HACKER Q&A
📣 _fw

Why don't we use two mice at once?


I always wondered why two mice aren’t an option for the vast majority of operating systems. Imagine how fast one could operate a computer with two cursors, clicking on one part of the UI while moving their mouse to the next.

I understand adding support for two cursors at the OS level might be tricky, but how hard can it be?

What are your thoughts?


  👤 omgbear Accepted Answer ✓
I'd love my trackpad and mouse be separate -- It'd be nice to have the trackpad maybe constrained to the laptop screen and the mouse cover both the built-in and external one.

Maybe possible with XINERAMA and assigning a mouse to a separate screen? IIRC you could have two separate X sessions on one machine with separate mice/keyboard -- Never tried to have 2 cursors in one screen.


👤 syndicatedjelly
People typically use a mouse with 2 digits (pointer finger and middle finger). Motion is captured in 2 dimensions. Toss in a scroll wheel an extra thumb button and that’s about 6 different inputs.

2 mice could theoretically be 12 different inputs.

The inputs aren’t evenly distributed though, in terms of ease of access. The function of the left click button isn’t swappable with the x-axis of the trackball, for example.

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Now compare that with the keyboard. A keyboard with just 3 rows of 10 keys each is 30 different inputs already. Each input is fairly easy to swap - any finger can (relatively) easily hit any key, regardless of function. The only exception is the x-y motion of the trackball.

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So it seems logical that the best option would be the combination of a mouse and a huge number of keys.


👤 torunar
It’s possible to use multiple mice simultaneously in Linux using xinput: https://github.com/torunar/double-mouse.sh/blob/main/double-...

👤 jjackson5324
A better solution would be to use the webcam to track what a user is looking at and just immediately move the pointer to that location.

👤 themerone
I expect that most people would struggle to interact with two sections of the screen at once.

👤 nathants
i tried a two mouse setup for a game i’m building, but went back to one. left hand on half a keyboard is just a really good interface, and i already have one mouse.

i could see it working for a flight sim though. dual joysticks.


👤 AlgoRitmo
i’m not ambidextrous

👤 bdangubic
you are thinking about this the wrong way - the question you should be asking yourself is why do you need a mouse at all in 2024… it’s been 65 years since mouse was invented…