[1.7.10] Hollow Multiblock Structure

[LordMastodonFTW]

Hello, does anyone have any ideas on how I could make a hollow multiblock structure? Meaning that it would have walls on all sides, but no blocks in the middle. Thanks in advance!

[Whov]

when you place a block (from your mod ideally) override onBlockAdded and perform some checks for the near blocks. You must consider where that block might go. Example: railcraft has tanks. When you place any of the blocks it performs a check counting how many blocks there are in x, y and z. If one of them is 1 (1 layer) the other 2 are the height and width of the tank. After that, check if the structure is valid and, if it is, find the center block and set its tile entity (all of the blocks probably have a tile entity I would guess) to store all the data (size, pos, fluid, amount...). You might want to set the metadata of the blocks "part of a multiblock" to some value (maybe different values based on position) for rendering purposes. The trick to make it look cool is, of course, connected textures. Hope this helps!

[LordMastodonFTW]

Yup, it certainly does. Thanks!

[LordMastodonFTW]

However, could you elaborate a bit? Not copy/paste code, but a bit more in depth? Cause I was having a little trouble fully understanding.

[Whov]

It depends on what you want to get. There is no cookbook ready to use because you can have various multiblock structures. Do you have a shape for your multiblock or does it need to change a lot (like irregular shapes, far from cuboids)? Moreover, do you have a particular block that is like a "masterpiece" (like ars magica has that key block for the portals and the altar) or, like railcraft, it's just blocks from your mod that are used specifically for that purpose? Do you want to allow multiple multiblocks of the same type side by side? Besides, is the multiblock formed on some event (right click of a valve like good old XYcraft tanks)?. The key to make it is considering exactly what you want and find common schemes present in each one. Give me a general idea and I'll come up with something. Bye!

PS: please, don't tell me you want a totally irregular one, I made one (the first and only multiblock I ever made), but they are crazy. Basically it would keep looking for adiacent blocks until it found valid ones and then save all the coords. Fun times when it comes to break such a thing..

[LordMastodonFTW]

Nah, I just want a normal hollow 5 x 5 x 5. I do want the activation to be based on a right-click, and I do want different blocks in the multiblock to have different metadata. Again, don't provide me with copy/paste, just basic instruction.

[LordMastodonFTW]

I'm sorry, but b-b-b-b-bump, b-b-b-b-b-b-bump.

[Whov]

Ok. You will need a function that checks if multiblock structure is valid and that eventually makes it setting the metadata values and activating some tile entities maybe. That would be called from onBlockActivated. You will also need a breakMultiblock method that is called when you do something like breaking a block that is part of the structure.

 

For some code to check if multiblock structure is valid you must be either creative or copy from some tutorials on the net. I suggest something like 3 nested for loops from -4 to 0 and check every block: if it's valid (metadata==0 so not already part of multiblock and block==yourBlock) the consider it the bottom left left corner and perform a check (like 3 more nested for loops 0-4 and, if one of the variables is 0 or 4, then you are in a face/edge/corner => must be yourblock and metadata==0, else must be air block). If returns false then just keep on looping. Else found multiblock at coords of the bottom left left corner x,y,z and call a method to set metadata (like 1 for corner, 2 for edge and 3 for face, just base on the variables of the for loops and see if the are the min or the max) and, I suggest, set all the tile entities of the blocks to refer to a master block (like the center bottom one) doing something like coords of bottom left left corner + 2 on x and z and that is the master. Every other tile entity will send every request to that tile.

 

Now make sure that onBlockActivated does that only if metadata==0, else open some kind of gui or whatever sending the request like this: ((MultiBlockTile)world.getTileEntity(x, y, z)).getMasterBlock().doWhateverYouWant(). getMasterBlock gets the tile entity from the same world of the one you clicked but with the saved (also in NBT!!) coordinates.

 

Last but not least in your onBlockDestroyed (might be another name) if your block has metadata>0 than get the tile entity, get the master and from those coords (might be useful to shift x and z back 2 so that you can use the same algorithm of the create method) break the multiblock setting metadata=0 and tileEntity master=null or something. Don't necessarely wipe out all the data from the master, just delete all references to it for the time being. That will allow players to change every other block in the structure (swap blocks for others like tank valve for gauge) and not lose all the honey..I mean data . Of course, if you attach a custom tileEntitySpecialRenderer to your tiles and, based on metadata or something, do some magic rendering that would be the best 

Post again if you have more questions

[LordMastodonFTW]

How do you think I could get the x/y/z for the bottom left block using the x/y/z of the currently placed block?

[Whov]

With the first (3) for loops, the ones from -4 to 0. if block is valid then check assuming it is left bottom corner

[LordMastodonFTW]

But my problem with that is what if it's the top middle or something like that. Then, my for loops would return something completely wrong and the player would have to place the block in the bottom left to get it to work. How would I get it to do the for loops with an x/y/z relative to the bottom left corner rather than an x/y/z relative to the block itself?

[Whov]

for x1, y1, z1 [-4;0] getBlock. if block==... then isMultiBlock(x+x1, y+y1, z+z1);

//if the corner were further then this block wouldn't be in the structure anyway

 

isMultiBlock(x, y, z) {

for x1, y1, z1 [0;4] {block = getBlock(x+x1, y+y1, z+z1);

if (inside&&block!=air||corner&&block!=yours) return false;

}

formMultiBlock(x, y, z);//do the things

return true;

}

[LordMastodonFTW]

What do you mean by [-4; 0]?

[Whov]

for (int i=-4;i<=0;i++) do...

it means in range -4 to 0 included (so -4, -3, -2, -1, 0). Same for [0;4] from 0 to 4 included (by the way, ]0;4[ would mean excluded)

[LordMastodonFTW]

Ah, I see.