[1.11.2] swapping blocks in a chunk issue

[salvestrom]

The spoiler code below is something I found in another thread (the poster said it was diesenben's). i added the height check. the goal is to replace all the stone below half the terrain height with something else. This all works, with one annoying issue: the returned y location from getHeightValue is including leaves and trees. i was expecting/would like the height value to be the "ground" so to speak. All paths lead to Rome, that I've found, i.e calling event.getWorld().getHeight(stuff) ultimately calls getHeightValue in the chunk class.

Spoiler

	@SubscribeEvent
	public void blockSwap(PopulateChunkEvent.Pre pce)
	{
	
	    Chunk chunk = pce.getWorld().getChunkFromChunkCoords(pce.getChunkX(), pce.getChunkZ());
	    Block tobeReplaced = Blocks.STONE;
	    
	    for (ExtendedBlockStorage storage : chunk.getBlockStorageArray())
	    	if(storage != null)
	    	{
	    		{
	                for (int x = 0; x < 16; ++x) 
	                {
	                    for (int y = 0; y < 16; ++y) 
	                    {
	                        for (int z = 0; z < 16; ++z) 
	                        {
	                    	    int a = chunk.getHeightValue(x, z) / 2;
	                    	    //pce.getWorld().getHeight(pce.getChunkX()*16 + x, pce.getChunkZ()*16 + z)/2;

	                            if (storage.get(x, y, z) == tobeReplaced.getDefaultState()
	                            		&& storage.getYLocation() + y < a) 
	                            {
	                                storage.set(x, y, z, Blocks.SANDSTONE.getDefaultState());
	                            }
	                        }
	                    }
	                }
	            }
	    	}

	    chunk.setModified(true); // this is important as it marks it to be saved
	}

 

 

[Animefan8888]

Just create a method yourself that takes in a x and z and iterate from y = 0 to the height you want.

[Draco18s]

Actually, iterate from world.getSeaLevel (world.provider.getSeaHeight? Something along those lines) upwards.  There's no need to check from 0 to 60 in the overworld. You know those are going to be stone, air, or water.  And look for areas with sunlight > 5 or so.  And look for the last stone, sand, gravel, or dirt block (looking for grass won't help, because it'll just iterate up the trunk of a tree) before finding sunlight.  Alternatively you could use the value returned by getHeightValue and iterate downwards until you find sand/grass/dirt/stone/water/lava.

 

That'll get you the best result, I think.

 

You could also check all adjacent blocks to the column being searched and if any meet the criteria for "what is ground" and average the result.  Note: vertical cave entrances will give slightly wonky values because their "surface" point will be below the surrounding area, but this may not be a big deal.

[salvestrom]

	public int findGroundHeight(int x, int y, int z, Chunk chunk, ExtendedBlockStorage storage, Block toRemove, Block toPlace)
	{
		int cy = chunk.getHeightValue(x, z);
		
		while(chunk.getWorld().getBlockState(new BlockPos(chunk.xPosition * 16 + x, cy, chunk.zPosition * 16 + z))
				!= toRemove.getDefaultState())
		{
			cy = cy - 1;
		}
			
		return cy;
	}

 

i'm using the above atm, calling the method from the op code at the "int a = " line. although, as draco noted, exposed tunnels and ravines throw things off, it works to ignore trees. however, the terrain eventually stops loading and is alittle laggy even before that. i appreciate that what i'm doing is going to slow things down alot, so i'm more interested in whats causing the terrain to just give up. even after reloading the same region will lock up.

[Draco18s]

So, a couple things.

chunk.getWorld().getBlockState(...)

This can be better.

Option 1: store the result of chunk.getWorld() to a local variable and use world.getBlockState()

Option 2: skip the world object and use chunk.getBlockState()

new BlockPos(...)

Don't do this. BlockPos objects are (sort of) mutable.  Use a local variable and pos = pos.down() instead.

[salvestrom]

Spoiler

	public int findGroundHeight(int x, int y, int z, Chunk chunk, ExtendedBlockStorage storage, Block toRemove, Block toPlace)
	{
		int cy = chunk.getHeightValue(x, z);
		
		BlockPos pos = new BlockPos(chunk.xPosition * 16 + x, cy, chunk.zPosition * 16 + z);
		
		while(chunk.getBlockState(pos) != toRemove.getDefaultState())
		{
			pos = pos.down();
		}
			
		return pos.getY();
	}

 

The method is now as above. This helped a little with the load time, but did not resolve the locking up. i disabled the code and reloaded the world to determine what is in the region. an extreme hills biome. a large, tall one. but i figure if the game is checking the entirety of every loading chunk its not going to matter what that chunk contains. i keep wondering if some special circumstance is causing the while() statement to get stuck in an infinite loop. the method in the op already has a null check on the ExtendedBlockStorage, so it's not that. hmm. perhaps i shall try throwing in a break if y < 0...

[salvestrom]

Adding pos.getY() > 0 to the while statement allowed the extreme hills to load, and after 5 min roaming have yet to find another area that locked the game up. the only thing i can think of, bizarre as it sounds, is that some column in a chunk contained no stone, allowing the while loop to go all the way down to bedrock and on into the void.