Bug 121087 - Choppy scrolling in multi-page view; especially with OpenGL enabled but also noticeable without
Summary: Choppy scrolling in multi-page view; especially with OpenGL enabled but also ...
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
(earliest affected) release
Hardware: All Windows (All)
: medium normal
Assignee: Not Assigned
Keywords: bibisected, bisected, regression
Depends on:
Blocks: Scrolling-PageUpDown Multi-Page-View
  Show dependency treegraph
Reported: 2018-10-31 17:31 UTC by Telesto
Modified: 2023-11-01 18:59 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:

Example file (1.06 MB, application/vnd.oasis.opendocument.text)
2018-10-31 17:32 UTC, Telesto
Bibisect log (3.07 KB, text/plain)
2018-10-31 17:33 UTC, Telesto

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Description Telesto 2018-10-31 17:31:49 UTC
Choppy scrolling in multi-page view; especially with OpenGL enabled but also noticeable without

Steps to Reproduce:
1. Open the attached file
2. Go to multipage view (3 pages in a row)
3. Scroll down (notice a lag & higher CPU usage compared to prior versions)

Actual Results:

Expected Results:
Smooth scrolling

Reproducible: Always

User Profile Reset: No

OpenGL enabled: Yes

Additional Info:
Build ID: 4fa9e6f7f891b335ae1b432e0848c1e46c8fe3ef
CPU threads: 4; OS: Windows 6.3; UI render: GL; VCL: win; 
TinderBox: Win-x86@42, Branch:master, Time: 2018-10-30_22:44:48
Locale: nl-NL (nl_NL); Calc: CL
Comment 1 Telesto 2018-10-31 17:32:29 UTC
Created attachment 146212 [details]
Example file
Comment 2 Telesto 2018-10-31 17:33:17 UTC
Created attachment 146213 [details]
Bibisect log

Bisected to:

author	Tor Lillqvist <tml@collabora.com>	2015-08-12 08:18:50 +0300
committer	Tor Lillqvist <tml@collabora.com>	2015-08-12 09:14:20 +0300
commit 4667db065d34193d99bce82f7e8f3b20a03ecade (patch)
tree 405ac0a286040b8a983701f167c583c45691685b
parent 695cec87d73d56617e1cdc62621971ab35ac67eb (diff)
Drop SimpleWinLayout
Use Uniscribe also for non-complex text. It is complicated enough to
have separate Graphite and Uniscribe layout engines. Will make further
changes to the code easier to manage, especially as with the
UniscribeLayout code we have access to the actual
glyphs. (Cf. 3e47219e06b9a279ba22a9bbef668731f2d3e07d)

Comment 3 林佳霈 2018-11-29 08:36:40 UTC
Version: (x64)
Build ID: 0f25a3c36f27fd51453b9a9115f236b83c143684
CPU threads: 8; OS: Windows 10.0; UI render: GL; VCL: win; 
TinderBox: Win-x86_64@42, Branch:master, Time: 2018-11-27_20:06:55
Locale: zh-TW (zh_TW); UI-Language: en-US
Calc: threaded

The new version doesn't have the problem.
Comment 4 Telesto 2018-11-29 09:08:15 UTC
I'm still experiencing a lag
Build ID: f21d2b48bd68424a96aa6cd5572e368208378291
CPU threads: 4; OS: Windows 6.3; UI render: default; VCL: win; 
TinderBox: Win-x86@42, Branch:master, Time: 2018-11-27_00:26:54
Locale: en-US (nl_NL); UI-Language: en-US
Calc: CL
Comment 5 Durgapriyanka 2018-11-29 18:20:41 UTC
I can confirm that the bug is present. I can definitely see the difference in scroll between normal page view and multi page view in my version.

Build ID: 0c292870b25a325b5ed35f6b45599d2ea4458e77
CPU threads: 2; OS: Windows 6.1; UI render: default; 
Locale: en-US (en_US); Calc: group
Comment 6 Xisco Faulí 2018-12-05 13:32:57 UTC
Adding Cc: to Tor Lillqvist
Comment 7 QA Administrators 2022-08-18 03:40:11 UTC Comment hidden (obsolete)
Comment 8 Tor Lillqvist 2023-11-01 12:34:22 UTC
(Pointless to add me as having caused a regression; I am happily retired from LibreOffice.)
Comment 9 Telesto 2023-11-01 18:59:19 UTC
No repro either
Version: (X86_64) / LibreOffice Community
Build ID: be9d7bee88eff89c0d361f23abb447ac2086c3b4
CPU threads: 4; OS: Windows 6.3 Build 9600; UI render: Skia/Raster; VCL: win
Locale: nl-NL (nl_NL); UI: en-US
Calc: CL threaded