LerpAlike

LerpAlike is a term used in programming to describe a family of interpolation utilities that behave similarly to linear interpolation (lerp) but incorporate non-linear progression or additional controls. At its core, a standard lerp computes a value between two endpoints a and b using a parameter t in the range [0, 1] as (1 - t) a + t b. LerpAlike extends this idea by transforming or augmenting the interpolation parameter before applying the linear blend.

Common forms of lerpAlike include applying a function to t, such as an easing curve, to produce t' before blending. This allows non-linear timing while preserving the basic endpoint interpolation. Variants may clamp t', handle extrapolation, or integrate piecewise or multi-dimensional interpolation. The result is a value that remains between a and b (when clamped) and varies smoothly with t, but the rate of change can accelerate, decelerate, or follow a custom profile.

Typical use cases appear in animation, UI transitions, color and vector blending, and shader code, where a non-linear or adjustable progression is desirable without abandoning the familiar lerp interface. Implementations often expose parameters to control the transformation of t, such as an easing function, a smoothstep or smootherstep operator, or an exponent. A basic pattern is to compute t' = transform(t) and then return (1 - t') a + t' b, optionally clamped to [0, 1].

Considerations when using lerpAlike include preserving monotonicity, bounding results within the intended range, and choosing transformations that match the desired visual or physical effect. The term is not a formal standard but a descriptive label for lerp-like methods with added flexibility.