Check if block is player placed [SOLVED]

[Atijaf]

I was wondering if there would be a way to check if a player placed a block, efficiently.

 

Not an event that is called when a player places a block, but a variable within each block that can be set to true when a player places it down.

[Failender]

Use  onBlockPlacedBy(World worldIn, BlockPos pos, IBlockState state, EntityLivingBase placer, ItemStack stack) {} and check if placer is an instace of EntityPlayer

[Ernio]

Not an event that is called when a player places a block, but a variable within each block that can be set to true when a player places it down.

Use  onBlockPlacedBy(World worldIn, BlockPos pos, IBlockState state, EntityLivingBase placer, ItemStack stack) {} and check if placer is an instace of EntityPlayer

 

Read again.

 

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There is no "easy" way to do this. You either need to create placing storage or block replacements.

 

1. Storage:

Create smart BlockPos storage that when performing event you want (e.g BreakEvent) will be checked if given block's position is in storage (placed by player). Now problem is - it will be tricky to track every change and may provide false data as some point (you know - you need to track every damn change). It's also not very efficient, best way would be to hash BlockPos and put it in hashMap for fast access. Only way I see it and has to be done smart.

To save your "storage" you would need to implement WorldSaveData.

 

2. Block Replacement:

For every block you want to track you need to create replacement copy.

Since not-placed-by-player are placed by world you can hook into events that generate world and instead of placing vanilla ones, place yours.

YourStone = created by world (replaced via generation event)

Stone (vanilla) = placed by player, acts as normal stone.

Now you know that Stone was placed, and only stone that was NOT placed it the one you made world generate instead of normal one.

 

Both ways require some work and are not always "cool".

[Failender]

Well. You use that method and set your own variable to true? Of course it only works for custom blocks and you have to use nbt (except of if you are using a hashmap or sth full of booleans)

[Ernio]

Block doesn't have NBT, unless it's TileEntity. As to "boolean" - you can use metadata, but be warned that it is used by minecraft internals and won't work for vanilla - for your own block - sure, because you will read meta, for vanilla it's alredy used to define blocks.

[Atijaf]

There is no "easy" way to do this. You either need to create placing storage or block replacements.

 

1. Storage:

Create smart BlockPos storage that when performing event you want (e.g BreakEvent) will be checked if given block's position is in storage (placed by player). Now problem is - it will be tricky to track every change and may provide false data as some point (you know - you need to track every damn change). It's also not very efficient, best way would be to hash BlockPos and put it in hashMap for fast access. Only way I see it and has to be done smart.

To save your "storage" you would need to implement WorldSaveData.

 

I will probably give this a go.  Is WorldSaveData the same in 1.8?  I'm having troubles with implementing it.

Thanks:)

 

Edit: I extended WorldSavedData and am overriding readFromNBT and writeToNBT

[Ernio]

Have look at this:

https://github.com/Questology/Questology/blob/master/src/main/java/demonmodders/questology/QuestologyWorldData.java

 

Something that I personally never used, but read/heard that some find solutions there (it looks good to me).

[Atijaf]

Have look at this:

https://github.com/Questology/Questology/blob/master/src/main/java/demonmodders/questology/QuestologyWorldData.java

 

Something that I personally never used, but read/heard that some find solutions there (it looks good to me).

 

I had a look at it and am understanding what it is doing.  However, I am unsure how I would check the instance of that class if it holds the BlockPos of the block I'm breaking.  Would I use a hashMap for storing them?  Also, How would I go about using the variable BlockPos in a hashMap?

 

Thanks a bunch!

[diesieben07]

Yes, you could use a HashMap, if you want to e.g. map positions to player names/UUIDs. Or a HashSet if you merely want to keep track of which positions are placed by a player.

Not sure what you mean by this:

Also, How would I go about using the variable BlockPos in a hashMap?

[tiffit]

he means how would he put a blockpos in the map

[Atijaf]

I am fairly new at hashMaps.  I'll see what I can do!

[diesieben07]

You should read up on that then. There are plenty of Java tutorials available.

[Atijaf]

Thanks everyone for the help and input!

[Atijaf]

I understand that this post is old, but I have completed implementing a block storage that stores the location, and the block's id/meta.

 

I have a List of dimensions, -1 through 14. (-1 is actually 15), and any other dimensions can go up to 14.

 

Inside the list of dimensions, holds a sorted ArrayList of my "ChunkPos" objects. (These objects contain dimension Id, X and Z position.  48 bits... 4 bits dimension, 22 bits X, 22 bits Z) 

 

This chunk also holds a HashMap of my "ChunkBlockPos" objects.  (These objects contain x -4 bits, y -8 bits, and z-4 bits coords.  Along with the block Id -12 bits and meta -4 bits)

 

Each chunk is 48 bits, and each block within is 32 bits.  That is also calculated without java's overhead for my classes and whatnot...  Unfortunately, I had to include the block's id and meta, in case if the player places a sapling and it grows, the location of the sapling is now wood and that wood was not placed by a player.

 

 

And now for getting the information.  When a player places a block, it goes into the dimension list, it then does a binary search for the chunk, and if not found, creates a new chunk, instantiates the hashmap within, and instantiates a "ChunkBlockPos", inserts that into the hashmap, and adds the hashmap to the dimension list.

 

In other words, if there are 100,000 chunks stored within the dimension list, it can find the correct chunk within 17 searches doing a binary search.  Woot!

 

AND NO, I haven't been working on this for a year.  I was just looking through my questions and found this one.  I figured I'd update it and say thanks to all of y'all!  Thanks!

[Atijaf]

The only loop hole that I can think of now is if the block is pushed somewhere.  i.e. a piston.

 

Are there any piston related events?

 

I can fix if sand is placed and then it falls (I'll just put the lowest location)

[Draco18s]

You are going to have a lot of problems making this work, sadly.