Bug 66134

Summary:	Getting/setting the DPI of the mouse
Product:	xorg	Reporter:	sworddragon2
Component:	App/xinput	Assignee:	Xorg Project Team <xorg-team>
Status:	RESOLVED FIXED	QA Contact:	Xorg Project Team <xorg-team>
Severity:	enhancement
Priority:	medium	CC:	peter.hutterer
Version:	7.7 (2012.06)
Hardware:	All
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:

Description sworddragon2 2013-06-24 20:08:18 UTC

I'm using xinput 1.6.0 and want to try to set the same mousespeed independent of the used mouse. If I'm knowing the DPI of the mouse I need just to change the value of "Device Accel Constant Deceleration" to achieve this. But there are 2 problems:

1. Values below 1 on "Device Accel Constant Deceleration" are not possible. For example a mouse with 400 DPI can't be set to the speed of a mouse with 800 DPI.

2. If the DPI value of the mouse is unknown to the user he can't set "Device Accel Constant Deceleration" to get a consistent speed.


Ideally xinput would provide a way to set the DPI directly. At least it would be nice if xinput would show the DPI of the mouse and if "Device Accel Constant Deceleration" could be set to values below 1 to increase the speed.

Comment 1 Peter Hutterer 2013-07-14 10:38:21 UTC

(In reply to comment #0)
> 1. Values below 1 on "Device Accel Constant Deceleration" are not possible.
> For example a mouse with 400 DPI can't be set to the speed of a mouse with
> 800 DPI.

I'll look at that to see if we can set a value for 0-1 to speed things up.

> 2. If the DPI value of the mouse is unknown to the user he can't set "Device
> Accel Constant Deceleration" to get a consistent speed.

we don't get the resolution for relative axes from the kernel (if we do, let me know because I'm not aware of it) so this is a larger change. If other (non-Linux) kernels provide this information we'll need to update the drivers. The XI2 protocol supports resolution for relative devices, something needs to set it though.

Comment 2 Peter Hutterer 2013-07-15 04:09:46 UTC

http://patchwork.freedesktop.org/patch/14056/

Comment 3 Peter Hutterer 2013-07-17 04:54:37 UTC

commit 74469895e39fa38337f59edd64c4031ab9bb51d8
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Mon Jul 15 13:06:28 2013 +1000

    dix: allow a ConstantDeceleration between 0 and 1 (#66134)

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