Introduction

Apple Type Services for Unicode Imaging (ATSUI) enables the rendering of Unicode-encoded text with advanced typographic features. It automatically handles many of the complexities inherent in text layout, including how to correctly render text in bidirectional and vertical script systems.

This document describes the ATSUI application programming interface (API) through version 1.2 and may be useful to developers who are writing new text editors or word processing applications that renders Unicode-encoded text. You can also use the ATSUI API if you wish to modify your existing application to support Unicode text rendering.

If you are a font designer or want more information about fonts, see the Apple font group site:

http://fonts.apple.com/.

This document describes the ATSUI API in the following chapters:

ATSUI Reference describes the complete API through ATSUI 1.2, including functions, data types, constants, and result codes.
Document Revision History provides a history of revisions to this document.
History of API Additions and Changes in ATSUI provides a history of changes to the API since ATSUI 1.0.
Summary of Style Run and Text Layout Attribute Tag Information provides tabular summaries of the Apple-defined style run and text layout attribute tags and the data type, size, and default values of the attributes they identify.
New Constants and Data Types Used by ATSUI describes new constants and data types used by ATSUI from Unicode Utilities, the Script Manager, AAT Font Table Text Rendering Utilities, and AAT Font Table Text Layout Utilities.
Glossary provides an alphabetical listing of typographic and ATSUI-specific terms.