@darkforest_eth/hashing

This package contains MiMC hashing utilities for use with Dark Forest. The MiMC algorithm is used for both finding planet hashes and calculating the perlin in-game. Among other things, these values are often needed for generating Snarks.

Installation

You can install this package using npm or yarn by running:

npm install --save @darkforest_eth/hashing

yarn add @darkforest_eth/hashing

When using this in a plugin, you might want to load it with skypack

import * as hashing from 'http://cdn.skypack.dev/@darkforest_eth/hashing';

Table of contents

Interfaces

• IntegerVector

Variables

• Fraction
• MAX_PERLIN_VALUE

Functions

• getRandomGradientAt
• mimcHash
• mimcSponge
• modPBigInt
• modPBigIntNative
• perlin
• rand
• seededRandom

Variables

Fraction

• Fraction: IFraction

---

MAX_PERLIN_VALUE

• Const MAX_PERLIN_VALUE: 32

Functions

getRandomGradientAt

▸ getRandomGradientAt(point, scale, randFn): Vector

Parameters

Name	Type
point	Vector
scale	IFraction
randFn	HashFn

Returns

Vector

---

mimcHash

▸ mimcHash(key): (...inputs: number[]) => BigInteger

The primary function used to build any MiMC hashing algorithm for Dark Forest.

Parameters

Name	Type	Description
key	number	The key for the MiMC algorithm. Will usually be PLANETHASH_KEY, SPACETYPE_KEY, or BIOMEBASE_KEY.

Returns

fn

▸ (...inputs): BigInteger

Parameters

Name	Type
...inputs	number[]

Returns

BigInteger

---

mimcSponge

▸ mimcSponge(inputs, nOutputs, rounds, key): BigInteger[]

Parameters

Name	Type
inputs	BigInteger[]
nOutputs	number
rounds	number
key	number

Returns

BigInteger[]

---

modPBigInt

▸ modPBigInt(x): BigInteger

Modulo a number with the LOCATION_ID_UB constant. If the result is < 0, the LOCATION_ID_UB will then be added.

Parameters

Name	Type	Description
x	number	The number to modulo against LOCATION_ID_UB

Returns

BigInteger

---

modPBigIntNative

▸ modPBigIntNative(x): BigInteger

Modulo a BigInt with the LOCATION_ID_UB constant. If the result is < 0, the LOCATION_ID_UB will then be added.

Parameters

Name	Type	Description
x	BigInteger	The number to modulo against LOCATION_ID_UB

Returns

BigInteger

---

perlin

▸ perlin(coords, options): number

Calculates the perlin for a location, given the x,y pair and the PerlinConfig for the game.

Parameters

Name	Type	Description
coords	IntegerVector	An object of the x,y coordinates for which perlin is being calculated.
options	PerlinConfig	An object containing the configuration for the perlin algorithm.

Returns

number

---

rand

▸ rand(key): (...args: number[]) => number

Parameters

Name	Type
key	number

Returns

fn

▸ (...args): number

Parameters

Name	Type
...args	number[]

Returns

number

---

seededRandom

▸ seededRandom(seed): number

Generate a random number based on some seed. Useful for procedural generation.

Parameters

Name	Type	Description
seed	number	The seed of the random number.

Returns

number