[1.8] Changing Vanilla Block Issues

[Zetal]

Hey guys,

 

I've been trying to make it so that a player can move through leaves and climb logs like a ladder if and only if the player climbing it is a certain class and level (using other stuff, don't worry about it) which worked great back when I was doing core mods, but I've seen the light and I'm now trying to update my mods for 1.8 using no core mods whatsoever. It's been pretty smooth sailing for the most part thanks to some of the new hooks that have been introduced, but I can't seem to think of a clever way to make the leaves and logs behave the way that I want them to.

 

Obviously there are some hackish workarounds, such as hijacking the world gen completely and replacing all trees with my custom logs and leaves, but, not wanting to have to do something so extreme, I decided to take a look at ASM and see if I could just replace the blocks at the source.

It hasn't been going that great. After some google searching I found an old topic for 1.7.2 with an easy-to-use method that they said worked. I copied it in, fixed up the errors, and it seems to work great right up until the game crashes.

 

Debug shows that the blocks are successfully replaced with my new ones, but the game then promptly crashes because "availabilityMap references empty entries for id 198." which seems odd to me since I don't actually touch id 198 but what do I know.

 

Full error:

 

java.lang.IllegalStateException: availabilityMap references empty entries for id 198.

at net.minecraftforge.fml.common.registry.GameData.testConsistency(GameData.java:903)

at net.minecraftforge.fml.common.registry.GameData.freezeData(GameData.java:625)

at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:698)

at net.minecraftforge.fml.client.FMLClientHandler.finishMinecraftLoading(FMLClientHandler.java:291)

at net.minecraft.client.Minecraft.startGame(Minecraft.java:484)

at net.minecraft.client.Minecraft.run(Minecraft.java:325)

at net.minecraft.client.main.Main.main(Main.java:117)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)

at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

at net.minecraftforge.gradle.GradleStartCommon.launch(Unknown Source)

at GradleStart.main(Unknown Source)

 

 

A detailed walkthrough of the error, its code path and all known details is as follows:

---------------------------------------------------------------------------------------

 

-- Head --

Stacktrace:

at net.minecraftforge.fml.common.registry.GameData.testConsistency(GameData.java:903)

at net.minecraftforge.fml.common.registry.GameData.freezeData(GameData.java:625)

at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:698)

at net.minecraftforge.fml.client.FMLClientHandler.finishMinecraftLoading(FMLClientHandler.java:291)

at net.minecraft.client.Minecraft.startGame(Minecraft.java:484)

 

 

My code:

 

public static boolean replaceBlock(Block toReplace, Class<? extends Block> blockClass)

{

Field modifiersField = null;

try

{

modifiersField = Field.class.getDeclaredField("modifiers");

modifiersField.setAccessible(true);

 

for (Field field : Blocks.class.getDeclaredFields())

{

if (Block.class.isAssignableFrom(field.getType()))

{

Block block = (Block) field.get(null);

if (block == toReplace)

{

String registryName = ((ResourceLocation) Block.blockRegistry.getNameForObject(block)).getResourcePath();

int id = Block.getIdFromBlock(block);

ItemBlock item = (ItemBlock) Item.getItemFromBlock(block);

System.out.println("Replacing block - " + id + "/" + registryName);

 

Block newBlock = blockClass.newInstance();

FMLControlledNamespacedRegistry<Block> registry = GameData.getBlockRegistry();

Block.blockRegistry.register(id, new ResourceLocation("minecraft", registryName), newBlock);

 

Field map = RegistryNamespaced.class.getDeclaredFields()[0];

map.setAccessible(true);

((ObjectIntIdentityMap) map.get(registry)).put(newBlock, id);

 

map = FMLControlledNamespacedRegistry.class.getDeclaredField("activeSubstitutions");

map.setAccessible(true);

((BiMap) map.get(registry)).put(registryName, id);

 

field.setAccessible(true);

int modifiers = modifiersField.getInt(field);

modifiers &= ~Modifier.FINAL;

modifiersField.setInt(field, modifiers);

field.set(null, newBlock);

 

Field itemblock = ItemBlock.class.getDeclaredFields()[0];

itemblock.setAccessible(true);

modifiers = modifiersField.getInt(itemblock);

modifiers &= ~Modifier.FINAL;

modifiersField.setInt(itemblock, modifiers);

itemblock.set(item, newBlock);

 

System.out.println("Check field: " + field.get(null).getClass());

System.out.println("Check registry: " + Block.blockRegistry.getObjectById(id).getClass());

System.out.println("Check item: " + ((ItemBlock) Item.getItemFromBlock(newBlock)));

}

}

}

}

catch (Exception e)

{

e.printStackTrace();

return false;

}

return true;

}

 

 

Original 1.7.2 post/solution: http://www.minecraftforge.net/forum/index.php/topic,16692.msg84890.html#msg84890

[Awesome_Spider]

Don't use ASM unless you absolutely have to. If another mod is installed that changes the same class as your mod, guess what happens? Yep, you guessed it, Minecraft crashes.

[Zetal]

I'm okay with that. Mine aren't really meant to work with other mods, but regardless if you have any suggestions for avoiding ASM in this case without reducing the gameplay value of the end-result then I'm all ears. Alternatives would be great, especially since ASM is being such a butt. But right now it's the best way to get the best results that I know of.

[Failender]

Actually I am not sure if this works so its just an idea.

Use livingupdate event. Check if the Player is walking against a log, if He des change his Position to a Position that is higher.

Maybe take a look How ladders are working you could find an idea there

[Zetal]

That would probably work for the logs but without a solution for the leaves I would need to pursue an ASM solution regardless. If I'm going to have to get ASM working no matter what then I may as well use it for both, right? Disabling leaf collision just for specific players... I can't think of a way to do that without touching the core code.

[Awesome_Spider]

Something just came to me! TerraFermaCraft has a similar setup to what you are saying. They have it to where you can go through leaves. But I think they have their own types of leaves... And I don't know if the mod is open source...

[Awesome_Spider]

Yep it is. Poke around in here and look through their leafy code (bad pun):

https://github.com/Deadrik/TFCraft

[Zetal]

After some poking around in general, I found the "addSubstitutionAlias"  method, which seems like it might do what I want?

 

Anyways, I set that up real quick and... well, it sorta... worked..? I replaced all of the logs. It's just... I apparently replaced them with nothing? All of the trees spawned without any logs whatsoever. And trying to place the logs  using creative places... nothing.

 

[Zetal]

Went ahead and updated to the most recent version of Forge after seeing some posts about substitution alias not being complete in older versions, but it still does the same thing.

 

It doesn't replace logs with my block, only destroys logs completely.

[jabelar]

I think it is possible to replace the blocks as the chunk is initially populated with the PopulateChunkEvent. At leas I know you can do it with the main blocks in the world and don't see why it wouldn't work for the trees.

 

I wrote a tutorial on it. Check out the section about replacing blocks on this page: http://jabelarminecraft.blogspot.com/p/minecraft-forge-172-modding-quick-tips.html

[Zetal]

Decided to use your PopulateChunkEvent but for some reason it left some trees randomly un-changed. I changed your code from 'Pre' to 'Post' and that fixed it.

 

Thanks!

 

If anyone knows why the substituteAlias thing didn't work though, I'm interested in that regardless just out of curiosity at this point.