Finding relative direction between two BlockPos, assuming they are neighbors

RelativeDirection.java

// Inlined because apparently applications of pure function with constants are not considered constants
private static final int DOWN_BITS = 0b010100; // calculateDirectionBits(0, -1, 0)
private static final int UP_BITS = 0b010110; // calculateDirectionBits(0, 1, 0)
private static final int NORTH_BITS = 0b010001; // calculateDirectionBits(0, 0, -1)
private static final int SOUTH_BITS = 0b011001; // calculateDirectionBits(0, 0, 1)
private static final int WEST_BITS = 0b000101; // calculateDirectionBits(-1, 0, 0)
private static final int EAST_BITS = 0b100101; // calculateDirectionBits(1, 0, 0)

private static int calculateDirectionBits(int dx, int dy, int dz) {
    // Add 1 to make all offsets positive to avoid dealing with complement bits
    return ((dx + 1) << 4) | ((dz + 1) << 2) | (dy + 1);
}

public static Direction relativeDirection(BlockPos center, BlockPos neighbor) {
    int dx = neighbor.getX() - center.getX();
    int dy = neighbor.getY() - center.getY();
    int dz = neighbor.getZ() - center.getZ();
    switch (calculateDirectionBits(dx, dy, dz)) {
        case DOWN_BITS:
            return Direction.DOWN;
        case UP_BITS:
            return Direction.UP;
        case NORTH_BITS:
            return Direction.NORTH;
        case SOUTH_BITS:
            return Direction.SOUTH;
        case WEST_BITS:
            return Direction.WEST;
        case EAST_BITS:
            return Direction.EAST;
    }
    return null;
}