Class KeyDesign

A design for octant keys.

3D coordinates are packed into a single integer to obtain a unique key. This class describes the bit allotment for each coordinate and provides methods for key packing and unpacking.

See KeyDesign.BITS for the total amount of available bits.

Hierarchy

Constructors

constructor

Properties

BITS HI_BITS LO_BITS

Accessors

rangeX rangeXY rangeY rangeZ x y z

Methods

calculateBounds equals getMaxKeyCoordinates getMinKeyCoordinates keyRange packKey set toString unpackKey

Events

EVENT_CHANGE

Constructors

constructor

  • new KeyDesign(x?, y?, z?): KeyDesign

  • Constructs a new key design.

    Parameters

    • x: number = 8

      The amount of bits used for the X-coordinate.

    • y: number = x

      The amount of bits used for the Y-coordinate.

    • z: number = x

      The amount of bits used for the Z-coordinate.

    Returns KeyDesign

Properties

Static Readonly BITS

BITS: 53 = BITS

The total amount of available bits for safe integers.

JavaScript uses IEEE 754 binary64 Doubles for all numbers and, as a result, only supports 53-bit Integers natively.

BigInt is not an option due to the following reasons:

  • operations on BigInt are not constant time (unpredictable performance)
  • only supports signed integers (no >>> operator)

For more information see: http://2ality.com/2012/04/number-encoding.html

Static Readonly HI_BITS

HI_BITS: 21 = HI_BITS

The amount of available bits in the high DWord (21).

In JavaScript, bit operations can only be applied to DWords (32-bit). All 53-bit keys must be split into a high and a low part for processing.

Static Readonly LO_BITS

LO_BITS: 32 = LO_BITS

The amount of available bits in the low DWord (32).

In JavaScript, bit operations can only be applied to DWords (32-bit). All 53-bit keys must be split into a high and a low part for processing.

Accessors

rangeX

  • get rangeX(): number

  • The amount of distinct integers that can be represented with X bits.

    Returns number

rangeXY

  • get rangeXY(): number

  • The amount of distinct integers that can be represented with X + Y bits.

    Returns number

rangeY

  • get rangeY(): number

  • The amount of distinct integers that can be represented with Y bits.

    Returns number

rangeZ

  • get rangeZ(): number

  • The amount of distinct integers that can be represented with Z bits.

    Returns number

x

  • get x(): number

  • The amount of bits reserved for the X-coordinate.

    Returns number

y

  • get y(): number

  • The amount of bits reserved for the Y-coordinate.

    Returns number

z

  • get z(): number

  • The amount of bits reserved for the Z-coordinate.

    Returns number

Methods

calculateBounds

  • calculateBounds(cellSize, target): Box3

  • Calculates the bounds that contain the domain of this key design.

    The center of the bounds is (0, 0, 0).

    Parameters

    • cellSize: Vector3

      The cell size.

    • target: Box3

      A box to store the result in.

    Returns Box3

    The bounds.

equals

  • equals(keyDesign): boolean

  • Checks if this key design equals another key design.

    Parameters

    Returns boolean

    Whether this key design equals the given one.

getMaxKeyCoordinates

getMinKeyCoordinates

keyRange

  • keyRange(min, max): KeyIterator

  • Returns a new key range iterator.

    The iterator returns all keys in the specified coordinate range, including those at min and max.

    Parameters

    • min: Vector3

      The lower key index bounds (zero-based uint coordinates).

    • max: Vector3

      The upper key index bounds (zero-based uint coordinates).

    Returns KeyIterator

    An iterator.

packKey

  • packKey(x, y, z): number

  • Packs key coordinates into a unique key.

    Parameters

    • x: number

      The X-coordinate (Uint).

    • y: number

      The Y-coordinate (Uint).

    • z: number

      The Z-coordinate (Uint).

    Returns number

    The key.

    Throws

    If any value is out of bounds.

set

  • set(x, y, z): void

  • Sets the bit distribution.

    Parameters

    • x: number

      The amount of bits used for the X-coordinate.

    • y: number

      The amount of bits used for the Y-coordinate.

    • z: number

      The amount of bits used for the Z-coordinate.

    Returns void

    Throws

    If the bit allotment is invalid.

toString

  • toString(): string

  • Converts the information of this key design into a string.

    Returns string

    The key design as a string.

unpackKey

  • unpackKey(key, target): Vector3

  • Extracts the 3D coordinates from a given key.

    Parameters

    • key: number

      The key.

    • target: Vector3

      A vector to store the result in.

    Returns Vector3

    The extracted key coordinates.

Events

Static Readonly EVENT_CHANGE

EVENT_CHANGE: "change" = "change"

Triggers when a key design has changed.

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