svg-path-properties

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);
var parts = properties.getParts(); --> Gets an array with the different sections of the path, each element containing the initial and final points, the length and the curve function

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

The TypeScript declaration file is available too, since version 0.5

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
• Arc elements calculation: https://github.com/MadLittleMods/svg-curve-lib/tree/f07d6008a673816f4cb74a3269164b430c3a95cb

For path parsing:

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