nD cubic & quadratic curve analysis, conversion, interpolation, splitting
npm install @thi.ng/geom-splines
!npm downloads

> [!NOTE]
> This is one of 214 standalone projects, maintained as part
> of the @thi.ng/umbrella monorepo
> and anti-framework.
>
> 🚀 Please help me to work full-time on these projects by sponsoring me on
> GitHub. Thank you! ❤️
- About
- Status
- Related packages
- Installation
- Dependencies
- Usage examples
- API
- Cubic curve conversion from polygons & polylines
- Poly vertices as control points
- Poly vertices as break points
- Authors
- License
nD cubic & quadratic curve analysis, conversion, interpolation, splitting. This is a support package for @thi.ng/geom.
Current implementations partially based on
toxiclibs (Java) and Clojure version of
thi.ng/geom.
STABLE - used in production
Search or submit any issues for this package
- @thi.ng/geom-subdiv-curve - Freely customizable, iterative nD subdivision curves for open / closed geometries
``bash`
yarn add @thi.ng/geom-splines
ESM import:
`ts`
import * as gs from "@thi.ng/geom-splines";
Browser ESM import:
`html`
For Node.js REPL:
`js`
const gs = await import("@thi.ng/geom-splines");
Package sizes (brotli'd, pre-treeshake): ESM: 2.79 KB
- @thi.ng/api
- @thi.ng/checks
- @thi.ng/geom-arc
- @thi.ng/geom-resample
- @thi.ng/math
- @thi.ng/vectors
Note: @thi.ng/api is in _most_ cases a type-only import (not used at runtime)
One project in this repo's
/examples
directory is using this package:
| Screenshot | Description | Live demo | Source |
|:-------------------------------------------------------------------------------------------------------------------|:--------------------------------------------------|:--------------------------------------------------|:-------------------------------------------------------------------------------|
|
| Polygon to cubic curve conversion & visualization | Demo | Source |
Currently, there're two ways to convert a polygon/polyline into a
sequence of cubic curve segments. Both modes support customizable curve
tightness.
Furthermore, both conversion modes can be instructed to use uniformly
scaled control point tangents: In uniform mode, the tangents have a
uniform, user defined length, resulting in equidistant control points
for each poly vertex. In non-uniform mode, each tangent is scaled by the
length of its parent poly edge.
#### Poly vertices as control points
In this mode the curve always goes through the midpoints each polygon
edge, with the original polygon vertices being used to compute control
points.
| Proportional tangent scale | Uniform tangent scale |
|------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------|
|  |  |
#### Poly vertices as break points
In this mode the curve always goes through the original polygon vertices
and additional control points are created via symmetric tangents at each
poly vertex. The tangents themselves are computed via the bisector of
each vertex corner, taking into the convexity of each poly vertex.
| Proportional tangent scale | Uniform tangent scale |
|------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------|
|  |  |
If this project contributes to an academic publication, please cite it as:
`bibtex``
@misc{thing-geom-splines,
title = "@thi.ng/geom-splines",
author = "Karsten Schmidt",
note = "https://thi.ng/geom-splines",
year = 2016
}
© 2016 - 2026 Karsten Schmidt // Apache License 2.0