2-dimensional-toroidal.md

2-dimensional toroidal grid example

In this example we will see how to use the wfc4j library to generate a 2D toroidal pattern with programmatically constructed tiles. Each tile will be the combination of two components.

• First component:

LR__	LB__	LT__	RB__	RT__	BT__

• Second component:

__LR	__LB	__LT	__RB	__RT	__BT

And therefore the adjacency of the tiles will be based on how the two components of each tile fit together with the components of the adjacent tiles. In our example this is computed like this:

import java.util.HashSet;
import dev.irzinfante.wfc4j.enums.Side2D;
import dev.irzinfante.wfc4j.model.Tile;
import dev.irzinfante.wfc4j.model.TileMap2D;

final String LR = "LR", LB = "LB", LT = "LT", RB = "RB", RT = "RT",   BT = "BT";
final var components = new String[] {LR, LB, LT, RB, RT, BT};

var tileSet = new HashSet<Tile<String>>();
for(var first : components) {
	for(var second : components) {
		tileSet.add(new Tile<>(first + second));
	}
}

var tileMap = new TileMap2D<>(tileSet);

for(var tile : tileSet) {
	var tileFirstLeft = tile.getValue().substring(0, 2).contains("L");
	var tileSecondLeft = tile.getValue().substring(2, 4).contains("L");
	var leftAdjacents = new HashSet<Tile<String>>();
	
	var tileFirstRight = tile.getValue().substring(0, 2).contains("R");
	var tileSecondRight = tile.getValue().substring(2, 4).contains("R");
	var rightAdjacents = new HashSet<Tile<String>>();
	
	var tileFirstBottom = tile.getValue().substring(0, 2).contains("B");
	var tileSecondBottom = tile.getValue().substring(2, 4).contains("B");
	var bottomAdjacents = new HashSet<Tile<String>>();
	
	var tileFirstTop = tile.getValue().substring(0, 2).contains("T");
	var tileSecondTop = tile.getValue().substring(2, 4).contains("T");
	var topAdjacents = new HashSet<Tile<String>>();
	
	for(var adjacent : tileSet) {
		var adjacentFirstLeft = adjacent.getValue().substring(0, 2).contains("L");
		var adjacentSecondLeft = adjacent.getValue().substring(2, 4).contains("L");
		if(	(tileFirstRight && adjacentFirstLeft && tileSecondRight && adjacentSecondLeft) ||
			(tileFirstRight && adjacentFirstLeft && !tileSecondRight && !adjacentSecondLeft) ||
			(!tileFirstRight && !adjacentFirstLeft && tileSecondRight && adjacentSecondLeft) ||
			(!tileFirstRight && !adjacentFirstLeft && !tileSecondRight && !adjacentSecondLeft)
		) {
			rightAdjacents.add(adjacent);
		}
		
		var adjacentFirstRight = adjacent.getValue().substring(0, 2).contains("R");
		var adjacentSecondRight = adjacent.getValue().substring(2, 4).contains("R");
		if(	(tileFirstLeft && adjacentFirstRight && tileSecondLeft && adjacentSecondRight) ||
			(tileFirstLeft && adjacentFirstRight && !tileSecondLeft && !adjacentSecondRight) ||
			(!tileFirstLeft && !adjacentFirstRight && tileSecondLeft && adjacentSecondRight) ||
			(!tileFirstLeft && !adjacentFirstRight && !tileSecondLeft && !adjacentSecondRight)
		) {
			leftAdjacents.add(adjacent);
		}
		
		var adjacentFirstTop = adjacent.getValue().substring(0, 2).contains("T");
		var adjacentSecondTop = adjacent.getValue().substring(2, 4).contains("T");
		if(	(tileFirstBottom && adjacentFirstTop && tileSecondBottom && adjacentSecondTop) ||
			(tileFirstBottom && adjacentFirstTop && !tileSecondBottom && !adjacentSecondTop) ||
			(!tileFirstBottom && !adjacentFirstTop && tileSecondBottom && adjacentSecondTop) ||
			(!tileFirstBottom && !adjacentFirstTop && !tileSecondBottom && !adjacentSecondTop)
		) {
			bottomAdjacents.add(adjacent);
		}
		
		var adjacentFirstBottom = adjacent.getValue().substring(0, 2).contains("B");
		var adjacentSecondBottom = adjacent.getValue().substring(2, 4).contains("B");
		if(	(tileFirstTop && adjacentFirstBottom && tileSecondTop && adjacentSecondBottom) ||
			(tileFirstTop && adjacentFirstBottom && !tileSecondTop && !adjacentSecondBottom) ||
			(!tileFirstTop && !adjacentFirstBottom && tileSecondTop && adjacentSecondBottom) ||
			(!tileFirstTop && !adjacentFirstBottom && !tileSecondTop && !adjacentSecondBottom)
		) {
			topAdjacents.add(adjacent);
		}
	}
	
	tileMap.setAdjacents(tile, Side2D.Left, leftAdjacents);
	tileMap.setAdjacents(tile, Side2D.Right, rightAdjacents);
	tileMap.setAdjacents(tile, Side2D.Bottom, bottomAdjacents);
	tileMap.setAdjacents(tile, Side2D.Top, topAdjacents);
}

Please, take your time on understanding the code above.

Now we can instantiate the API class with an 6 by 6 grid:

import dev.irzinfante.wfc4j.api.ToroidalWFC2D;

int gridSizeX = 6, gridSizeY = 6;

Finally we will run the example:

var WFC = new ToroidalWFC2D<String>(tileMap, gridSizeX, gridSizeY);
WFC.run();