Subject: bug#52120: closed (Bug fixed)

From: [email-masked] (GNU bug Tracking System)
Date: Wed, 19 Jan 2022 09:43:02 +0000

Your bug report

#52120: 29.0.50; XRender image transforms many magnitudes faster than Cairo image transforms

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
52120: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=52120
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Bug fixed
From: Po Lu <[email-masked]>
To: [email-masked]
Date: Wed, 19 Jan 2022 17:42:24 +0800
List-Id: <debbugs-submit.debbugs.gnu.org>

Should be fixed in de614ec950.

Subject: 29.0.50; XRender image transforms many magnitudes faster than Cairo image transforms
From: Po Lu <[email-masked]>
To: [email-masked]
Date: Fri, 26 Nov 2021 16:06:46 +0800
List-Id: <debbugs-submit.debbugs.gnu.org>

Try to pixel-scroll (using better-pixel-scroll-mode', soon to be
pixel-scroll-precise-mode) through an image with transforms (you can see
such an example by using eww to browse to gnu.org).

On a build without Cairo, which uses the X rendering extension to
achieve hardware acceleration of image scaling, everything is perfectly
smooth.  On a build with Cairo, it takes around second to scroll through
one or two pixels of such an image.

If nobody else knows why this is the case, I plan to look into it in a
few days, as this is within my field of expertise.  Thanks.

In GNU Emacs 29.0.50 (build 318, x86_64-pc-linux-gnu, GTK+ Version 3.24.30)
 of 2021-11-26 built on trinity
Repository revision: 4e9f78d2a4c5608eeb056b5ecd159b6ea251372e
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101003
System Description: Fedora Linux 35 (Workstation Edition)

Configured using:
 'configure --without-cairo --with-xinput2 --cache-file=/tmp/ccache'

Configured features:
ACL DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON LCMS2
LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG RSVG
SECCOMP SOUND THREADS TIFF TOOLKIT_SCROLL_BARS WEBP X11 XDBE XFT XIM
XINPUT2 XPM GTK3 ZLIB