Looking for a starting point. The basic idea is when a liquid is displaced by any block and then that block is mined, the space is filled with the liquid displaced rather than air. How could this be done and what are the limitations of the proposition?

 

Example: digging dirt out of an area marked as a swamp fills that space with water.

Edited August 1, 20178 yr by Stroam

You're unlikely to accomplish this. You would need to store every block position when a block is placed and the location is water, then check that list every time a block is broken, storing the data in per-world storage.  It won't be easy. 

Could it be simplified by having biome specific rules such as swamp level 72 to 65 all air turns to water, Ocean level 63 and lower all turns to water, Etc.

Yes you can use the biome in question, using the block broke event (BlockEvent.BreakEvent) using the world you should be able to get the Biome from the block pos  worldObj.getBiomeForCoordsBody(blockPosHere) you can then do what logic you need to confirm that the block was indeed broken in your desired biome (I'd use the getBiomeName() and match if it contains "swamp" may have to .toLowerCase() just as a precaution on the returned biome name)

from there I recommend using the height of sea level from the world object (worldObj.getSeaLevel()) for your "this is the upper depth of water spawning" then just subtract from that for your lower range worldObj.getSeaLevel() - 17.

I'd also probably recommend having the block (Dirt/Grass, gravel?, sand? better way would be to check if the broken blocks material is the material type you're interested in, this would make it work with other modded blocks (as long as they use the same vanilla material)) check around for any nearby blocks of water so they can simulate "saturation" because breaking a lone block of dirt sitting on a long empty stone layer and having it spew out water would be weird.

However Draco's Suggestion would allow you to set "Areas" or "Zones" that are already saturated with water and potentially allow you to keep things of where player places water with bucket, fills with dirt, breaks again water still there. But as he's already mentioned, won't be easy.

Maybe

OnBlockBreakEvent

if( isInBiomeList(biome) )

{

       double percentWater = sampleArea(blockpos);

       if( percentWater > biome.SATURATION)

       {

            setBlockPos(Water); 

       }

}

 

It can vary based on the water level in the biome without the biome telling it and works unless the player fills in most the water before removing any of the blocks.