Path: csiph.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From: Gerhard Strangar <g.s@arcor.de>
Newsgroups: comp.os.linux.misc
Subject: Re: Need Help With Libinput
Date: Wed, 3 Jul 2024 05:55:40 +0000
Lines: 20
Message-ID: <lek7esF2l4rU1@mid.individual.net>
References: <17de7c0ce189fbc8$526471$1616079$802601b3@news.usenetexpress.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
X-Trace: individual.net jkyYiQN4QKsp+wEdjjOPJAiBuc7PZp5XPsXx6V8c6JwVG4+vQy
Cancel-Lock: sha1:qRZtcmfGBpeEirXno7uFZ+JSGEs= sha256:Qx77XF5VUSxAZ+PuoMPELdCvqB6843GNI/g4RYa5/yE=
X-No-Archive: Yes
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:91.0) Gecko/20100101 Firefox/91.0 SeaMonkey/2.53.18.2
In-Reply-To: <17de7c0ce189fbc8$526471$1616079$802601b3@news.usenetexpress.com>
Xref: csiph.com comp.os.linux.misc:56629

Lester Thorpe wrote:

>         Coordinate Transformation Matrix (157): 0.400000, 0.000000, 0.000000, 0.000000, 0.400000, 0.000000, 0.000000, 0.000000, 1.000000
[...]
> But what do the rest of the values accomplish?
>
> I can find no documentation on this issue.  If someone can
> provide links or a description it would be appreciated.

You cursor movement is the vector you get when you multiply the matrix
with the input vector:

/x'\       /x\
|y'| = M * |y|
\1 /       \1/

The third dimension allows merging every possible transformation into a
single multiplication:

https://en.wikipedia.org/wiki/Affine_transformation#Image_transformation