Re: [AD] Various tangents to distinguishing keyboards

[Edgar Reynaldo <edgarreynaldo@xxxxxxxxxxxxxxxxxx>]

On 9/27/2017 5:55 PM, S. J. Dobrowolski wrote:
> Grettings, everyone.
>
> Apologies if this is the wrong channel but it relates to source code 
> of Allegro so I couldn't come up with anything more appropriate. 
> (Also, please excuse any English errors.) I was considering modifying 
> A5 for multiple mice and keyboards event input support - while 
> distinguishing these devices, for clarity. Rationale: some of my 
> friends and me don't like gamepads that much, but like the idea of 
> local play with separate controllers. As a sidenote, I guess I'm more 
> familiar with using A4, but my prototypes could use a rewrite, even if 
> it means coding from scratch where I have used A4 bitmaps for game logic.
>
> Based solely on web searches, on Windows, it appears some sort of 
> hardware ID is part of "raw input" API event. On Linux, it appears 
> that evdev API allows you to distinguish connected devices, but I'm 
> not sure how that is supposed to cooperate with various layers of user 
> protection and desktop stack. On MacOS... I frankly couldn't find good 
> information. I don't have a Mac anyway, so trusting my Mac code even 
> in the slightest would be a huge mistake.

You are correct, on Windows the key is to use the RawInput API from Win32.

I have some experience with this subject, as I wrote a Multi Mouse 
software interface library and program called ManyMouse. I spent an 
entire summer doing this as my research project. You can see the current 
state of the program on Github here :

https://github.com/EdgarReynaldo/ManyMouse

The file you will find most interesting is RawInputHandler.cpp, here : 
https://github.com/EdgarReynaldo/ManyMouse/blob/master/src/RawInputHandler.cpp

The biggest problem with this project is interacting with the OS. It's 
easy to monitor HID devices and multiple mouse input. The problem comes 
when you want them to act like mice cursors. You have to create your own 
window for the mouse icon, you have to make it transparent, and the hard 
part is taking mouse input and making it into window actions.

I abandoned this project a while back, and I've been busy with other 
things. You're welcome to look at the source code and ask questions, but 
this is still a big project for a novice to take on. Windows OS just 
does not support multiple mice cursors, period. You have to emulate 
every little thing they do, like sending mouse pressses to the correct 
window, and that means you have to read the windows on the desktop, and 
that means a ton of os and system windows and tons of nested child 
windows and controls and it is a nightmare. That's why I abandoned this 
project.

I would have to separate out and rewrite pretty much everything for it 
to be usable by allegro and integrate it with the library.

My 2c

Edgar