de.ellpeck.rockbottom.api.util

Class Util

java.lang.Object

de.ellpeck.rockbottom.api.util.Util

public final class Util
extends java.lang.Object

This class provides a large variety of helpful utility methods and variables that can be useful in a multitude of circumstances.

Field Summary

Fields

Modifier and Type	Field and Description
static com.google.gson.Gson	GSON A global instance of google gson' gson that can be used to serialize and deserialize json objects.
static com.google.gson.JsonParser	JSON_PARSER A global instance of google gson's json parser that can be used to parse jsons into easily modifyable and queryable json objects.
static java.util.Random	RANDOM A global random with a randomized seed that can be used for operations that are not based on the world seed.

Constructor Summary

Constructors

Constructor and Description
Util()

Method Summary

Modifier and Type	Method and Description
static int	ceil(double value) This is a faster implementation of Math.ceil(double), in that it simply typecasts the given value and then adjusts it accordingly.
static double	clamp(double num, double min, double max) Clamps a value between a minimum and a maximum value.
static int	clamp(int num, int min, int max) Clamps a value between a minimum and a maximum value.
static boolean	createAndOpen(java.io.File file) Creates a file if it doesn't exist and then opens it with the operating system's default file opening software.
static Entity	createEntity(ResourceName name, IWorld world) Creates an entity from its entity registry name and with the given world.
static void	deleteFolder(java.io.File file) A helper method to recursively delete a folder and all of its contents.
static double	distance(double x1, double y1, double x2, double y2) Returns the absolute distance between two points using the Pythagorean theorem.
static double	distanceSq(double x1, double y1, double x2, double y2) Returns the squared distance between two points using the Pythagorean theorem.
static int	floor(double value) This is a faster implementation of Math.floor(double), in that it simply typecasts the given value and then adjusts it accordingly.
static long	getTimeMillis() Gets the system time in milliseconds.
static boolean	isResourceName(java.lang.String s) Utility method to figure out if a string is a resource name, meaning if it contains a Constants.RESOURCE_SEPARATOR that is not at the beginning or end of the string.
static double	lerp(double pos1, double pos2, double factor)
static java.util.List<java.lang.Integer>	makeIntList(int start, int end) Creates a list of integers starting at the first number and ending at the second number.
static boolean	openWebsite(java.lang.String domain) Opens a website in the operating system's default browser.
static long	scrambleSeed(int i) Scrambles a single value into a seed that can be used for world gen.
static long	scrambleSeed(int x, int y) Scrambles an x and a y value together into a seed that can be used for world gen.
static long	scrambleSeed(int x, int y, long seed) Scrambles an x and a y value into a seed based on a different seed.
static long	scrambleSeed(int i, long seed) Scrambles a value into a seed based on a different seed.
static long	shiftScramble(long l) Scrambles a seed in a predictable, always-equal, but seemingly random way, making the output seem like a completely different number.
static void	sleepSafe(long time) Causes the current thread to sleep by the given amount of milliseconds, ignoring any interruptions that might be thrown.
static int	toGridPos(double worldPos) Converts a given position in the world to a chunk grid position.
static int	toWorldPos(int gridPos) Converts a given position of a chunk into its world position.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

RANDOM

public static final java.util.Random RANDOM

A global random with a randomized seed that can be used for operations that are not based on the world seed. Note that, when doing something like world generation, the world's IChunkOrWorld.getSeed() should always be used. For that, there are several utility methods at the bottom of this class to help modify the world seed in a predictable pattern.

See Also:

IChunkOrWorld.getSeed(), scrambleSeed(int, long)

GSON

public static final com.google.gson.Gson GSON

A global instance of google gson' gson that can be used to serialize and deserialize json objects. This instance has pretty printing turned on, meaning any JSONs that are created with it will look easily readable and will not be a single line.

JSON_PARSER

public static final com.google.gson.JsonParser JSON_PARSER

A global instance of google gson's json parser that can be used to parse jsons into easily modifyable and queryable json objects.

Constructor Detail

Util

public Util()

Method Detail

distance

public static double distance(double x1,
                              double y1,
                              double x2,
                              double y2)

Returns the absolute distance between two points using the Pythagorean theorem. Note that, if you want to just compare distances and don't care about the actual, absolute value of the distance, it is a lot faster to use distanceSq(double, double, double, double).

Parameters:

x1 - The first point's x

y1 - The first point's y

x2 - The second point's x

y2 - The second point's y

Returns:

The distance

See Also:

distanceSq(double, double, double, double)

distanceSq

public static double distanceSq(double x1,
                                double y1,
                                double x2,
                                double y2)

Returns the squared distance between two points using the Pythagorean theorem.

Parameters:

x1 - The first point's x

y1 - The first point's y

x2 - The second point's x

y2 - The second point's y

Returns:

The squared distance

See Also:

distance(double, double, double, double)

lerp

public static double lerp(double pos1,
                          double pos2,
                          double factor)

clamp

public static double clamp(double num,
                           double min,
                           double max)

Clamps a value between a minimum and a maximum value. If the given value is higher than the maximum, the maximum will be returned. If it is lower than the minimum, the minimum will be returned. Else, the actual value will be returned.

Parameters:

num - The number to clamp

min - The minimum

max - The maximum

Returns:

The clamped number

See Also:

clamp(int, int, int)

clamp

public static int clamp(int num,
                        int min,
                        int max)

Clamps a value between a minimum and a maximum value. If the given value is higher than the maximum, the maximum will be returned. If it is lower than the minimum, the minimum will be returned. Else, the actual value will be returned.

Parameters:

num - The number to clamp

min - The minimum

max - The maximum

Returns:

The clamped number

See Also:

clamp(double, double, double)

floor

public static int floor(double value)

This is a faster implementation of Math.floor(double), in that it simply typecasts the given value and then adjusts it accordingly. This results in the integer that is closest to the given value (in the direction of 0) will be returned.

Parameters:

value - The value to floor

Returns:

The floored value

ceil

public static int ceil(double value)

This is a faster implementation of Math.ceil(double), in that it simply typecasts the given value and then adjusts it accordingly. This results in the integer that is closest to the given value (in the direction of negative infinity, if the input is negative, or positive infinity otherwise) will be returned.

Parameters:

value - The value to ceiling

Returns:

The ceilinged value

toGridPos

public static int toGridPos(double worldPos)

Converts a given position in the world to a chunk grid position. In other words, giving any position in the world to this method will return the position of the chunk that this position would be in.

Parameters:

worldPos - The world position

Returns:

The chunk position

See Also:

IChunk.getGridX(), IChunk.getGridY()

toWorldPos

public static int toWorldPos(int gridPos)

Converts a given position of a chunk into its world position. In other words, giving any chunk's grid position to this method will return the position of the chunk in the world.

Parameters:

gridPos - The chunk grid position

Returns:

The world position

deleteFolder

public static void deleteFolder(java.io.File file)

A helper method to recursively delete a folder and all of its contents. Just calling File.delete() will fail if it is a folder that contains other files, so this method clears all of the files in a folder first before deleting it.

Parameters:

file - The folder to delete

createEntity

public static Entity createEntity(ResourceName name,
                                  IWorld world)

Creates an entity from its entity registry name and with the given world.

Parameters:

name - The registry name of the entity

world - The world that the entity should be in

Returns:

The newly created entity

See Also:

Registries.ENTITY_REGISTRY

getTimeMillis

public static long getTimeMillis()

Gets the system time in milliseconds. This is merely to shorten the long call to System.currentTimeMillis() to a more sensible amount of characters.

Returns:

The system time in milliseconds

createAndOpen

public static boolean createAndOpen(java.io.File file)

Creates a file if it doesn't exist and then opens it with the operating system's default file opening software. This is a utility method as usually, just using Desktop.open(File) would cause an exception if the folder does not exist

Parameters:

file - The file to open

Returns:

True if it worked, false if some exception was thrown

openWebsite

public static boolean openWebsite(java.lang.String domain)

Opens a website in the operating system's default browser. This is a utility method as Desktop.browse(URI) can throw an exception.

Parameters:

domain - The domain to open

Returns:

True if it worked, false if some exception was thrown

shiftScramble

public static long shiftScramble(long l)

Scrambles a seed in a predictable, always-equal, but seemingly random way, making the output seem like a completely different number. This can be used for world generation when you need a different seed that, nevertheless, should still be influenced by the world's seed. To scramble a seed based on some other value, see scrambleSeed(int, long).

Parameters:

l - The long to scramble

Returns:

The scrambled long

See Also:

IChunkOrWorld.getSeed(), scrambleSeed(int, long)

scrambleSeed

public static long scrambleSeed(int x,
                                int y)

Scrambles an x and a y value together into a seed that can be used for world gen. Note that this is not influenced by another seed. Obviously, these values do not have to be actual positions in the world, but can just be two arbitrary numbers.

Parameters:

x - The x value

y - The y value

Returns:

The seed

scrambleSeed

public static long scrambleSeed(int i)

Scrambles a single value into a seed that can be used for world gen. Note that this is not influenced by another seed.

Parameters:

i - The value

Returns:

The seed

scrambleSeed

public static long scrambleSeed(int x,
                                int y,
                                long seed)

Scrambles an x and a y value into a seed based on a different seed. This can be used for world gen. Obviously, these values do not have to be actual positions in the world, but can just be two arbitrary numbers.

Parameters:

x - The x value

y - The y value

seed - The original seed

Returns:

The new seed

scrambleSeed

public static long scrambleSeed(int i,
                                long seed)

Scrambles a value into a seed based on a different seed. This can be used for world gen.

Parameters:

i - The value

seed - The original seed

Returns:

The new seed

makeIntList

public static java.util.List<java.lang.Integer> makeIntList(int start,
                                                            int end)

Creates a list of integers starting at the first number and ending at the second number. This can be especially useful for creating IFilteredInventory instances with a lot of slots.

Parameters:

start - The first number (inclusive)

end - The second number (exclusive)

Returns:

A list of integers

See Also:

IFilteredInventory.getInputSlots(ItemInstance, Direction), IFilteredInventory.getOutputSlots(Direction)

isResourceName

public static boolean isResourceName(java.lang.String s)

Utility method to figure out if a string is a resource name, meaning if it contains a Constants.RESOURCE_SEPARATOR that is not at the beginning or end of the string.

Parameters:

s - The string to check

Returns:

If the string is a resource name

sleepSafe

public static void sleepSafe(long time)

Causes the current thread to sleep by the given amount of milliseconds, ignoring any interruptions that might be thrown. This is a helper method to reduce the amount of space that a try-catch statement takes up in code.

Parameters:

time - The time to sleep for