svg-path-properties

Pure Javascript alternative to getPointAtLength(t) and getTotalLength() functions. Works with Canvas and Node

JavaScript can access to path elements properties in a browser, such as its length and the point at a given length. Unfortunately, this can't be achieved using a Canvas element or when working with node. This library can be used to replace this need. It has no dependencies on other JavaScript libraries.

INSTALL

To use with npm, just type

npm install svg-path-properties

USAGE

var path = require("svg-path-properties");
var properties = path.svgPathProperties("M0,100 Q50,-50 100,100 T200,100");
var length = properties.getTotalLength();
var point = properties.getPointAtLength(200);
var tangent = properties.getTangentAtLength(200);
var allProperties = properties.getPropertiesAtLength(200);

Check this block to see how it works with the browser.

CREDITS

Some parts of the code are taken from other libraries or questions at StackOverflow:

For Bézier curves:

• http://bl.ocks.org/hnakamur/e7efd0602bfc15f66fc5, https://gist.github.com/tunght13488/6744e77c242cc7a94859
• http://stackoverflow.com/questions/11854907/calculate-the-length-of-a-segment-of-a-quadratic-bezier
• http://pomax.github.io/bezierinfo

For path parsing:

• https://github.com/jkroso/parse-svg-path