Pre-Brewing Event

[Azaka7]

Note: I've already written and submitted a PR for this.

 

I would like an event that allows modders to check alter the contents of a brewing stand before the actual brewing takes place. The brewing event that already exists only takes place after vanilla brewing and the ingredient is removed.

 

This event would basically allow for the adding of custom brewing recipes and alter existing recipes. Here's an example mod:

 

 

package examplemod.common;

import net.minecraft.init.Blocks;
import net.minecraft.init.Items;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.nbt.NBTTagList;
import net.minecraft.potion.Potion;
import net.minecraft.potion.PotionHelper;
import net.minecraftforge.common.MinecraftForge;
import net.minecraftforge.event.brewing.PotionBrewedEvent;
import cpw.mods.fml.common.Mod;
import cpw.mods.fml.common.Mod.EventHandler;
import cpw.mods.fml.common.event.FMLPreInitializationEvent;
import cpw.mods.fml.common.eventhandler.SubscribeEvent;

@Mod(modid = "brewing_example", name = "Brewing Example", version = "0.0.0")
public class BrewingExampleMain {
    @EventHandler
    public void preinit(FMLPreInitializationEvent event)
    {
        Item.getItemFromBlock(Blocks.piston).setPotionEffect(PotionHelper.blazePowderEffect);
        MinecraftForge.EVENT_BUS.register(this);
    }
    
    @SubscribeEvent
    public void handleBrewing(PotionBrewedEvent.Pre event){
        if(event.brewingStacks[3] != null){
            ItemStack jumpyPot = new ItemStack(Items.potionitem, 1, 8194);
            jumpyPot.stackTagCompound = new NBTTagCompound();
            jumpyPot.stackTagCompound.setTag("CustomPotionEffects", new NBTTagList());
            NBTTagCompound jumpyEffect = new NBTTagCompound();
            jumpyEffect.setByte("Id", (byte) Potion.jump.id);
            jumpyEffect.setByte("Amplifier", (byte) 4);
            jumpyEffect.setInteger("Duration", 1000);
            jumpyPot.stackTagCompound.getTagList("CustomPotionEffects", 0).appendTag(jumpyEffect);
            boolean flag = false;
            for(int i = 0; i < 3; i ++){
                if(event.brewingStacks[i]!= null && event.brewingStacks[i].getItem() == Items.potionitem && event.brewingStacks[i].getItemDamage() == 16){

                    if(event.brewingStacks[3] != null && event.brewingStacks[3].getItem() == Item.getItemFromBlock(Blocks.piston)){
                        event.brewingStacks[i] = jumpyPot;
                        flag = true;
                    }
                    
                    //Other ingredient checks can occur.
                }
            }
            if(flag){
                event.brewingStacks[3].stackSize -= 1;
                if (event.brewingStacks[3].stackSize <= 0)
                {
                    event.brewingStacks[3] = null;
                }
                event.setCanceled(true);
            }
        }
    }
}

 

 

This example mod would allow players to brew Jumping potions with Jump Boost (Amplitude 4 and Duration 1000) by brewing a piston into up to 3 awkward potions. The only problem I've encountered is that non-vanilla ingredients aren't normally allowed in the ingredient slot, so they have to be given a fake potion effect string (I applied the blaze powder string to the piston in this case).

 

What this mod is doing is checking the slots for appropriate contents, then replacing the potions and reducing the ingredient stack is brewing occurs.

 

Potion effects added by mods could be used in the brewed potion ItemStacks instead of a vanilla one, allowing mods to add brewing recipes for their own potion effects.

 

I know this all can be achieved by reflection, but if any two mods take up the same brewing recipe identification (same bits used for metadata) they will be incompatible. This event will allow for near complete compatibility between mods adding brewing recipes using this event.