Bitmap

A fixed number of on/off bits, numbered from 0. The width is the Bits passed to Bitmap.new. An index outside 0 to Bits - 1 is ignored: Set, Clear and Toggle do nothing, and Test returns false.

local Seen = Collections.Bitmap.new({ Bits = 64 })
Seen:Set(3)
print(Seen:Test(3), Seen:PopCount()) -- true 1

Summary

Member	Description
.new()	Creates a bitmap of Bits bits, all off.
:Set()	Turns the bit at Index on.
:Clear()	Turns the bit at Index off.
:Toggle()	Flips the bit at Index.
:Test()	Whether the bit at Index is on.
:ClearAll()	Turns every bit off.
:SetAll()	Turns every bit on.
:PopCount()	How many bits are on.
:Raw()	Returns the buffer that holds the bits.

Functions

new

function Bitmap.new(Config: { Bits: number }): Bitmap

Creates a bitmap of Bits bits, all off. Its width cannot change later.

Methods

Set

function Bitmap:Set(Index: number)

Turns the bit at Index on.

Clear

function Bitmap:Clear(Index: number)

Turns the bit at Index off.

Toggle

function Bitmap:Toggle(Index: number)

Flips the bit at Index.

Test

function Bitmap:Test(Index: number): boolean

Whether the bit at Index is on.

ClearAll

function Bitmap:ClearAll()

Turns every bit off.

SetAll

function Bitmap:SetAll()

Turns every bit on.

PopCount

function Bitmap:PopCount(): number

How many bits are on.

Raw

function Bitmap:Raw(): buffer

Returns the buffer that holds the bits. Bit i is bit i % 32 of the u32 at byte (i // 32) * 4, and the bits past the width stay off.