Help required with setting up my mouse as a lightgun within the opera-libretro (3DO) core of Retroarch

[St_Eddie]

Hi,

I'm struggling with attempting to use my mouse as a lightgun for the 3DO core of Retroarch.  The game I'm trying to achieve this with is StarBlade.  I've tried all sorts of combinations within Retroarch's port 1 and 2 control settings; for example, port 1 as a joypad and port 2 as a 3DO lightgun, or port 1 as the Arcade lightgun and port 2 as nothing.

However, the the main issue is that I'm able to achieve moving the on screen cursor with my mouse when setting port 1 as either the 3DO or Arcade lightgun (as well as having an on screen UI overlay cursor) but unable to use any of the mouse buttons.  Whereas, if I set port 2 as the lightgun, then I am able to use the mouse buttons in-game (including to shoot), but unable to alter my aim with the mouse (even the on screen UI cursor disappears)!  It's rather maddening.  I even tried to set both ports 1 and 2 as lightguns in the hope that it may create some kind of Frankenstienian monster, but sadly nothing seems to work.  I can only either shoot or move the reticle, but not both.

Any help would be greatly appreciated.  Thank you.

[MitchyB]

I had similar problem with Demolition Man in Opera-libretro, but I figured it out!  There is a core option called Active Input Devices that is set to 1 by default.  Set this to 2.  This may be all you need, but here's more info about my setup in case it's helpful.

Demolition man requires both a gamepad and light gun.  I setup the gamepad on port 1 and the light gun on port 2.  The catch is that RetroArch port 2 is not setup to read my mouse (and typically I wouldn't want it to).  My workaround solution for this is to setup RetroArch Port 5 (In Settings>Input>RetroPad Binds) as a mirror of Port 1.  I can't foresee myself playing a 5-player game in RA so I don't need Port 5 for an actual 5th input.  Port 5 now receives my gamepad-1 input as well as mouse and keyboard input for light guns.  Now back in Quick Menu>Controls>Port 5 Controls, I have Device Type set to 3DO Lightgun and Mapped Port set to 2.  Demolition Man now works great!

This Port 5 trick is helpful in other cases too, like older games that support a single player using 2 controllers.  Perfect Dark on N64 is a good example.  In-game, I can set the options for dual-controller mode, set Port 5 Controls>Mapped Port to 2, and I can play the game with my XBox controller in twin-stick mode like a modern FPS.  Some input customization is needed, but that's all saved in my per-game config and it doesn't affect regular N64 games.