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<html> <head><title>The Design of FreeType 2 - Introduction</title> <basefont face="Georgia, Arial, Helvetica, Geneva"> <style content="text/css"> P { text-align=justify } H1 { text-align=center } H2 { text-align=center } LI { text-align=justify } </style> </head> <body text=#000000 bgcolor=#ffffff> <center><table width="500"><tr><td> <center><h1>The Design of FreeType 2</h1></center> <table width="100%" cellpadding=5><tr bgcolor="#ccccee"><td> <h1>Introduction</h1> </td></tr></table> <p>This document provides details on the design and implementation of the FreeType 2 library. Its goal is to allow developers to better understand the way FT2 is organized, in order to let them extend, customize and debug it.</p> <p>Before anything else, it is important to understand the <em>purpose</em> of this library, i.e. why it has been written:</p> <ul> <li><p>first of all, to allow client applications to <em>access font files easily</em>, wherever they could be stored, and as independently of font format as possible.</p></li> <li><p>to allow easy <em>retrieval of global font data</em> most commonly found in normal font formats (i.e. global metrics, encoding/charmaps, etc..)</p></li> <li><p>to allow easy <em>retrieval of individual glyph data</em> (metrics, images, name, anything else)</p></li> <li><p>to allow <em>access to font format-specific "features"</em> whenever possible (e.g. SFNT tables, Multiple Masters, OpenType Layout tables, etc..)</p></li> </ul> <p>its design has also severely been influenced by the following requirements:</p> <ul> <li><p><b>high portability</b>, as the library must be able to run on any kind of environment. this requirement introduces a few drastic choices that are part of FreeType 2's low-level system interface.</p></li> <li><p><b>extendibility</b>, as new features should be added with the least modifications in the library's code base. this requirements induces an extremely simple design where nearly all operations are provided by modules. </p></li> <li><p><b>customization</b>, it should be easy to build a version of the library that only contains the features needed by a specific project. This really is important when you need to integrate it in a font server for embedded graphics libraries.</p></li> <li><p><b>compactness</b> and <b>efficiency</b>, given that the primary target for this library is embedded systems with low cpu and memory resources.</p></li> </ul> <p>The rest of this document is divided in several sections. First, a few chapters will present the library's basic design as well as the objects/data managed internally by FreeType 2.</p> <p>A later section is then dedicated to library customization, relating such topics as system-specific interfaces, how to write your own module and how to tailor library initialisation & compilation to your needs.</p> </td></tr></table></center> </body> </html>