[1.8.9] Worldgen with custom tree

[blahblahbal]

I know I have a running thread that isn't solved yet, but because it isn't solved (and I've exhausted my thought processes for that particular area), I thought I'd move over to a different part of my mod. One that involves my custom biome, the Tropics. Anyway, when trying to make a custom tree (a palm tree), I get an error on worldgen with a seed I know spawns you in the new custom biome:

https://pastebin.com/1rC4xggP

 

This is the code for WorldGenDifferentPalmTree (line 190 is the line in generate() that has the leafPosMod3 array in it):

 

package main.java.blahblahbal.blahmod.world;

import java.util.Random;

import main.java.blahblahbal.blahmod.blocks.BlockPalmLeaves;
import main.java.blahblahbal.blahmod.blocks.ModBlocks;
import net.minecraft.block.state.IBlockState;
import net.minecraft.util.BlockPos;
import net.minecraft.world.World;
import net.minecraft.world.gen.feature.WorldGenAbstractTree;

public class WorldGenDifferentPalmTree extends WorldGenAbstractTree
{
	private static final IBlockState log = ModBlocks.palmLog.getDefaultState();
    private static final IBlockState leaves = ModBlocks.palmLeaves.getDefaultState().withProperty(BlockPalmLeaves.CHECK_DECAY, Boolean.valueOf(false)).withProperty(BlockPalmLeaves.DECAYABLE, Boolean.valueOf(false));
    private static final IBlockState coco = ModBlocks.coconut.getDefaultState();
    private int[][] logPosMod1 = new int[][]
    {
    	{0, 0, 0}, {0, 1, 0}, {0, 2, 0}, {0, 3, 0},
    	{0, 4, -1}, {0, 5, -1}, {0, 6, -2}, {0, 7, -3}
    };
    private int[][] logPosMod2 = new int[][]
    {
    	{0, 0, 0}, {0, 1, 0}, {0, 2, 0}, {0, 3, 0},
    	{0, 4, 1}, {0, 5, 1}, {0, 6, 2}, {0, 7, 3}
    };
    private int[][] logPosMod3 = new int[][]
    {
    	{0, 0, 0}, {0, 1, 0}, {0, 2, 0}, {0, 3, 0},
    	{-1, 4, 0}, {-1, 5, 0}, {-2, 6, 0}, {-3, 7, 0}
	};
	private int[][] logPosMod4 = new int[][]
    {
    	{0, 0, 0}, {0, 1, 0}, {0, 2, 0}, {0, 3, 0},
    	{1, 4, 0}, {1, 5, 0}, {2, 6, 0}, {3, 7, 0}
	};
    private int[][] leafPosMod1 = new int[][]
    {
    	{0, 8, -3}, {0, 8, -2}, {0, 8, -1},
     	{1, 8, -3}, {1, 8, -2}, {1, 8, -1},
     	{-1, 8, -3}, {-1, 8, -2}, {-1, 8, -1},
     	{0, 8, -4}, {0, 8, -5},
     	{1, 8, -4}, {1, 8, -5},
     	{-1, 8, -4}, {-1, 8, -5},
     	{2, 8, -2}, {2, 8, -3}, {2, 8, -4},
     	{-2, 8, -2}, {-2, 8, -3}, {-2, 8, -4},
     	{3, 7, -2}, {3, 7, -3}, {3, 7, -4},
     	{-3, 7, -2}, {-3, 7, -3}, {-3, 7, -4},
     	{0, 7, 0}, {1, 7, 0}, {-1, 7, 0},
     	{0, 7, -6}, {1, 7, -6}, {-1, 7, -6},
     	{0, 7, 1},
     	{0, 7, -7},
     	{-4, 7, -3},
     	{4, 7, -3}
    };
    private int[][] leafPosMod2 = new int[][]
    {
    	{-1, 8, 1}, {0, 8, 1}, {1, 8, 1},
    	{-1, 8, 2}, {0, 8, 2}, {1, 8, 2},
    	{-1, 8, 3}, {0, 8, 3}, {1, 8, 3},
    	{0, 8, 0}, {0, 8, -1},
    	{1, 8, 0}, {1, 8, -1},
    	{-1, 8, 0}, {-1, 8, -1},
    	{2, 8, 2}, {2, 8, 1}, {2, 8, 0},
    	{-2, 8, 2}, {-2, 8, 1}, {-2, 8, 0},
    	{3, 7, 2}, {3, 7, 1}, {3, 7, 0},
    	{-3, 7, 2}, {-3, 7, 1}, {-3, 7, 0},
    	{0, 7, 4}, {1, 7, 4}, {-1, 7, 4},
    	{0, 7, -2}, {1, 7, -2}, {-1, 7, -2},
    	{0, 7, 5},
    	{0, 7, -1},
    	{-4, 7, 1},
    	{4, 7, 1}
    };
    private int[][] leafPosMod3 = new int[][]
    {
    	{1, 8, -1}, {2, 8, -1}, {3, 8, -1},
    	{1, 8, 0}, {2, 8, 0}, {3, 8, 0},
    	{1, 8, 1}, {2, 8, 1}, {3, 8, 1},
    	{2, 8, -2}, {2, 8, -3},
    	{3, 8, -2}, {3, 8, -3},
    	{1, 8, -2}, {1, 8, -3},
    	{4, 8, 0}, {4, 8, -1}, {4, 8, -2},
    	{0, 8, 0}, {0, 8, -1}, {0, 8, -2},
    	{5, 7, 0}, {5, 7, -1}, {5, 7, -2},
    	{-1, 7, 0}, {-1, 7, -1}, {-1, 7, -2},
    	{2, 7, 2}, {3, 7, 2}, {1, 7, 2},
    	{2, 7, -4}, {3, 7, -4}, {1, 7, -4},
    	{2, 7, 3},
    	{2, 7, -3},
    	{-2, 7, -1},
    	{6, 7, -1}
    };
    private int[][] leafPosMod4 = new int[][]
    {
    	{-3, 8, -1}, {-2, 8, -1}, {-1, 8, -1},
    	{-3, 8, 0}, {-2, 8, 0}, {-1, 8, 0},
    	{-3, 8, 1}, {-2, 8, 1}, {-1, 8, 1},
    	{-2, 8, -2}, {-2, 8, -3},
    	{-1, 8, -2}, {-1, 8, -3},
    	{-3, 8, -2}, {-3, 8, -3},
    	{0, 8, 0}, {0, 8, -1}, {0, 8, -2},
    	{-4, 8, 0}, {-4, 8, -1}, {-4, 8, -2},
    	{1, 7, 0}, {1, 7, -1}, {1, 7, -2},
    	{-5, 7, 0}, {-5, 7, -1}, {-5, 7, -2},
    	{-2, 7, 2}, {-1, 7, 2}, {-3, 7, 2},
    	{-2, 7, -4}, {-1, 7, -4}, {-3, 7, -4},
    	{-2, 7, 3},
    	{-2, 7, -3},
    	{-6, 7, -1},
    	{2, 7, -1}
    };
    private int[][] cocoPos1 = new int[][]
    {
    	{0, 7, -3}, {0, 7, -1}, {1, 7, -2}, {-1, 7, -2}
    };
    private int[][] cocoPos2 = new int[][]
    {
    	{0, 7, 1}, {0, 7, 3}, {1, 7, 2}, {-1, 7, 2}
    };
    private int[][] cocoPos3 = new int[][]
    {
    	{-2, 7, -1}, {-2, 7, 1}, {-1, 7, 0}, {-3, 7, 0}
    };
    private int[][] cocoPos4 = new int[][]
    {
    	{2, 7, -1}, {2, 7, 1}, {3, 7, 0}, {1, 7, 0}
    };
    public WorldGenDifferentPalmTree(boolean f)
    {
    	super(false);
    }
	public WorldGenDifferentPalmTree(World worldIn, Random rand, BlockPos pos)
	{
		super(true);
		generate(worldIn, rand, pos);
	}

	public boolean generate(World arg0, Random arg1, BlockPos arg2)
	{
		if (arg0.getBlockState(arg2.down()).getBlock() != ModBlocks.blackSand) return false;
		int rn = arg1.nextInt(4);
		if (rn == 0)
		{
			buildLayer(arg0, arg2, logPosMod1, log);
			buildLayer(arg0, arg2, leafPosMod1, leaves);
			buildLayer(arg0, arg2, cocoPos1, coco);
		}
		else if (rn == 1)
		{
			buildLayer(arg0, arg2, logPosMod2, log);
			buildLayer(arg0, arg2, leafPosMod2, leaves);
			buildLayer(arg0, arg2, cocoPos2, coco);
		}
		else if (rn == 2)
		{
			buildLayer(arg0, arg2, logPosMod3, log);
			buildLayer(arg0, arg2, leafPosMod3, leaves);
			buildLayer(arg0, arg2, cocoPos3, coco);
		}
		else if (rn == 3)
		{
			buildLayer(arg0, arg2, logPosMod4, log);
			buildLayer(arg0, arg2, leafPosMod4, leaves);
			buildLayer(arg0, arg2, cocoPos4, coco);
		}
		/*buildLayer(arg0, arg2, logPosMod1, log);
		buildLayer(arg0, arg2, leafPosMod1, leaves);
		buildLayer(arg0, arg2, cocoPos1, coco);*/
		return true;
	}
	private void buildLayer(World world, BlockPos frontLeftCorner, int[][] blockPositions, IBlockState toPlace)
	{
		// iterate through the entire int[][]
		for(int[] coord : blockPositions)
		{
			placeBlock(world, frontLeftCorner, coord[0], coord[1], coord[2], toPlace);
		}
	}
	/** Helper Method **/
	private void placeBlock(World world, BlockPos frontLeftCorner, int[] offsets, IBlockState toPlace)
	{
		placeBlock(world, frontLeftCorner, offsets[0], offsets[1], offsets[2], toPlace);
	}

	/** Places a block using corner position and offsets **/
	private void placeBlock(World world, BlockPos frontLeftCorner, int offsetX, int offsetY, int offsetZ, IBlockState toPlace)
	{	
		// figure out where that block is relative to the corner
		BlockPos placePos = frontLeftCorner.add(offsetX, offsetY, offsetZ);
		world.setBlockState(placePos, toPlace, 2);
	}
}

 

Side note: I also can't figure out how to force the custom leaves to not decay after a short while. (This is why I've set the leaves' CHECK_DECAY and DECAYABLE to false.

[blahblahbal]

Extra information - If I change the generation to only include one of the four offsets (each of which create a slant of the tree), it generates just fine. I'm not even sure what this would tell me. Especially since the error is 'Already decorating,' which makes no sense to me.

[V0idWa1k3r]

You are most likely trying to generate your tree in a chunk that has not been generated yet, triggering recursion. As far as I remember the 'already decorating' exception is thrown to prevent that. How and where are you calling your generate method?

[blahblahbal]

The problem with that theory is that when I generate it with just one of the four 'slants' it works. The issue arises when I try to randomize the slant to one of four directions.

[V0idWa1k3r]

When you are generating one of four 'slants' that slant might be generating in an existing chunk. As you add more your placeBlock method attempts to place a block in a chunk that has not been generated yet thus causing an issue. It is visible if you inspect the stacktrace :

Spoiler

1. at net.minecraft.world.biome.BiomeDecorator.func_180292_a(BiomeDecorator.java:71)
2.     at net.minecraft.world.biome.BiomeGenBase.func_180624_a(BiomeGenBase.java:343)
3.     at net.minecraft.world.gen.ChunkProviderGenerate.func_73153_a(ChunkProviderGenerate.java:453)
4.     at net.minecraft.world.gen.ChunkProviderServer.func_73153_a(ChunkProviderServer.java:261)
5.     at net.minecraft.world.chunk.Chunk.func_76624_a(Chunk.java:1081)
6.     at net.minecraft.world.gen.ChunkProviderServer.originalLoadChunk(ChunkProviderServer.java:172)
7.     at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:114)
8.     at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:84)
9.     at net.minecraft.world.gen.ChunkProviderServer.func_73154_d(ChunkProviderServer.java:181)
10.     at net.minecraft.world.World.func_72964_e(World.java:287)
11.     at net.minecraft.world.World.func_175726_f(World.java:282)
12.     at net.minecraft.world.World.func_180501_a(World.java:302)
13.     at main.java.blahblahbal.blahmod.world.WorldGenDifferentPalmTree.placeBlock(WorldGenDifferentPalmTree.java:223)

Note how it goes from your placeBlock method to a world, then ChunkProviderServer, then ChunkProviderGenerate, then BiomeGenBase. You are trigerring a new chunk generation.

Edited May 25, 2017 by V0idWa1k3r

[blahblahbal]

So... how would I go about generating this tree then? If it's trying to generate in a chunk that isn't there yet... Is it possible to force a chunk to generate before the tree is generated?

 

EDIT: I realized I forgot to say where I call my generate method. I'm calling it in both the Palm Sapling block code and in the BiomeGenTropics file.

 

For reference, here is the github repo: https://github.com/blahblahbal/Blah-s-Minecraft-Mod/tree/Structure-fix

 

The first is in the block folder, the second is in the world folder.

Edited May 25, 2017 by blahblahbal

[V0idWa1k3r]

Well, I've tried to replicate your issue but even with something as ridiculous as this I couldn't get my game to crash. 

Spoiler

Yes, I've uncommented the lines that randomize leaves positions.
And yes, I've used a world that pretty much spawns you in the biome. 

Granted, I've used a more recent version of forge for 1.8.9...

Anyway, you could try and check if the chunk you are generating in exists, and the chunks that are triggered by your offsets exist before firing any generation. (IChunkProvider::chunkExists). Do not forget that that method takes chunk coordinates as it's arguments, not block coordinates

[blahblahbal]

I just started work on a new biome, and I'm getting the same error. I wonder if updating to 1902 will fix this problem. I'll reply here when I find that out.

[blahblahbal]

Nope, same issue. For reference, here is the code for the new tree:

package blahblahbal.blahmod.world;

import java.util.Random;

import blahblahbal.blahmod.blocks.ModBlocks;
import net.minecraft.block.state.IBlockState;
import net.minecraft.util.BlockPos;
import net.minecraft.world.World;
import net.minecraft.world.gen.feature.WorldGenAbstractTree;

public class WorldGenCedarTree extends WorldGenAbstractTree
{
	private static final IBlockState log = ModBlocks.cedarLog.getDefaultState();
	private static final IBlockState leaf = ModBlocks.cedarLeaves.getDefaultState();
	public WorldGenCedarTree(boolean f)
	{
		super(false);
	}
	public WorldGenCedarTree(World w, Random r, BlockPos bp)
	{
		super(true);
		generate(w, r, bp);
	}
	@Override
	public boolean generate(World worldIn, Random rand, BlockPos position)
	{
		if (position.getY() < 10 || position.getY() > 240) return false;
		int rn = rand.nextInt(5);
		int leafRad = rand.nextInt(5) + 4;
		
		int TOP_POS = position.getY() + rn + 14;
		int distTopBot = (TOP_POS) - (position.getY() + 4);			// distance between the top and the bottom minus 4
		int middleTopBot = (int)(distTopBot / 2);					// the middle
		int TOP_HALF_POS = TOP_POS - middleTopBot;					// the top half position
		int distTopToHalf = TOP_POS - TOP_HALF_POS;					// distance between top and middle
		int middleTopHalf = (int)(distTopToHalf / 2);				// the middle between top and middle
		int TOP_QUARTER_POS = TOP_POS - middleTopHalf;				// the top quarter position
		int distTopToQuarter = TOP_POS - TOP_QUARTER_POS;			// distance between top and quarter
		int middleTopQuarter = (int)(distTopToQuarter / 2);			// the middle between top and quarter
		int TOP_EIGHTH_POS = TOP_POS - middleTopQuarter;			// the top eighth position
		
		for (int x = position.getX(); x <= position.getX() + 1; x++)
		{
			for (int z = position.getZ(); z <= position.getZ() + 1; z++)
			{
				for (int y = position.getY(); y <= position.getY() + rn + 14; y++)
				{
					if (y > position.getY() + 4)
					{
						makeCircle(x, y, z, leafRad, leaf, worldIn);
					}
					else if (y >= TOP_HALF_POS)
					{
						makeCircle(x, y, z, leafRad - 1, leaf, worldIn);
					}
					else if (y >= TOP_QUARTER_POS)
					{
						makeCircle(x, y, z, leafRad - 2, leaf, worldIn);
					}
					else if (y >= TOP_EIGHTH_POS)
					{
						makeCircle(x, y, z, leafRad - 3, leaf, worldIn);
					}
					if (y < position.getY() + rn + 12) this.setBlockAndNotifyAdequately(worldIn, new BlockPos(x, y, z), log);
				}
			}
		}
		return true;
	}
	public void makeCircle(int x, int y, int z, float r, IBlockState state, World world)
	{
		int fx = (int)(x - r); //first x
		int fy = (int)(z - r); //first y
		int lx = (int)(x + r); //last x
		int ly = (int)(z + r); //last y
		for (int i = fx; i < lx + 1; i++)
		{
			for (int j = fy; j < ly + 1; j++)
			{
				if (distance(i, j, x, z) <= r)
				{
					if (state == null) world.setBlockToAir(new BlockPos(i, y, j));
					else this.setBlockAndNotifyAdequately(world, new BlockPos(i, y, j), state);
				}
			}
		}
	}
	public static float distance(float x1, float y1, float x2, float y2)
	{
		final float x_d = x2 - x1;
		final float y_d = y2 - y1;
		return (float)Math.sqrt(x_d * x_d + y_d * y_d);
	}
}

 

It throws the Already decorating exception at the first leaf placement line.

[blahblahbal]

Scratch that last post. I ran a chunkExists check and now it works. Thanks for helping out.

[jeffryfisher]

Advice:

1) Fix indentation. Your code is hard to read.

2) You don't show the call(s) to WorldGenCedarTree(...), so we can't see if the arguments make sense.

3) Take care with pos; be careful to not spread generation into new chunks north and/or west of the one in which your tree starts (see "runaway worldgen").

[blahblahbal]

By indentation do you mean me putting if statements' bodies on the next line in some places and not in others?

 

And it's solved anyway, since I ran a chunkExists check. I also just realized I probably could have used modulus instead of all those math operations above the for loops.

[jeffryfisher]

3 hours ago, blahblahbal said:

By indentation do you mean

Never mind; it was probably just the reinterpretation of tabs in your OP. I'm glad you found a solution.

 

Note to self: Tell my editor to replace tabs with spaces so that other people see what I see if/when I share code.