[garbear]

Related to the number of players, has any thought been given to how handling the various multi-tap devices could be done? The problem with a lot of them is that they aren't really well handled by games not specifically written to use them, so you can't just set the core to behave like it has them attached all the time, it would need to have a DB of how many players a game supports and which multi-tap the core needs to be using. Gens Plus GX has at least 3 possible adapters IIRC, two for the Mega Drive and one for the Master System. The two Mega Drive ones are supported by different selections of games too to further confuse the issue.

Nope, multitap is a problem. Libretro doesn't even give us a way to check the number of players regardless of multitap. bNES used to crash when you told it a third controller was plugged in. Ideally this should be handled by core, because many people were not around when the NES was released (me!) and are unfamiliar with multitap devices.

Anything that requires a game DB has to be put on hold, unfortunately. Our current messy DB situation is really killing us, so we'll need ideas that work without a game DB for the time being.

The only thing that matters is the number of players, and this is mostly also only relevant during a gaming session and might not have to be a global setting.

understood

• launch a game and bring up OSD which has a button to manage the players
  

grumpygamer has posted some ideas:

What do you think of these?

• in that dialog you should be able to specify the number of players and specify the player profile to use or just make it a guest
  
• a player profile consists of the name, an avatar and the preferred and custom button mappings/layouts for each game/emulator

For this, we'll need player profiles. Names are tricky, because we have to assume a remote or keyboard. We could do generic "Player 1", "Player 2", with an option to customize. Or we could be awesome and use a name generator like this metal gear solid one.

A good avatar would be the controller used by that player. However, as we know, this is too difficult to figure out ATM. Instead, we could use a single generic gamepad for all players, autogenerate avatars, or create "avatar resource add-ons" and let the user choose from a small list of included avatars. Which idea do you like the best?

• once a player profile is assigned (or guest mode is used), input devices have to be assigned to specific players. This should be done by auto-detection, which means, once the button "select input device" is clicked, a dialog pops up that asks the player to press any button on the input device he'll be using in this session (controller, keyboard, smartphone via event server/json API, ...)
  

Good flow, I like this.

• once the type of input device is selected, the user can choose from predefined button layouts for his input device (like "WASD" or "cursors" for keyboards, style A, B, C for controllers etc) or create a custom one which triggers our mapping dialog with the currently emulated console preselected (or only that console). In case it's a known profile from the DB, the last used mapping will automatically be applied
  

The global/generic mapping window/section that we have right now should become a section where users can manage their button presets per console and device. So when you select a certain console you first see the list of available button presets along with the input device they belong to (or grouped by device type/family). Then you can modify, rename or delete existing ones or create new mapping and specify which of them should be the default one (like for new/guest players).

Presets would be nice. For controllers, we could offer "Physical", "Logical" and "Custom" options (physical maps 360 A to SNES B, logical maps 360 A to SNES A). We're still starved for button map data, but that should be fixed over time.

For keyboards, we should offer "Keyboard WASD" and "Keyboard Arrows", but remember that some controllers and arcade sticks use keyboard drivers. For example, my X-Arcade Tankstick has a keyboard profile for player 1 and player 2. We'll need to show "X-Arcade Tankstick P1" and X-Arcade Tankstick P2" in the list as well. So the list could get quite long.

The basic concept works just fine if every player is initially treated as "guest" - so the profile stuff could be added any time later.

Sounds good, I think this is a good way to start.