Add support for the official 3-buttons controller (NEC Avenue Pad 3)

[Steveneska]

Referencing issue #48 that seem to have not been commented on, and taking from this forum post, 3-buttons controller like the NEC Avenue Pad 3 allows the player to map either the Select or Run button (with the toggle of a switch) to a third action button (button III in this case). It is very useful for games that mapped controls besides menus to the run or select button. These games stand to benefit greatly from the addition of the NEC Avenue Pad to the Beetle PCE core. Below is a list of them and how they map a thrid action to the Run/Select buttons:

1. Forgotton Worlds - The only game that requires a 3-buttons controller: maps movement to the Select button
2. After Burner II - Maps the afterburners to the Run button
3. Air Zonk - The Select button fires up rear thrusters to damage enemies behind you
4. Atlantean - Warps by pressing the Run button
5. Akumajou Dracula X: Chi no Rondo - Maps item crush to the Select button
6. Barunba - The Select button rotates your cannons
7. Battle Royale - Select + D-pad unleash a special attack
8. Blazing Lazers - The Select button cycles through your speed settings
9. Bloody Wolf - The Run button throws grenades or flash bombs, uses flamethrower and dismounts motorcycles
10. Cyber Core - The Select button cycles your speed settings
11. Download - The Select button cycles your speed settings
12. Kunio Soccer -
13. Final Match Tennis - Maps the lop shot to the Run button
14. Final Soldier - The Select button cycles through your speed settings
15. Gate of Thunder - The Select button cycles through your speed settings
16. Golden Axe - The Select button casts magic
17. Gradius II - The Select button uses power ups
18. John Madden Fooball - The Run button button passes
19. Legendary Axe 2 - The Run button throws bombs
20. Martial Champion - The Run button attacks high
21. Metamor Jupiter - The Select button cycles through ship transformations
22. Ninja Spirit - The Select button changes weapons
23. Riot Zone - The Run button uses desperation move
24. Silent Debuggers - The Run button fires secondary weapon
25. Shinobi - The Select button uses ninja magic
26. Soldier Blade - The Select button cycles through your speed settings
27. Special Criminal Investigation - The Select button uses boost
28. Spriggan mk 2 - The Select button toggles through weapons
29. Street Fighter II' - The Run button is your third attack, the Select button cycles between punches and kicks
30. Star Soldier - The Select button cycles through your speed settings
31. Turrican - The Select button changes weapons
32. Vallis III - The Run button changes characters
33. World Heroes 2 - The Run button is your throw/taunt button

[bslenul]

Not sure to see the benefit of adding this, if button III only acts as a duplicate of Select or Run with that controller, then why not simply rebinding a button to Select/Run?

Like if I want I, II and III on my Circle, Cross and Square buttons with III acting as Run, I'll just rebind my Square button to Run.

Or I misunderstood what you're trying to suggest.

[Steveneska]

I'm currently rebinding buttons as well as a trick. The idea was for less experienced users to have the simplicity to just select a controller type and jump into the game, which I believe most people still want to do when they fire up a Libretro front-end, but I get your point. In any case, if it's too much hassle to add a 3 buttons controller or if it's not a priority at this time, I would understand.