README
¶
pgen
Overview
A Go package for deterministic generation of random-like numbers.
This package is designed for simulations and procedural generation where you need to generate random-like features from a known seed.
A standard number generator produces random numbers in a sequence so if a code refactor changes the order in which you call the rng you'll get a different result. pgen allows you to specify which number in the random sequence is to be used for a specific procedurally generated feature. This preserves behaviour even if code refactoring changes the order in which the simulation is generated.
Installation
Simply run the following in your module:
go get github.com/iand/pgen
Documentation is at http://godoc.org/github.com/iand/pgen
Usage
Example of a procedural level generator:
package main
import (
"github.com/iand/pgen"
"math/rand"
)
// generateLevel generates a new game level based on the level seed. It will always
// generate the same level no matter how many other levels were generated before
// or if the order of generation is changed.
func generateLevel(levelSeed int64) {
// These constants control which random number is returned by the generator
const (
numberOfPits = iota
numberOfEnemies
spawnPointX
spawnPointY
legendaryLootChance
)
gen := pgen.New(levelSeed)
// Generate up to 8 pits
for i := 0; i < gen.Intn(numberOfPits, 8) {
generatePit()
}
// Generate up to 4 enemies
for i := 0; i < gen.Intn(numberOfEnemies, 4) {
generateEnemy()
}
// Starting location on the 64x64 grid
x, y := gen.Intn(spawnPointX,64), gen.Intn(spawnPointY,64)
placePlayer(x, y)
// Is there a legendary item?
if rand.Float64() <= gen.Intn(legendaryLootChance).Float64() {
placeLoot()
}
}
License
This is free and unencumbered software released into the public domain. For more
information, see http://unlicense.org/ or the accompanying UNLICENSE file.
Documentation
¶
Overview ¶
Package pgen is a package for deterministic generation of random-like numbers.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Gen ¶
type Gen int64
A Gen is a deterministic generator of random-like numbers.
func (Gen) Float32 ¶
Float32 generates the random number for index i and converts it to a float32 in the range [0,1).
func (Gen) Float64 ¶
Float64 generates the random number for index i and converts it to a float64 in the range [0,1).
func (Gen) Int32 ¶
Int32 generates the random number for index i. It returns integers in the range [0,2^31-1].
func (Gen) Int64 ¶
Int64 generates the random number for index i. It returns integers in the range [0,2^63-1].
func (Gen) Int64n ¶ added in v0.0.3
Int64n generates the random number for index i using 64 bits. It returns integers in the range [0,n).
func (Gen) Intn ¶
Intn generates the random number for index i. It returns integers in the range [0,n).
Source Files