[Script] How to make the Zigzagoon battle a double battle?

[TikTyke]

I am new to decomp hacking and have been using the Pokeemerald battle engine expansion. I would just like to know how to make the battle with Zigzagoon after choosing your starter into a double battle.

 

[Lunos]

I am new to decomp hacking and have been using the Pokeemerald battle engine expansion. I would just like to know how to make the battle with Zigzagoon after choosing your starter into a double battle.

By the looks of it, you'll want to write code inside of CB2_InitBattleInternal that sets the main callback to CB2_HandleStartMultiBattle, if (gBattleTypeFlags & BATTLE_TYPE_FIRST_BATTLE).

You may also want to update SetUpBattleVarsAndBirchZigzagoon.
Since you'd be triggering a double battle, you'll have to set up a Pokémon in the 2nd slot of the enemy party.

I may be missing some stuff since I only took a glance at the code and never tried to do this myself.
If someone reads this and wants to chime in to correct me and/or expand on this, feel free to.

 

[TikTyke]

Thanks for the response!

I've created a Pokémon for the 2nd slot of the enemy party but it is still a single battle (even when I have two Pokémon on my team).

I added the lines

else if (gBattleTypeFlags & BATTLE_TYPE_FIRST_BATTLE)
        SetMainCallback2(CB2_HandleStartMultiBattle);

into CB2_InitBattleInternal but I'm not sure if that is doing what I want it to do, if anything at all.

 

[Lunos]

Thanks for the response!

I've created a Pokémon for the 2nd slot of the enemy party but it is still a single battle (even when I have two Pokémon on my team).

I added the lines

else if (gBattleTypeFlags & BATTLE_TYPE_FIRST_BATTLE)
        SetMainCallback2(CB2_HandleStartMultiBattle);

into CB2_InitBattleInternal but I'm not sure if that is doing what I want it to do, if anything at all.

Okay, I just ended up looking into it myself rather than going blind.
Here's the diff.