How Do I Get RetroArch to See Two Mouse Devices?

Tango · 18 March 2020 01:51

I’ve asked about this under Linux, but after 5 days, there are no responses, even after I asked if there was something confusing about my post that I should fix.

I am using RetroPie on a Raspberry Pi 3B+ and have a trackball and spinner connected via USB. Earlier I had those and a mouse connected. I found that no matter what I did, even after verifying everything worked, I cannot get RetroArch to see more than one mouse device.

When I had the mouse plugged in, it would see the mouse (at /dev/input/mouse1 - forgot what event node it was attached to). When I unplugged it and had just the trackball and spinner plugged in, it would see just the trackball and is totally unaware of the house.

My mouse is at /dev/input/mouse0 and /dev/input/event3. The spinner is at /dev/input/mouse1 and /dev/input/event6. If I set input_player1_mouse_index to 0, then when I try any games, I can use the trackball. If I set it to something else, then the trackball doesn’t work and neither does the spinner. I’ve tried setting the index to 0,1,3, and 6 - to cover the input and event nodes. No matter what, no games that use RetroArch ever see the spinner.

I have read about having two mouse devices on at once, but most of that seems to be about using 2 light guns at a time.

I don’t need to have the trackball and spinner both work in the same game at once, I just need one at a time.

How can I get RetroArch to see the spinner as well as seeing the trackball?

hunterk · 18 March 2020 03:04

Usually no response means nobody has an answer for you, rather than there being something wrong with your question.

In this case, I think multiple mice go to different ports:

github.com

libretro/RetroArch/blob/master/input/drivers/udev_input.c#L234


   udev_input_mouse_t *mouse = NULL;


   if (port >= MAX_USERS || !video_driver_has_focus())
      return NULL;


   for (i = 0; i < udev->num_devices; ++i)
   {
      if (udev->devices[i]->type == UDEV_INPUT_KEYBOARD)
         continue;


      if (mouse_index == settings->uints.input_mouse_index[port])
      {
         mouse = &udev->devices[i]->mouse;
         break;
      }


      ++mouse_index;
   }


   return mouse;
}

That is, I think each port can only have 1 mouse attached at a time.

Tango · 18 March 2020 03:41

Thanks! Each forum seems to be a bit differently and I know sometimes when I’m sorting through things, I can type up a mess, so I do like to find out if I was just confusing.

In RetroArch, the trackball is under Port 1 Binds and the spinner is under Port 2 Binds.

In one place I read that the mouse index should be set to the event index (/dev/input/eventX) but I find the mouse works when I point it to the mouse node (/dev/input/mouse0). So I have input_player1_mouse_index=0 in retroarch.cfg. I’ve changed that index to 1 and 6. (The spinner is on mouse1 and event6.) No luck.

Am I right in thinking that I should set the mouse index in Port 1 Binds to 0 (for the trackball) and set Port 2 binds to 1 (for the spinner)? And if that’s the case, is there something else I need to do to say, “The mouse is on Port 2?”

hunterk · 18 March 2020 03:47

So, if you go to port 2 binds, what’s its mouse index set to? Can you manually swap them there in the menu?

Tango · 18 March 2020 04:07

On Port 2 Binds, the mouse is set to 1.

I can and have swapped them. I’ve tried 0, 1, 3, and 6 for the binds.

(Remember, 0 & 1 for /dev/input/mouseX, 3 & 6 for /dev/input/eventX.)

I’ve just realized that what I did NOT do is make sure that whatever I set for Port 1 was NOT duplicated in Port 2. I can try that. (Side note: The arcade machine is in a guest house, computer is in the house. So sometimes I can get there quickly with ssh, but other times, especially when it’s a cold night, I’m likely not to get to the guest house, which is about a 2 football field walk away, until the next day.)

Tango · 21 March 2020 19:30

Finally got it working, as I posed this thread:

GOT IT!

And it makes no sense to me at all.

Again, here’s what I have:

/dev/input/mouse0: Trackball /dev/input/mouse1: Spinner

And that’s IT for /dev/input/mouseX. If X > 1, the device node just doesn’t exist.

Under events:

/dev/input/event3 = Trackball /dev/input/event6 = Spinner

When I tried cat /dev/input/eventX with event ≠ 3 or 6, I got no input at all from the trackball or spinner.

So when I was in Port 1 Binds, I’d set the Mouse Index to 0, 1, 3, & 6. I’ve seen documentation that says that it’s the event, not the mouse node that matters. But only 0 would work with the trackball. All other numbers would NOT work.

I had, previously, when I had a mouse hooked up (and, I think, when I was using the older version of RetroPie), tried running through 0-10 for Mouse Index in RGUI and got nothing. ONLY 0 would work, and only with the trackball.

But today I tried, almost by accident, using 2 for the Mouse Index and the spinner worked!

I don’t see why. I have mouse0 and mouse1. The only events that showed any input for the mouse devices were 3 & 6, and only when I tested them with cat /dev/input/eventX, and not with RetroArch at all.

I’m wondering if there could be a bug with the Mouse Index numbers in RetroArch. I would think the Mouse Index would be the same number as the mouse device node or the event node. Or that the index would not skip over a blank. (In this case, it skips 1 - go from 0 for trackball to 2 for spinner.)

So it works. If possible, I’d like to know why, but I’m just glad I got it working. There’s other alterations I want to make to my config, but I didn’t want them to get in the way of this issue, so I’ve waited to do them.

This also provides support for the answer to one of my questions: I used Port 1 for almost everything and Port 2 for the spinner, so that’s proof that the virtual pad for Player 1 can use devices from ports other than 1.