Cocktail game table in mirror mode - Need help setting up

lepingos

Hello to all.
English is not my native language. Sorry in advance if some explanations may be confusing :)

I have finalized a game table project in cocktail mode, and I am in the process of installing the game roms.

My configuration:

Rasperry PI 2 / 32GB
HP 19p screen
Updated to the latest version of retropie/retroarch (at 04-26-2020)

My problem is very simple,
I can not, despite my Google search, forum or other to configure the screen to be able to play two on my emulator
I don't know how to configure the emulator to split the screen vertically in half.

For the moment I am looking especially for MAME ROM like:
-Digdug2,

bobblebubble,

If you had directions or resources that allow me to easily set up this configuration it would be great

Thank you for your help.

IanDaemon

If you're using MAME2003 you should be able to open the MAME menu and there will be a dip switch setting for cabinet type with choices of "Upright" or "Cocktail". Not all games were originally sold as Cocktail cabinets. If the game natively supports this then you can just use the MAME menu. If the game doesn't natively support this then you'll have to use a shader to get close, but it may not be 100% what you want. (You can check out this shader: https://github.com/libretro/glsl-shaders/blob/master/misc/cocktail-cab-portrait.glsl)

I'm currently trying to find ROMs that natively support this and I'm keeping a list here: https://retropie.org.uk/forum/topic/25668/classic-cocktail-cabinet-games?_=1587907089489

My list is not all encompassing and I'm adding to it as I find games, but this is a start. I'm focused on the original "alternating gameplay". I'll try Dig Dug 2. Are you looking for simultaneous two-player games? Bobble Bobble definitely would be.

IanDaemon

@lepingos I just tried Dig Dug II and it natively supports the classic "upside down for second player" gameplay. Just set the cabinet type in the MAME menu with the dip switch. Restart the game. Viola. (restarting the game after each change)

lepingos

Thank you @IanDaemon

I will look at the list and your remarks in detail.
thanks again

theissdev

@lepingos I made something similar to this here: https://retropie.org.uk/forum/topic/23763/cocktail-cab-project?_=1588012689220

Think that split screen is what you're asking about. I did that w/ some custom shaders, slightly modified off the shaders available here: https://github.com/RetroPie/common-shaders/tree/master/misc

I've got 2 vertical split and 2 horizontally split shaders (normal and flipped (for the games that appear upside down when split)):

http://metalmutts.com/cab/cocktail-cab-portrait-flipped.glsl
http://metalmutts.com/cab/cocktail-cab-portrait-vert-flipped.glsl
http://metalmutts.com/cab/cocktail-cab-portrait-vert.glsl
http://metalmutts.com/cab/cocktail-cab-portrait.glsl

Drop those somewhere in your /opt/retropie/configs/all/retroarch/shaders dir. And then select them via the retroarch menu. Note that these require the retroarch emulators to be used ("lr-x").

These work w/ the screen size in retroarch set to the full monitor size. (0, 0, 1920, 1080 in my case.)

For any game that was 2p alternating and supported cocktail mode, I went with that instead of the split screen. The split screen is really for 2p simultaneous play.

Since the horizontal games when split fill the screen perfectly for me, I didn't have any artwork. The vertical games however leave some black space on the edges that since my cab is artwork-forward, I wanted to fill. If you're running the lr-mame2003plus (possibly lr-2003 vanilla as well - all my 2003 games are running in plus), you're able to support artwork w/ little to no slowdown. Look at my cab and see how galaga looks there (this was later changed when i enabled cocktail mode on galaga).

Here's my ikari artwork you can use as a template for vertical split screen games: http://metalmutts.com/cab/ikari.zip - it goes in ~/Retropie/BIOS/mame2003-plus/artwork

IanDaemon

Oh a split-screen display isn't a classic cocktail cabinet. It's more of an Arcade1Up "head-to-head" cabinet. From the photo and his mention of Dig Dug II (which supports the cocktail mode) . BUT the OP does mention "split the screen". I apologize.

theissdev

@IanDaemon No worries. It's looking good. Great job!

IanDaemon

I'm just waiting for gamers to visit and play this cabinet as 2p.