public class WorldGenTwigsAndRocks extends WorldGenerator {
    private Block getBlock;
    private IBlockState state;

    public WorldGenTwigsAndRocks(Block setBlock) {
        this.getBlock = setBlock;
        this.state = setBlock.getDefaultState();
    }

    public boolean generate(World worldIn, Random rand, BlockPos position) {
        for (int i = 0; i < 32; i++) {
            BlockPos blockpos = position.add(rand.nextInt(8) - rand.nextInt(8), rand.nextInt(4) - rand.nextInt(4), rand.nextInt(8) - rand.nextInt(8));
            IBlockState getBlockState = worldIn.getBlockState(blockpos.down());
            Material getMaterial = getBlockState.getMaterial();

            if (worldIn.isAirBlock(blockpos) && blockpos.getY() < 255 && blockpos.getY() > 0 && (getMaterial == Material.GRASS || getMaterial == Material.CLAY || getMaterial == Material.GROUND || getMaterial == Material.ROCK || getMaterial == Material.SAND) && !worldIn.isAirBlock(blockpos.down())) {
                worldIn.setBlockState(blockpos, state, 2);
            }
        }
        return true;
    }

    public int offset(int bound, Random rand) {
        return rand.nextInt(bound * 2) - bound;
    }
}