[1.12.2] Adding Loot to Everything

[HalestormXV]

public class LootTableHandler
{
    public static final ResourceLocation CULTIST = LootTableList.register(new ResourceLocation(Reference.MODID, "cultist"));


    private static LootEntry scryingOrb = new LootEntryItem(ItemInit.ITEM_SCRYING_ORB, 30, 15, new LootFunction[0], new LootCondition[0], Reference.MODID+":loot_scrying_orb");
    private static LootEntry basicEssence = new LootEntryItem(ItemInit.RUNE_ESSENCE, 20, 10,new LootFunction[0], new LootCondition[0], Reference.MODID+":loot_basic_essence");

    @SubscribeEvent
    public void onLootTableLoad(final LootTableLoadEvent event)
    {
        if(event.getName().equals(LootTableList.CHESTS_SIMPLE_DUNGEON)) { event.getTable().getPool("main").addEntry(scryingOrb); }
        if(event.getName().equals(LootTableList.getAll())) {event.getTable().getPool("main").addEntry(basicEssence);}
    }
}

 

Specifically talking about the yellow lines. I am imagining the .getAll() literally will add this to everything, which is fine and intentional. At the top where I am creating the entry I'm just curious as to what the "qualityIn" refers to (third param of the LootEntryItem).

[jabelar]

I don't think it would work that way. Isn't getAll() returning a Set? How would the getName() of the event (which returns a ResourceLocation) ever equal a set of loot entries?

 

If you want to check against all, you will have to iterate (loop) through the set and check the resource location of each entry against the resource location for the event.

 

However I'm not sure that you need to do that either because I think the event is called for every loot table. So I think you would just go ahead and add your loot without any checking for equal.

[HalestormXV]

4 hours ago, jabelar said:

I don't think it would work that way. Isn't getAll() returning a Set? How would the getName() of the event (which returns a ResourceLocation) ever equal a set of loot entries?

 

If you want to check against all, you will have to iterate (loop) through the set and check the resource location of each entry against the resource location for the event.

 

However I'm not sure that you need to do that either because I think the event is called for every loot table. So I think you would just go ahead and add your loot without any checking for equal.

What do you suggest may be a simple way to do that? Im hoping I dont have to generate a whole list and such. I'd imagine this would be built in?

Edited March 25, 2018 by HalestormXV

[jabelar]

1 hour ago, HalestormXV said:

What do you suggest may be a simple way to do that? Im hoping I dont have to generate a whole list and such. I'd imagine this would be built in?

 The event is going to be called for each separate loot table. The event doesn't fire just once, it fires for every single JSON. So you don't need to "get all". You just need to add your loot to the table that is currently being handled and that will automatically get them all.

[HalestormXV]

35 minutes ago, jabelar said:

 The event is going to be called for each separate loot table. The event doesn't fire just once, it fires for every single JSON. So you don't need to "get all". You just need to add your loot to the table that is currently being handled and that will automatically get them all.

Oh I see, sorry I misunderstood you. So your basically just suggesting:

 


    private static LootEntry scryingOrb = new LootEntryItem(ItemInit.ITEM_SCRYING_ORB, 30, 15, new LootFunction[0], new LootCondition[0], Reference.MODID+":loot_scrying_orb");
    private static LootEntry basicEssence = new LootEntryItem(ItemInit.RUNE_ESSENCE, 20, 10, new LootFunction[0], new LootCondition[0], Reference.MODID+":loot_basic_essence");

    @SubscribeEvent
    public void onLootTableLoad(final LootTableLoadEvent event)
    {
        if(event.getName().equals(LootTableList.CHESTS_SIMPLE_DUNGEON)) { event.getTable().getPool("main").addEntry(scryingOrb); }
        
        event.getTable().getPool("main").addEntry(basicEssence);
    }
}

I'd imagine? And if so that being said what does the "qualityIn" refers to (third param of the LootEntryItem).

Edited March 25, 2018 by HalestormXV

[jabelar]

Yes, that code looks correct if you want to add basicEssence to every table and add scryingOrb only to the simple dungeon chest.

 

6 hours ago, HalestormXV said:

what does the "qualityIn" refers to (third param of the LootEntryItem).

 

Well, to figure that sort of thing out you should look at the source code. I did and found that it is a multiplier on the luck that is used to adjust the "weight" of the loot entry. You can see for yourself if you look at the implementation of the getEffectiveWeight() method in the LootEntry class.

[HalestormXV]

21 hours ago, jabelar said:

Yes, that code looks correct if you want to add basicEssence to every table and add scryingOrb only to the simple dungeon chest.

 

 

Well, to figure that sort of thing out you should look at the source code. I did and found that it is a multiplier on the luck that is used to adjust the "weight" of the loot entry. You can see for yourself if you look at the implementation of the getEffectiveWeight() method in the LootEntry class.

Finally managed to get to testing this piece and it appears the above code segment crashes:

https://pastebin.com/XN3CtnS1

 

Its throwing a null. Perhaps the LootPool is not named "main." not sure if the caps matter with the LootTables or not or if it is just a separate name? The crash triggers when attempting to log into the world. So I know it is not a registration issue.

[jabelar]

35 minutes ago, HalestormXV said:

Finally managed to get to testing this piece and it appears the above code segment crashes:

https://pastebin.com/XN3CtnS1

 

Its throwing a null. Perhaps the LootPool is not named "main." not sure if the caps matter with the LootTables or not or if it is just a separate name? The crash triggers when attempting to log into the world. So I know it is not a registration issue.

 

As always, don't just speculate -- actually trace through the execution to see what is happening. Either use debugger mode or console (System.out.printf()) statements to see what is going on. For example, you see which loot table is actually being loaded for the event and then you can inspect that table to understand if there is a different pool name.

 

Technically if you look at the LootTable$Serializer class you'll see that the name is extracted using the ForgeHooks.readPoolName() method. In that method, there are various cases where the pool could be named in the actual JSON, but if not then it is according to the following return statement:

 

return ctx.poolCount == 1 ? "main" : "pool" + (ctx.poolCount - 1);

 

So that means that it could be named "main" but could also be named "pool0", "pool1", etc. And it could also have a custom name if the "name" is assigned in the JSON (although looking through the vanilla loot table JSONs I don't think it is used there).

 

So now that I think about it, if you want to add your loot to every pool in every loot table you would really want to access the pools field in the loot table. The problem though is that it is private and does not seem to have a "getter" method. Therefore, I think you need to use Java reflection to make the pools List accessible, and then you should iterate through that list and add your item.

 

Now that I think about it, it is kinda lame that loot table pools list is private. Maybe I'm missing something, but it seems to me that it could be useful. Otherwise you need to know (or guess) at the pool names.

 

If you want to handle the vanilla pools, then you can probably not use reflection but rather just "guess" at the names since you know that they will either be "main" or "pool0", "pool1", etc. So you can create a loop that tries to get each of those pools and checks if it is null and escapes the loop once it runs out of possible pool names.

[HalestormXV]

On 3/26/2018 at 11:40 PM, jabelar said:

 

As always, don't just speculate -- actually trace through the execution to see what is happening. Either use debugger mode or console (System.out.printf()) statements to see what is going on. For example, you see which loot table is actually being loaded for the event and then you can inspect that table to understand if there is a different pool name.

 

Technically if you look at the LootTable$Serializer class you'll see that the name is extracted using the ForgeHooks.readPoolName() method. In that method, there are various cases where the pool could be named in the actual JSON, but if not then it is according to the following return statement:

 

return ctx.poolCount == 1 ? "main" : "pool" + (ctx.poolCount - 1);

 

So that means that it could be named "main" but could also be named "pool0", "pool1", etc. And it could also have a custom name if the "name" is assigned in the JSON (although looking through the vanilla loot table JSONs I don't think it is used there).

 

So now that I think about it, if you want to add your loot to every pool in every loot table you would really want to access the pools field in the loot table. The problem though is that it is private and does not seem to have a "getter" method. Therefore, I think you need to use Java reflection to make the pools List accessible, and then you should iterate through that list and add your item.

 

Now that I think about it, it is kinda lame that loot table pools list is private. Maybe I'm missing something, but it seems to me that it could be useful. Otherwise you need to know (or guess) at the pool names.

 

If you want to handle the vanilla pools, then you can probably not use reflection but rather just "guess" at the names since you know that they will either be "main" or "pool0", "pool1", etc. So you can create a loop that tries to get each of those pools and checks if it is null and escapes the loop once it runs out of possible pool names.

Im imagining ReflectionHelper.getPrivateField would likely be the route to go with this? I've never actually utilized the reflection helper before nor can I Really find any documentation on it.

[jabelar]

22 minutes ago, HalestormXV said:

Im imagining ReflectionHelper.getPrivateField would likely be the route to go with this? I've never actually utilized the reflection helper before nor can I Really find any documentation on it.

It is actually fairly easy actually. Regular Java reflection is well documented so you can find tutorials, but in modding it is a bit tricker because you need to be able to have the reflection work both in the development and final build environments. So ReflectionHelper does reflection but helps map it to both situations by passing both the debfuscated and SRG names to the methods.

 

The idea generally is to store the reflected field or method in an instance, For example to access the "fire" field in Entity class something like:

public static Field fire = ReflectionHelper.findField(Entity.class, "fire", "field_190534_ay");

Then if I wanted to access it to get or set the value I might do something like:

           if (theEntity.isImmuneToFire())
           {
               fire.setInt(theEntity, fire.getInt(theEntity) - 4);
               if (fire.getInt(theEntity) < 0)
               {
                  theEntity.extinguish();
               }
          }

 

The only trick is that in the ReflectionHelper you can see I entered both the string "fire" and "field_190534_ay". To find that second string you need to use the MCPBot (or download the MCP mappings and search through them to find the right one).