svg-path-utils

Some utilities for svg path element to help operating with path data, like calculating inverse path data...

Install

npm install svg-path-utils

Usage

var spu = require('svg-path-utils');
var utils = new spu.SVGPathUtils();

or in es6

import {SVGPathUtils} from 'svg-path-utils';
const utils = new SVGPathUtils();

then

// generate path data
const d = utils.join(utils.M(50,100), utils.L(200,300), utils.Z()); // d = "M50,100 L200,300 Z"
 
// calculate inverse path data
const inverse_d = utils.inversePath(d); // inverse_d = "M200,300 L50,100 Z"

Example

Inverse path data calculation

Direct Path	Inverse Path
d="M50,300 L50,250 C50,150 75,150 100,250 C150,450 200,450 200,250 Q200,100 400,100"	d="M400,100 Q200,100 200,250 C200,450 150,450 100,250 C75,150 50,150 50,250 L50,300"

Check this online demo.

It is also used in Yarrow.

API Reference

Path data commands (operators)

Uppercase (M, L, H, ...) - uses absolute coordinates, lowercase (m, l, h, ...) - uses relative coordinates

# utils.M(x, y) - “moveto” commands.

# utils.m(x, y)

# utils.L(x, y) - “lineto” commands.

# utils.l(x, y)

# utils.H(x) - horizontal “lineto” commands.

# utils.h(x)

# utils.V(y) - vertical “lineto” commands.

# utils.v(y)

# utils.C(x1, y1, x2, y2, x, y) - cubic Bézier curve commands.

# utils.c(x1, y1, x2, y2, x, y)

# utils.S(x2, y2, x, y) - smooth cubic Bézier curve commands.

# utils.s(x2, y2, x, y)

# utils.Q(x1, y1, x, y) - quadratic Bézier curve commands.

# utils.q(x1, y1, x, y)

# utils.T(x, y) - smooth quadratic Bézier curve commands.

# utils.t(x, y)

# utils.Z() - “closepath” commands.

# utils.z()

Todo: add .A(...) and .a(...) - elliptical arc curve commands.

Example of usage:

utils.M(50,100)            // return: "M50,100"
utils.L(200,300)           // return: "L200,300"
utils.c(10,20,30,40,50,60) // return: "c10,20 30,40 50,60"
utils.Z()                  // return: "Z" 

Path data utils

# utils.parse(d)

Parse path data d into sequence of operators ['M', 'L', ...] and sequence of principal points [(x,y)].

utils.parse("M50,100 L200,300 H100"); 
/* 
return: 
  { 
    operators: ["M", "L", "H"], 
    points: [
      {x: 50, y: 100}, 
      {x: 200, y: 300},  
      {x: 100}
    ]
  }
*/  

# utils.generate({ operators: [operators], points: [points]})

Generate path data d from a sequence of operators ['M', 'L', ...] and sequence of principal points [(x,y)].

const data = { 
  operators: ["M", "L", "H"], 
  points: [
    {x: 50, y: 100}, 
    {x: 200, y: 300},  
    {x: 100}
  ]
}
utils.generate(data); // return: "M50,100 L200,300 H100"

# utils.inversePath(d)

Calculate and return inverse path data for path data d.

utils.inversePath("M50,100 L200,300 Z"); // return: "M200,300 L50,100 Z"

# utils.join(args)

Join input args into a string with space (' ') separator.

utils.join("M50,100", "L200,300", "Z");                     // return: "M50,100 L200,300 Z"
utils.join(utils.M(50,100), utils.L(200,300), utils.Z());   // return: "M50,100 L200,300 Z"

Licence

MIT