# FreeType Glyph Conventions

## Version 2.1

### Copyright 1998-2000 David Turner (david@freetype.org)
Copyright 2000 The FreeType Development Team (devel@freetype.org)

This document presents the core conventions used within the FreeType library to manage font and glyph data. It is a must-read for all developers who need to understand digital typography, especially if you want to use the FreeType 2 library in your projects.

## Table of Contents

## I. Basic Typographic Concepts

> ### 1. Font files, format and information
> 2. Character images and mappings
> 3. Character and font metrics

## II. Glyph outlines

> ### 1. Pixels, points and device resolutions
> 2. Vectorial representation
> 3. Hinting and bitmap rendering

## III. Glyph metrics

> ### 1. Baseline, pens and layouts
> 2. Typographic metrics and bounding boxes
> 3. Bearings and advances
> 4. The effects of grid-fitting
> 5. Text widths and bounding box

## IV. Kerning

> ### 1. Kerning pairs
> 2. Applying kerning

## V. Text processing

> ### 1. Writing simple text strings
> 2. Sub-pixel positioning
> 3. Simple kerning
> 4. Right-to-left layouts
> 5. Vertical layouts
> 6. WYSIWYG text layouts

## VI. FreeType Outlines

> ### 1. FreeType outline description and structure
> 2. Bounding and control box computations
> 3. Coordinates, scaling, and grid-fitting

## VII. FreeType bitmaps

> ### 1. Vectorial versus pixel coordinates
> 2. FreeType bitmap and pixmap descriptor
> 3. Converting outlines into bitmaps and pixmaps