JSPM

polyline-normals

1.0.2
  • ESM via JSPM
  • ES Module Entrypoint
  • Export Map
  • Keywords
  • License
  • Repository URL
  • TypeScript Types
  • README
  • Created
  • Published
  • Downloads 60004
  • Score
    100M100P100Q162590F
  • License MIT

gets miter normals for a 2D polyline

Package Exports

  • polyline-normals

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (polyline-normals) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

polyline-normals

stable

img

Computes the normals of a polyline, using miter joins where multiple segments meet. This is mainly useful to expand thick lines in a vertex shader on the GPU. 

var getNormals = require('polyline-normals')

//a triangle, closed
var path = [ [0, 122], [0, 190], [90, 190], [0, 122] ]

//get the normals
var normals = getNormals(path)

//now draw our thick line in 2D/3D/etc

See the 2d test for an example of how these lines would be extruded.

For more complex line joins and end caps, see extrude-polyline (which builds an indexed mesh).

ThreeJS Example

Coming soon.

Usage

NPM

normals(path)

For the given path, produces a new array of the same length with normal information for each point. The data contains a normal, [nx, ny] and the length of the miter (default to 1.0 where no join occurs). 

[ 
    [ [nx, ny], miterLength ],
    [ [nx, ny], miterLength ]
]

License

MIT, see LICENSE.md for details.