---
title: diyamantina/mathtypeset
framework: Swift Package Catalog
role: article
path: packages/diyamantina/mathtypeset
---

# diyamantina/mathtypeset

A small, dependency-free Swift package that typesets a TeX-math subset into a

## Install

```swift .package(url: "https://codeberg.org/MarkdownPdfHQ/MathTypeset.git", from: "0.7.0"), ```

```swift .target(name: "YourTarget", dependencies: ["MathTypeset"]), ```

## Usage

```swift import MathTypeset

// 1. Parse a formula. let parsed = try MathParser().parse(#"\frac{-b \pm \sqrt{b^2 - 4ac}}{2a}"#)

// 2. Build metrics from the font's OpenType MATH table. let table = try TrueTypeMathTableParser(bytes: mathTableBytes, numGlyphs: numGlyphs).parse() let metrics = MathLayoutMetrics.openType(constants: table.constants, unitsPerEm: unitsPerEm)

// 3. Lay it out. `measureText` is your font measurement (see the contract). let layout = MathLayout(     font: .regular,     color: .black,     measureText: { run in myAdvanceWidth(of: run.text, at: run.size) },     metrics: metrics, ) let box = try layout.layout(parsed.root, size: 11, displayStyle: true)

// 4. Emit. Walk box.elements and draw each in your backend. for element in box.elements {     switch element {     case let .text(run, x, y):         draw(run.text, at: (x, y), size: run.size, color: run.color)     case let .rule(x, y, width, height, color):         fillRect(x: x, y: y, width: width, height: height, color: color)     } } ```

## The measurement contract

This is load-bearing. The layout never measures glyphs itself; it calls your `measureText` closure and trusts the result. For the layout and the MATH-table metrics to agree:

- `measureText(run)` returns the **advance width of `run.text`, set in `run.font`   at `run.size`, in typographic points** (the same space `run.size` is in). - `MathLayoutMetrics.openType(constants:unitsPerEm:)` must be given the   `unitsPerEm` of the **same font** you measure against, so the MATH constants   (font units) normalize to the same point space your advances use. - The resulting `MathBox` (`width`, `height`, `depth`) and every element   coordinate are in **points at the formula's base size**. Emit at those   coordinates directly; do not rescale.

If you measure with one font but pass another font's `unitsPerEm`, or measure in a different unit than `run.size`, advances and metrics will disagree and the output will drift. Measure and feed metrics from one font artifact.

`baselineOffset` on a `MathRun` shifts that run vertically from the run's baseline (used for scripts). `MathBox.depth` is the extent below the baseline, useful for baseline-aligning inline math.

## Public surface

- `MathParser().parse(_:) -> MathParser.ParsedFormula` (`.root: MathNode`) - `MathNode` (the AST) - `MathLayout(font:color:measureText:metrics:).layout(_:size:displayStyle:) -> MathBox` - `MathBox`, `MathLayoutElement` (`.text(run:x:y:)` / `.rule(...)`) - `MathRun`, `MathFontStyle`, `MathColor` - `MathLayoutMetrics.openType(constants:unitsPerEm:)` and `.default` - `TrueTypeMathTableParser(bytes:numGlyphs:).parse() -> TrueTypeMathTable`   (`.constants`)

## License

MathTypeset is dual licensed as [AGPL-3.0](LICENSE) / commercial.

The AGPL is a free, open-source license, but that does not mean the software is free of obligations. It is a copyleft license: any derivative work, including software or a network service that incorporates MathTypeset, must also be released under the AGPL-3.0 with its complete corresponding source. If you are building something that cannot comply with the AGPL terms, a [commercial license](COMMERCIAL.md) is available that exempts you from them.

See [COMMERCIAL.md](COMMERCIAL.md) for commercial licensing.

## Package Metadata

Repository: diyamantina/mathtypeset

Default branch: main

README: README.md