[1.8] Mine only a certain depth

[cabelhigh]

Hi all,

 

I'm trying to create a unique shovel that will only mine the first two or three layers of the ground before being unable to go any further. Ideally, this would mean the first two/three levels of both the tallest mountain and the lowest valley. Is this possible?

 

Thanks!

[Ernio]

Not really in means of simple "do this" coding. Something like this would certainly require you to store "highest generated Y coord on this X/Z".

 

If you want to go this way you will need to store mapping of X/Z to Y and when block is mined at some coord - add mapping of its X/Z with value of highest Y block.

Data would be stored in WorldSaveData. To make map as little as possible you can add mapping only when digged block is actually top-block (the highest in X/Z).

 

Other way to do it would be a PURE computation, which would be quite slow (compared to previous way)

When world is generated its seed is set and stays that way. You THEORETICALLY could actually regenerate a chunk in which you dig and check highest block in X/Z pos which then you can compare to one actually mined.

Obviously - you do not want to regenerate chunk, but rather simulate it using world's seed, just to see top block in given x/z.

Much math and byte manipulations if you actually want to do it well (and not slow).

 

Hope it helps in any way.

 

Just an opinion - 2nd way is actually NOT bad (for me). I personally don't like storing stuff, unless its being hashed (which is fast in future usage). Doing real time computation is not that bad if used only during harvest event and when written well.

[cabelhigh]

Awesome, thanks!

 

I had a revelation a few minutes after I posted this that if I made a impossible-to-mine block that was always a few levels under the surface and populated it with WorldGen, that might be easier. But if that doesn't work, thanks for your solution.

[jabelar]

There is actually a heightValue (the method for retrieving it has different names in different versions of Forge, but something like World#getHeightValue() method) for each X, Z position.

 

So my suggestion is this:

1) Create an empty map to hold the original height values according to the world X, Z position.

2) Handle one of the related events, probably the PlayerInteractEvent, or maybe BlockEvent.BreakEvent or the BreakSpeed event as that might be able to cancel the breaking as well.

2) If you're trying to dig with your tool, check if there is already a heighValue in the map you created in Step #1. If yes, then cancel any digging more than 3 blocks down or whatever. If no, then add the height value to the map and allow digging (since this means it is first time you dug in this location).

 

I think that would work. The one thing I'm not certain about is whether trees are included in the height value. I think they are not, but not sure. If they are included in the height value then what you would do is same steps but you would check for leaves and logs downwards from the height value until you hit ground and then put that in your map as the top block.

[Ernio]

Just a wild idea:

We've been talking about X/Z->Y maps and "computation" methods. I think it's worth to mention:

 

I honestly have no clue (never used) about this event but: ChunkDataEvent

As jabelar suggested - you could grab highest point once and save it directly to chunk, that is merely 256 (16x16) short values or if you try hard - you can fit that into one byte ("unsigned").

 

Basically - store 256 byte values with keys "x,z" and one boolean that will tel if this chunk has been ever loaded before (so if not - generate values).

chunkData.setByte("15,9", (byte) -60) // obviously -60 is y=68

 

Then chunk would nicely save its highest points and then you use Load/Save events to get that data in/out of memory.

That way you could make everything very clean and make sure data is nicely saved and removed from memory on chunk unload).

[jabelar]

Just a wild idea:

We've been talking about X/Z->Y maps and "computation" methods. I think it's worth to mention:

 

I honestly have no clue (never used) about this event but: ChunkDataEvent

As jabelar suggested - you could grab highest point once and save it directly to chunk, that is merely 256 (16x16) short values or if you try hard - you can fit that into one byte ("unsigned").

 

Basically - store 256 byte values with keys "x,z" and one boolean that will tel if this chunk has been ever loaded before (so if not - generate values).

chunkData.setByte("15,9", (byte) -60) // obviously -60 is y=68

 

Then chunk would nicely save its highest points and then you use Load/Save events to get that data in/out of memory.

That way you could make everything very clean and make sure data is nicely saved and removed from memory on chunk unload).

 

Yeah, I was thinking that maybe you could just save all height values. It still seems a bit wasteful though since you only really care about spots where you dig. But like you said, it isn't really that much data for a modern computer to record all original height values when chunk is generated.