From fd5593c7f254e2c8893feaf6b10715d375b10013 Mon Sep 17 00:00:00 2001 From: Po Lu Date: Sun, 3 Sep 2023 09:25:06 +0800 Subject: [PATCH] * etc/PROBLEMS: Mention bug#65432 and its remedy. --- etc/PROBLEMS | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/etc/PROBLEMS b/etc/PROBLEMS index 6585d5b479d..f398244f3bb 100644 --- a/etc/PROBLEMS +++ b/etc/PROBLEMS @@ -1624,6 +1624,18 @@ to normal, do (set-scroll-bar-mode 'left) +*** Redisplay with scaled images is slow when built with Cairo. + +Cairo expends a noticeable amount of time displaying large images with +a transform applied. These images most frequently appear within Eww +buffers or Image Mode buffers after executing the image scaling +commands `i +' or `i -', and their presence incurs a performance +penalty of hundereds of milliseconds to seconds upon redisplay. The +remedy is to build without Cairo after verifying the XRender extension +is present on your X server and its headers are present on your +system, whereupon Emacs will use that extension to efficiently perform +image transforms within the X server. + *** Error messages about undefined colors on X. The messages might say something like this: -- 2.39.2