--- layout: api title: "v2.1.5 JavaScript Library: L.LineUtil" categories: api version: v2.1.5 permalink: /api/v2.1.5/l-lineutil ---

## LineUtil

Various utility functions for polyine points processing, used by Leaflet internally to make polylines lightning-fast.

### Methods

Method | Returns | Description
--- | --- | ---
`simplify( <Point[]> points, <Number> tolerance )` | `Point[]` | Dramatically reduces the number of points in a polyline while retaining its shape and returns a new array of simplified points. Used for a huge performance boost when processing/displaying Leaflet polylines for each zoom level and also reducing visual noise. `tolerance` affects the amount of simplification (lesser value means higher quality but slower and with more points). Also released as a separated micro-library Simplify.js.
`pointToSegmentDistance( <Point> p, <Point> p1, <Point> p2 )` | `Number` | Returns the distance between point `p` and segment `p1` to `p2`.
`closestPointOnSegment( <Point> p, <Point> p1, <Point> p2 )` | `Point` | Returns the closest point from a point `p` on a segment `p1` to `p2`.
`clipSegment( <Point> a, <Point> b, <Bounds> bounds )` | `-` | Clips the segment `a` to `b` by rectangular bounds (modifying the segment points directly!). Used by Leaflet to only show polyline points that are on the screen or near, increasing performance.