@mathlabs/voltik

CircuiTikZ circuits to SVG and PNG, without a TeX install: no LaTeX, no fonts on the system, no external processes. voltik is a library of tikra, which draws the TikZ; voltik adds the CircuiTikZ components, and labels are set by mathra in Latin Modern, TeX's own Computer Modern.

npm install @mathlabs/voltik

What it draws

Path-style components placed with to[…]: short, open, generic, resistors (R, American and European), capacitors (C) and inductors (L); labels and annotations (l, l_, a, R=label), straight, rotated or smart, with the siunitx shorthand 20<\ohm>; poles o and *; mirror and invert; \ctikzset and the class keys. The specification is the CircuiTikZ manual; what is drawn and what is not yet is in spec/subset.md. Every image below is an SVG written by voltik.

Node

Works right away:

import { circuitikzToSvg, render, png } from "@mathlabs/voltik";      // or: const { circuitikzToSvg } = require("@mathlabs/voltik")
import { writeFileSync } from "node:fs";

const svg = circuitikzToSvg(String.raw`\begin{circuitikz}\draw (0,0) to[R=$R_1$, o-*] (2,0);\end{circuitikz}`);
writeFileSync("r.svg", svg);
writeFileSync("r.png", png(svg, { dpi: 300 }));
const { warnings, alt } = render(String.raw`\begin{circuitikz}\draw (0,0) to[C] (2,0);\end{circuitikz}`);

Browsers and bundlers (Vite, webpack, esbuild)

Await init() once; it fetches voltik.wasm next to the module:

import { init, circuitikzToSvg } from "@mathlabs/voltik";

await init();
document.querySelector("#circuit").innerHTML = circuitikzToSvg(String.raw`\begin{circuitikz}\draw (0,0) to[L=$L$] (2,0);\end{circuitikz}`);

Without a bundler, from a CDN:

<script type="module">
  import { init, circuitikzToSvg } from "https://cdn.jsdelivr.net/npm/@mathlabs/voltik/web/index.js";
  await init();
  document.body.innerHTML = circuitikzToSvg(String.raw`\begin{circuitikz}\draw (0,0) to[R] (2,0);\end{circuitikz}`);
</script>

API

| | | |---|---| | init(input?) | Loads the wasm. Needed once in browsers and bundlers; does nothing in Node. input overrides where the wasm comes from (a URL, a Response, bytes or a WebAssembly.Module). | | circuitikzToSvg(code, options?) | The SVG as a string. options.locale ("en" by default, or "pt-BR", "es", "fr", "de", "it", "ru", "zh", "ja", "ko", "hi", "ar", "id", "tr", "nl", "pl") is the language of the figure in words; the drawing is the same in all. | | render(code, options?) | { svg, alt, description, warnings }: alt is the figure in one sentence (the SVG's <title>), description the figure in words (the SVG's <desc>), and warnings lists, as strings, what was ignored or approximated. The words are written by tikra from what it drew: review them before publishing. | | png(svg, options?) | PNG bytes as a Uint8Array. Options: dpi (300 by default) and background (true, white, by default; false for transparent). | | version() | The version of voltik's core inside the package (the npm package has its own version). |

code is a circuitikz environment, a tikzpicture that uses CircuiTikZ components, a full standalone document or loose statements. Errors (no figure in the input, an invalid dpi, a PNG past 100 megapixels) are thrown as Error.

Warnings, not errors

What voltik does not draw yet becomes a warning, and the rest of the circuit is drawn: a component it does not know (a source, a diode), an option it does not read.

Also for Python, Rust and the terminal

The same core is a Python module, a Rust crate and a command-line tool, and every one gives the same SVG, byte for byte. How to install each: github.com/matheusmota-dev-br/voltik.

License

The code is MIT or Apache-2.0; the fonts embedded through mathra are Latin Modern Math, under the GUST Font License, and STIX Two Math, under the SIL Open Font License 1.1.