (Kubuntu 24.10, Mint 22.1, Ubuntu 24.04 LTS) freshly booted up on different hardware. LO Versions are summarized below, but in fact the version didn't matter so much.

Mostly, I find version a) (a single line) to be present.
On especially one system (in the list, those entries with 12 cores), though, freshly installed versions up to 25.2.4.0.0+ (4fb6cb4929312af91d7b0b5755bf2d116006fbaa) showed version b). *EXCEPT* the Flatpack version (with it's own config files), which after a few days of trial and error suddenly switched from b) to a). So I compared the config files and found, that the "View Mode" of the presenter screen determines (on this system !) if option a) or b) is found.

In registrymodifications.xcu it's the following line:

<item oor:path="/org.openoffice.Office.PresenterScreen/Presenter"><prop oor:name="InitialViewMode" oor:op="fuse"><value>2</value></prop></item>

If that's set to 2 (all slides overview), I get a single polyline (a)). If I switch to either no presenter screen or any other view, I get a set of lines (b)).

Note, that for most systems, it doesn't matter - I end up with option a) anyway.
I realize that this is probably not the root cause, but that's how far I could track down the differences between the two LO setups on the same system.

Expected Results:
Either a) or b), but preferably a) :)


Reproducible: Sometimes


User Profile Reset: Yes

Additional Info:
*Multiple Lines* (without workaround)
Version: 25.2.4.0.0+ (X86_64) / LibreOffice Community
Build ID: 4fb6cb4929312af91d7b0b5755bf2d116006fbaa
CPU threads: 12; OS: Linux 6.8; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: CL threaded

Version: 25.2.3.2 (X86_64) / LibreOffice Community
Build ID: bbb074479178df812d175f709636b368952c2ce3
CPU threads: 12; OS: Linux 6.8; UI render: default; VCL: gtk3
Locale: en-US (C.UTF-8); UI: en-US
Flatpak
Calc: threaded

Version: 24.8.2.1 (X86_64) / LibreOffice Community
Build ID: 480(Build:1)
CPU threads: 12; OS: Linux 6.11; UI render: default; VCL: kf6 (cairo+xcb)
Locale: en-US (C.UTF-8); UI: en-US
Ubuntu package version: 4:24.8.2-0ubuntu1
Calc: threaded

Version: 24.2.7.2 (X86_64) / LibreOffice Community
Build ID: 420(Build:2)
CPU threads: 12; OS: Linux 6.8; UI render: default; VCL: gtk3
Locale: en-US (C.UTF-8); UI: en-US
Ubuntu package version: 4:24.2.7-0ubuntu0.24.04.1
Calc: threaded

*Single Line* (directly, now workaround needed)
Version: 25.2.3.2 (X86_64) / LibreOffice Community
Build ID: bbb074479178df812d175f709636b368952c2ce3
CPU threads: 4; OS: Windows 11 X86_64 (10.0 build 26100); UI render: Skia/Raster; VCL: win
Locale: de-DE (de_DE); UI: de-DE
Calc: threaded

Version: 25.2.3.2 (X86_64) / LibreOffice Community
Build ID: bbb074479178df812d175f709636b368952c2ce3
CPU threads: 8; OS: Windows 11 X86_64 (10.0 build 22631); UI render: Skia/Raster; VCL: win
Locale: de-DE (de_DE); UI: de-DE
Calc: threaded

Version: 24.2.7.2 (X86_64) / LibreOffice Community
Build ID: 420(Build:2)
CPU threads: 8; OS: Linux 6.8; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: de-DE
Ubuntu package version: 4:24.2.7-0ubuntu0.24.04.4
Calc: threaded
Comment 1 Alex 2025-05-23 12:18:56 UTC
Created attachment 200927 [details]
Same document with both "kinds of ink" made with the same setup
Comment 2 Alex 2025-05-23 12:19:54 UTC
Created attachment 200928 [details]
inxi of the system that shows (by default) multiple lines
Comment 3 Jeremy Norvell 2025-05-24 21:55:31 UTC
I attempted to reproduce this on two Linux (Mint) installs and one MacOS install. I wasn't able to duplicate the "type b" (polyline) versions in any of them. 

I wanted to add this information in case it helps aid in reproducing the behavior.

Version: 25.8.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: 866538a4aeb30a598a6ede3d1763d898eb1920b0
CPU threads: 2; OS: Linux 6.8; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded

Version: 24.2.7.2 (X86_64) / LibreOffice Community
Build ID: 420(Build:2)
CPU threads: 2; OS: Linux 6.8; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US
Ubuntu package version: 4:24.2.7-0ubuntu0.24.04.4
Calc: threaded

Version: 25.8.0.0.alpha1+ (X86_64) / LibreOffice Community
Build ID: 84da1f50ca8261129909901c2ff72adb9c67510a
CPU threads: 8; OS: macOS 15.2; UI render: Skia/Raster; VCL: osx
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded
Comment 4 Buovjaga 2025-12-26 16:00:09 UTC
Did Regina's commit for bug 166647 have any effect on this?
Comment 5 Alex 2026-01-15 09:11:39 UTC
I didn't have the time to test that particular problem so far on that system, sorry - I'll do as soon as possible.

However, in the meantime, something else caught my attention:

As far as I understand, LO will (initially) record all drawings as "mode b)" - i.e. a set of straight lines. Until that was fixed by combining those lines to one (and subsequently simplifying the polyline) LO would always create and store something close to version b) as is.

I think the relevant part of code is here, the concatenation is done on a "last point equals next point" basis: https://git.libreoffice.org/core/+/a98b1523141a8c3bed01ee9781f6b4844960bd73/slideshow/source/engine/slideshowimpl.cxx#1550 

In the example I uploaded, if you zoom in to the drawing of the "b", none of the individual parts have any overlapping points. Now that's logical to some extend because what I see in the file is already the _result_ of the process, or the leftovers of the concatenation process.
What is interesting, though, is, that _lines_ do cross each other, as if the position of the pointer was "jumping up and down" during drawing.

I'll attach a picture with some enhancement - there I colored individual portions of the top of the 1st stroke of the b with end-points enlarged, I was drawing top to bottom. Note that the height of the "excerpt" I colored is roughly 6mm in height, which I believe calculates to something around 20 pixels for anything between 72 and 96 dpi (I don't know which relation LO is using).

My guess is: if, for any reason, some jitter is seen on the positions of the pointing device, and the points being stored are off by maybe just one pixel, combining would fail on some of those strokes? I'm not sure how that would align with the other observations I made.

I'll try to reproduce the problem once again. If what I made up here is true, I'm not sure how LO would address this; maybe adding some "DPI-based" threshold for Point1 = Point2 could be possible? Or I need to get a better mouse :-)
Comment 6 Alex 2026-01-15 09:12:20 UTC
Created attachment 205057 [details]
Enlarged portion of option b) with individual strokes colored
Comment 7 QA Administrators 2026-01-16 03:11:51 UTC Comment hidden (obsolete)