---
title: hvf
framework: hvf
role: collection
role_heading: Framework
platforms: [iOS 18.4+, iPadOS 18.4+, Mac Catalyst 18.4+, macOS 15.4+, tvOS 18.4+, visionOS 2.4+, watchOS 11.4+]
path: hvf
---

# hvf

Render Hierarchical Variable Font (HVF) glyph outlines, and support font editors and related tools.

## Overview

Overview The hvf library provides C and Swift interfaces. The C interface supports rendering hvgl and hvpm tables in existing fonts. The Swift interface adds support for the following: Writing a custom loader to render HVF glyphs from other sources, such as a database in a font editor. Generating data needed to build an hvgl table, using the same code as the custom loader. Interactively modifying part appearances and data, such as in a font editor.

## Topics

### Classes

- [HVGLPartLoader](hvf/hvglpartloader.md)
- [PartRenderer](hvf/partrenderer.md)

### Protocols

- [CompositeWriter](hvf/compositewriter.md)
- [PartGenerator](hvf/partgenerator.md)
- [ShapeWriter](hvf/shapewriter.md)

### Structures

- [CompositeExtremumIndex](hvf/compositeextremumindex.md)
- [CompositeSubpart](hvf/compositesubpart.md)
- [CompositeSubpartTranslation](hvf/compositesubparttranslation.md)

### Variables

- [hvfLibraryVersion](hvf/hvflibraryversion-swift.var.md)

### Type Aliases

- [CustomPartLoader](hvf/custompartloader.md)

### Enumerations

- [AxisExtremum](hvf/axisextremum.md)
- [PartResult](hvf/partresult.md)
- [PointCoordinate](hvf/pointcoordinate.md)
- [SegmentBlendType](hvf/segmentblendtype.md)
- [SegmentPoint](hvf/segmentpoint.md)