lerp

Linearly interpolates between start and end by the factor t.

• t = 0 returns start.
• t = 1 returns end.
• Values of t outside [0, 1] extrapolate beyond the range.

Available since v2.0.0

Import

import { lerp } from '@helpers4/number';
// or, from the all-in-one package (same code, one install):
import { lerp } from 'helpers4/number';

Signature

lerp(start: number, end: number, t: number): number

Parameters

Parameter	Type	Description
start	number	The start value.
end	number	The end value.
t	number	The interpolation factor.

Returns

number — The interpolated value.

Examples

Interpolate between two values

Returns the value between start and end at position t (0 = start, 1 = end).

lerp(0, 100, 0)    // => 0
lerp(0, 100, 0.5)  // => 50
lerp(0, 100, 1)    // => 100

Animate a colour channel

t outside [0, 1] extrapolates beyond the range.

lerp(0, 255, 0.5) // => 127.5
lerp(0, 10, 2)    // => 20  (extrapolation)

Source

View source on GitHub