math

math — go-tex

A pure-Go (no cgo) TeX math-mode typesetter → SVG. It parses a subset of TeX math syntax and lays it out to a self-contained <svg> using the OpenType MATH table — via go-opentype for MATH metrics and vector glyph outlines — with no TeX engine, no server, and no cgo. It compiles to GOOS=js/GOARCH=wasm, so it renders math client-side and offline in a browser Web Worker.

This is the math-mode component of the go-tex pure-Go TeX effort; the full engine will live in go-tex/tex.

What it does

Typesets, using real OpenType MATH metrics (axis height, script shifts, fraction rule thickness, script scale-down, …):

• variables as Unicode math-italic, digits and operators upright;
• superscripts (^) and subscripts (_), including both on one nucleus;
• fractions (\frac{num}{den}) with the rule on the math axis;
• grouping ({…}) and nesting (fractions inside scripts inside fractions);
• a named-symbol table (\alpha, \sum, \int, \leq, \rightarrow, …).

x^2 + 1        E = mc^2        \frac{x^2+1}{\alpha-\beta}        \sum_{i=1}^{n} i^2

Each renders to a crisp, resolution-independent SVG of positioned glyph paths (and a <rect> rule for fractions).

Install

go get github.com/go-tex/math

Usage

package main

import (
	"fmt"

	texmath "github.com/go-tex/math"
)

func main() {
	// DefaultFont returns an embedded MATH font (STIX Two Math, OFL).
	r, err := texmath.New(texmath.DefaultFont())
	if err != nil {
		panic(err)
	}
	svg, err := r.RenderSVG(`\frac{x^2+1}{\alpha-\beta}`, 40) // 40px base size
	if err != nil {
		panic(err)
	}
	fmt.Println(svg) // <svg …>…</svg>
}

New accepts any OpenType font that carries a MATH table (STIX Two Math, Latin Modern Math, XITS Math, …); DefaultFont embeds STIX Two Math so the zero-config path — and the wasm worker — is self-contained.

WebAssembly

Being pure Go (CGO=0), it compiles to GOOS=js GOARCH=wasm. cmd/wasm is a worker that exposes globalThis.renderMathSVG(tex):

GOOS=js GOARCH=wasm go build -o texmath.wasm ./cmd/wasm

Measured (STIX Two Math embedded): ~1.6 MB gzip worker (most of it the font, which is subsettable), ~0.1–0.3 ms per formula — fast enough to re-render on every keystroke.

Scope

This is the math-mode core. Not yet implemented (planned): radicals (\sqrt as a built extensible radical rather than a symbol), big operators with display-style limits, extensible delimiters via the MATH variant/assembly tables, and the full TeX inter-atom spacing table. The named-symbol set is intentionally small and easy to extend.

Tests

Statement coverage is held at 100% (parser, layout, and error paths), go vet clean, and green across the six 64-bit Go targets plus js/wasm and wasip1/wasm.

go test ./...

Fonts

DefaultFont embeds STIX Two Math, licensed under the SIL Open Font License 1.1 — see STIXTwoMath-OFL.txt. The test-only testdata/nomath.otf is Source Serif 4 (also OFL).

License

BSD-3-Clause — see LICENSE. Copyright the go-tex/math authors. (The embedded font is under its own OFL license, above.)