@vectojs/tex

@vectojs/tex is the Zero-DOM TeX math typesetting engine of the VectoJS graph: a vendored KaTeX parse/layout kernel, mechanically stripped of MathML and DOM emission, plus a self-contained SVG emit layer. It is a leaf package with no dependencies and exists for one constraint: canvas rasterization goes data URI -> Image -> createImageBitmap -> drawImage, so the output must carry its own glyph outlines and reference no external font or CSS — neither KaTeX's HTML/CSS output nor any webfont approach can survive that pipeline. @vectojs/markdown loads it on demand to typeset $...$, $$...$$, and ```math formulas.

Install

bun add @vectojs/tex

Usage

import { emitSVG, layout } from '@vectojs/tex';

// Parse + lay out TeX into a box tree (strictness violations never throw).
const tree = layout('x^2 + y^2 = z^2', { displayMode: true });

// Emit a self-contained SVG string plus its em-unit metrics.
const { svg, width, height, depth } = emitSVG(tree, { emPx: 16, color: '#e2e8f0' });

console.log(svg.slice(0, 80), width, height, depth);
// svg is a complete <svg> document with glyph paths inline — rasterizable
// through a data URI, safe to hand to an offscreen drawImage.

Highlights

• Vendored KaTeX kernel (src/kernel/, MIT): copied from a pinned commit by scripts/vendor-katex.ts and token-level stripped of MathML/DOM emission so it stays diffable against upstream; only the registry files are hand-written.
• Self-contained SVG emit (emitSVG): returns { svg, width, height, depth } in em units with every glyph outline inlined — no webfonts, no external references, inherits nothing from page CSS.
• Tolerant layout: layout(tex, { displayMode?, maxSize?, minRuleThickness?, maxExpand? }) renders questionable input instead of throwing for strictness violations, matching how a live editor needs typesetting to behave.
• Bounded glyph corpus: fonts resolve through resolveFont / shippedFonts, coverage is queryable via shippedGlyphCount() and getGlyph, and sizing scales through KATEX_FONT_SCALE and sizingRatio.
• Consumer-facing lazy load lives in @vectojs/markdown: the engine imports dynamically on the first formula (with preloadMathJax() / isMathJaxReady() controls), keeping prose-only bundles at their no-math floor.

Documents @vectojs/[email protected].

Documentation

• Markdown & math rendering
• Code blocks