Check fences to one direction

Hello,

I developing a plugin and i need to make a loop on all fences to check if this fences are a retangle or square.

I need to check to make this valid:


And this invalid:


Basicly, i need to check if the fences only go to front and right, or go to back and left, not to front and both directions.

I tryed this:

Code:

for (int bi = 0; bi < block.size(); ++bi) {
                    BlockFace backface = current.getFace(block[bi]);
                    BlockFace currface = block[bi].getFace(current);
                    if (currface.equals(BlockFace.UP) || currface.equals(BlockFace.DOWN) ||
                            (currface.equals(BlockFace.EAST) && backface.equals(BlockFace.WEST)) ||
                            (currface.equals(BlockFace.NORTH) && backface.equals(BlockFace.SOUTH)) ||
                            (currface.equals(BlockFace.WEST) && backface.equals(BlockFace.EAST)) ||
                            (currface.equals(BlockFace.SOUTH) && backface.equals(BlockFace.NORTH)) ||
                            //curvas
                            (currface.equals(BlockFace.WEST) && backface.equals(BlockFace.NORTH)) ||
                            (currface.equals(BlockFace.EAST) && backface.equals(BlockFace.NORTH)) ||
                            (currface.equals(BlockFace.SOUTH) && backface.equals(BlockFace.EAST)) ||
                            (currface.equals(BlockFace.WEST) && backface.equals(BlockFace.SOUTH))
                            ){
                       ...
                      loop continues...
                      ...
                    } else {
                        seterror("Need to be a square!")
                        break;
                    }
}

But always is valid :/

 

@FabioZumbi12

That logic looks awful, to be honest.

Use a simple state machine, start at one corner, then check if it's the correct direction, or the only valid turn for that direction.

 

Yes, is awlful because i have no ideia on how to do.

The "block" is a "Block[]" with all fences from a other scan from last block to next block.

I know the fences have two faces, the back and front, but how to check if the front block(following direction of loop) isn't a fence and then, check to the +90 degrees to get another block and validade as fence?

 

It's just a bit of logic with some looping that you need.

If you can't figure out how to handle it yourself, you could consider submitting a plugin request instead

Otherwise, maybe take a look at a Wall Follower algorithm, might be a good start

 

1.: Create a while loop. Loop trough all the block in one direction, until it is air or not a fence, always check for fences in the other directions, stop if there are.
2.: Once you got to a corner, turn around, and store somehow the next direction you need to go.
3.: Repeat the first 2 points, until you get back to the original position, if the fence turns too much, or it turns in a wrong direction, then end the cycle.
It's not that hard.

 

But theres a code example to Loop and get the fences only for -> direction and for <- direction?

 

We won't provide code here, and I don't think there would be.