Direction.java

package io.vivarium.core;

public enum Direction
{
    NORTH, EAST, SOUTH, WEST;

    public static int getHorizontalComponent(Direction direction)
    {
        switch (direction)
        {
            case EAST:
                return (1);
            case WEST:
                return (-1);
            case NORTH:
            case SOUTH:
                return (0);
        }
        throw new Error("Null Direction");
    }

    public static int getVerticalComponent(Direction direction)
    {
        switch (direction)
        {
            case NORTH:
                return (-1);
            case SOUTH:
                return (1);
            case EAST:
            case WEST:
                return (0);
        }
        throw new Error("Null Direction");
    }

    public static Direction stepCounterclockwise(Direction direction)
    {
        switch (direction)
        {
            case NORTH:
                return (WEST);
            case EAST:
                return (NORTH);
            case SOUTH:
                return (EAST);
            case WEST:
                return (SOUTH);
        }
        return null;
    }

    public static Direction stepClockwise(Direction direction)
    {
        switch (direction)
        {
            case NORTH:
                return (EAST);
            case EAST:
                return (SOUTH);
            case SOUTH:
                return (WEST);
            case WEST:
                return (NORTH);
        }
        return null;
    }

    public static Direction flipDirection(Direction direction)
    {
        switch (direction)
        {
            case NORTH:
                return (SOUTH);
            case EAST:
                return (WEST);
            case SOUTH:
                return (NORTH);
            case WEST:
                return (EAST);
        }
        return null;
    }

    public static double getRadiansFromNorth(Direction direction)
    {
        switch (direction)
        {
            case NORTH:
                return (0);
            case WEST:
                return (Math.PI / 2);
            case SOUTH:
                return (Math.PI);
            case EAST:
                return (Math.PI * 3 / 2);
        }
        return Double.NaN;
    }
}