Plex-FAWE/worldedit-core/src/main/java/com/boydti/fawe/object/extent/RandomOffsetTransform.java

package com.boydti.fawe.object.extent;

import com.sk89q.worldedit.WorldEditException;
import com.sk89q.worldedit.blocks.BaseBlock;
import com.sk89q.worldedit.world.block.BlockState;
import com.sk89q.worldedit.extent.Extent;
import com.sk89q.worldedit.math.BlockVector2;
import com.sk89q.worldedit.math.BlockVector3;
import com.sk89q.worldedit.math.MutableBlockVector2D;
import com.sk89q.worldedit.world.biome.BaseBiome;
import com.sk89q.worldedit.world.block.BlockStateHolder;

import java.util.SplittableRandom;

public class RandomOffsetTransform extends ResettableExtent {
    private transient SplittableRandom random;
    private transient MutableBlockVector2D mutable = new MutableBlockVector2D();

    private final int dx, dy, dz;

    public RandomOffsetTransform(Extent parent, int dx, int dy, int dz) {
        super(parent);
        this.dx = dx + 1;
        this.dy = dy + 1;
        this.dz = dz + 1;
        this.random = new SplittableRandom();
    }

    @Override
    public boolean setBiome(BlockVector2 pos, BaseBiome biome) {
        int x = pos.getBlockX() + random.nextInt(1 + (dx << 1)) - dx;
        int z = pos.getBlockZ() + random.nextInt(1 + (dz << 1)) - dz;
        return getExtent().setBiome(mutable.setComponents(x, z).toBlockVector2(), biome);
    }

    @Override
    public boolean setBlock(BlockVector3 pos, BlockStateHolder block) throws WorldEditException {
        int x = pos.getBlockX() + random.nextInt(1 + (dx << 1)) - dx;
        int y = pos.getBlockY() + random.nextInt(1 + (dy << 1)) - dy;
        int z = pos.getBlockZ() + random.nextInt(1 + (dz << 1)) - dz;
        return getExtent().setBlock(x, y, z, block);
    }

    @Override
    public boolean setBlock(int x, int y, int z, BlockStateHolder block) throws WorldEditException {
        x = x + random.nextInt(1 + (dx << 1)) - dx;
        y = y + random.nextInt(1 + (dy << 1)) - dy;
        z = z + random.nextInt(1 + (dz << 1)) - dz;
        return getExtent().setBlock(x, y, z, block);
    }

    @Override
    public ResettableExtent setExtent(Extent extent) {
        random = new SplittableRandom();
        mutable = new MutableBlockVector2D();
        return super.setExtent(extent);
    }
}