Class: Interpolator<Field>

Defined in: client/interpolate.ts:15

Smooths values that arrive once per tick, for drawing between ticks.

State sync delivers positions 10 to 30 times a second; a screen draws 60 or more. Each time a new value arrives for an id, the interpolator glides to it from wherever that id was being drawn, over durationMs (one tick is the usual choice). Because it always starts from what is on screen, a late or bunched update bends the motion instead of making it jump.

const glide = new Interpolator(1000 / client.tickRate, ["x", "y"]);
onState: (state) => glide.update(state.units),
// in the render loop:
const { x, y } = glide.at(id) ?? state.units[id];

Type Parameters

Type Parameter
Field extends string

Constructors

Constructor

new Interpolator<Field>(durationMs, fields): Interpolator<Field>;

Defined in: client/interpolate.ts:24

Parameters

Parameter	Type	Description
durationMs	number	how long a glide takes, usually the time between ticks
fields	readonly Field[]	the numeric fields to smooth, e.g. ["x", "y"]

Returns

Interpolator<Field>

Methods

update()

update(targets, now?): void;

Defined in: client/interpolate.ts:33

Feed the latest values, keyed by id. Ids missing from targets are forgotten; new ones start at their target.

Parameters

Parameter	Type
targets	Record<string, Record<Field, number>>
now?	number

Returns

void

---

at()

at(id, now?): Record<Field, number> | undefined;

Defined in: client/interpolate.ts:45

The values to draw for id right now, or undefined if it is not known.

Parameters

Parameter	Type
id	string
now?	number

Returns

Record<Field, number> | undefined

---

clear()

clear(): void;

Defined in: client/interpolate.ts:57

Forget everything, e.g. after moving to another room.

Returns

void