ref: 1ea9378ad3e250473464fde4ab336607a958eab1
parent: 4e4a43631c91cceeae2f90e190ca2cef67910374
author: Werner Lemberg <[email protected]>
date: Sat Oct 28 12:59:44 EDT 2000
Revised.
--- a/docs/ft2faq.html
+++ b/docs/ft2faq.html
@@ -1,13 +1,12 @@
+<!doctype html public "-//w3c//dtd html 4.0 transitional//en"
+ "http://www.w3.org/TR/REC-html40/loose.dtd">
<html>
<head>
-<title>FreeType 2 FAQ</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>
+ <meta http-equiv="Content-Type"
+ content="text/html; charset=iso-8859-1">
+ <meta name="Author"
+ content="David Turner">
+ <title>FreeType 2 FAQ</title>
</head>
<body text="#000000"
@@ -19,484 +18,580 @@
<font size=1>http://www.freetype.org</font><p>
-<center>
+<h1 align=center>
<a href="freetype.html">
- <img src="image/freetype.jpg" width=550 height=105 alt="The FreeType Project" border=0></a>
- <h1>The FreeType 2 FAQ</h1>
-</center>
+ <img src="image/freetype.jpg"
+ width=550 height=105
+ alt="The FreeType Project"
+ border=0></a>
+ <h1>The FreeType 2 FAQ</h1>
+</h1>
-<center><table width=750 cellspacing=10 cellpadding=30><tr><td>
-<hr><p>
+<center>
+<table width="75%">
+<tr><td>
-DOCUMENT INDEX:<br>
-<ul>
- <li><p><a href="#general">General</a>
- <ul>
- <li><a href="#general-dead">I thought the FreeType project was dead. It this true?</a></li>
- <li><a href="#general-long">Why did it take so long to release FreeType 2?</a></li>
- <li><a href="#general-unix">Is FreeType 2 a Unix-only project?</a></li>
- <li><a href="#general-x11">When will X11 support anti-aliased glyphs?</a></li>
- <li><a href="#general-ft1">Is FreeType 2 backwards compatible with 1.x?</a></li>
- <li><a href="#general-edit">Can I use FreeType 2 to edit fonts or create new ones?</a></li>
- </ul></p>
- </li>
- <li><p><a href="#builds">Compilation & Configuration</a>
- <ul>
- <li><a href="#builds-compile">How do I compile the FreeType 2 library?</a></li>
- <li><a href="#builds-config">How do I configure my library build?</a></li>
- <li><a href="#builds-modules">How do I select the modules I need?</a></li>
- <li><a href="#builds-flat">How do I compile all FreeType 2 files in a single directory?</a></li>
- </ul>
- </p></li>
- <li><p><a href="#library">Using the FreeType 2 library</a></p></li>
- <li><p><a href="#autohint">The FreeType 2 Autohinter</a>
- <ul>
- <li><a href="#autohint-license">Under which license is the auto-hinter released ?</a></li>
- <li><a href="#autohint-work">How does auto-hinting work in FreeType 2 ?</a></li>
- <li><a href="#autohint-cjk">Why doesn't the auto-hinter work well with CJK fonts ?</a></li>
- </ul>
- </p></li>
- <li><p><a href="#other">Other questions</a>
- <ul>
- <li><a href="#other-antialias">What is the anti-aliasing algorithm used in the FreeType 2 renderer?</a></li>
- <li><a href="#other-opentype">When will FreeType 2 support OpenType ?</a></li>
- </ul></p>
- </li>
-</ul><p>
+ <hr><p>
+ Document index
-<hr><p>
+ <ul>
+ <li><a href="#general">General</a>
+ <ul><p>
+ <li>
+ <a href="#general-dead">I thought the FreeType project was dead.
+ Is this true?</a>
+ </li>
+ <li>
+ <a href="#general-long">Why did it take so long to release
+ FreeType 2?</a>
+ </li>
+ <li>
+ <a href="#general-unix">Is FreeType 2 a Unix-only
+ project?</a>
+ </li>
+ <li>
+ <a href="#general-x11">When will X11 support anti-aliased
+ glyphs?</a>
+ </li>
+ <li>
+ <a href="#general-ft1">Is FreeType 2 backwards compatible
+ to FreeType 1.x?</a>
+ </li>
+ <li>
+ <a href="#general-edit">Can I use FreeType 2 to edit fonts
+ or create new ones?</a>
+ </li>
+ </p></ul>
+ </li>
+ <li><a href="#builds">Compilation & Configuration</a>
+ <ul><p>
+ <li>
+ <a href="#builds-compile">How do I compile the FreeType 2
+ library?</a>
+ </li>
+ <li>
+ <a href="#builds-config">How do I configure my library build?</a>
+ </li>
+ <li>
+ <a href="#builds-modules">How do I select the modules I need?</a>
+ </li>
+ <li>
+ <a href="#builds-flat">How do I compile all FreeType 2 files
+ in a single directory?</a>
+ </li>
+ </p></ul>
+ </li>
+ <li>
+ <a href="#autohint">The FreeType 2 autohinter</a>
+ <ul><p>
+ <li>
+ <a href="#autohint-license">Under which license is the auto-hinter
+ released?</a>
+ </li>
+ <li>
+ <a href="#autohint-work">How does auto-hinting work in
+ FreeType 2?</a>
+ </li>
+ <li>
+ <a href="#autohint-cjk">Why doesn't the auto-hinter work well
+ with CJK fonts?</a>
+ </li>
+ </p></ul>
+ </li>
+ <li>
+ <a href="#other">Other questions</a>
+ <ul><p>
+ <li>
+ <a href="#other-antialias">Which anti-aliasing algorithm is
+ used in the FreeType 2 renderer?</a>
+ </li>
+ <li>
+ <a href="#other-opentype">When will FreeType 2 support
+ OpenType?</a>
+ </li>
+ </p></ul>
+ </li>
+ </ul>
-<table width="100%" cellspacing=5><tr bgcolor="#CCCCEE"><td>
-<h2 align=center><a name="general">General questions & answers</h2>
-</td></tr><tr><td>
+ <p><hr></p>
-<a name="general-dead">
-<h3>I.1. I though the FreeType project was dead. Is this true?</h3>
-<ul>
- <p>Well, not exactly :-) It's true that the TrueType patents issues
- have been less than a graceful event to handle but it didn't not
- really killed the project per se, as Apple hasn't made an official
- statement yet regarding the use of the patented "technology" in
- open source projects (or other products).</p>
+ <table width="100%">
+ <tr bgcolor="#CCCCEE"><td>
+ <h2 align=center>
+ <a name="general">General questions & answers</h2>
+ </td></tr>
+ <tr><td>
- <p>We have thus continued updating FreeType 1.x, and started developping
- FreeType 2 with the idea of providing this time a completely patent
- free font engine. However, we largely preferred not to broadly
- communicate about it until we've got a satisfying implementation
- to show.</p>
-</ul>
+ <a name="general-dead">
+ <h3>
+ I.1 I though the FreeType project was dead. Is this true?
+ </h3>
+ <p>Well, not exactly :-) It's true that the TrueType patents
+ issues have been less than a graceful event to handle but it didn't not
+ really killed the project per se, as Apple hasn't made an official
+ statement yet regarding the use of the patented "technology" in open
+ source projects (or other products).</p>
-<a name="general-long">
-<h3>I.2. Why did it take so long to release FreeType 2?</h3>
-<ul>
- <p>Several factors come to mind. The first one is that FreeType 2 is
- a much more complex and dense project that was mostly developed
- on non-working hours. And surely some important changes in the
- life (like marriage, new jobs and kids) of some the FreeType
- developers cannot be ignored :-)</p>
+ <p>We have thus continued updating FreeType 1.x, and started
+ developing FreeType 2 with the idea of providing this time a
+ completely patent free font engine. However, we largely preferred not
+ to broadly communicate about it until we've got a satisfying
+ implementation to show.</p>
- <p>A second one is that a first version of the library was designed
- one year ago (and already worked with a multitude of font drivers),
- though with a design that was judged by its authors as well as
- beta testers as not enough flexible or consistent. In short, it worked
- well but we were not exactly proud of it (call us perfectionists).
- It has then be significantly reworked to become what we're now
- distributing as FreeType 2</p>
+ <a name="general-long">
+ <h3>
+ I.2 Why did it take so long to release FreeType 2?
+ </h3>
- <p>Finally, it would have been hard to distribute such a library without
- an alternative technology to replace the patented bytecode interpreter.
- This involved significant research work that could only be performed
- correctly full-time, and we had to found a company to fund such a
- development and still make it available under a BSD-like license.
- Huge thanks to <a href="http://www.catharon.com">Catharon Productions, Inc.</a>
- for their commitment to this project.</p>
+ <p>Several factors come to mind. The first one is that FreeType 2
+ is a much more complex and dense project that was mostly developed
+ during non-working hours. And surely some important changes in the life
+ (like marriage, new jobs and kids) of some the FreeType developers
+ cannot be ignored :-)</p>
- <p>And of course, we added support for more font files, and we'll
- continue to as long as the specs are available and that we find an
- interest in it. For example, FreeType 2 is to date the only
- software library available on the market that supports the new
- Adobe "CEF" font format.</p>
-</ul>
+ <p>A second one is that a first version of the library was designed one
+ year ago (and already worked with a multitude of font drivers), though
+ with a design that was judged by its authors as well as beta testers as
+ not enough flexible or consistent. In short, it worked well but we were
+ not exactly proud of it (call us perfectionists). It has then be
+ significantly reworked to become what we are now distributing as
+ FreeType 2</p>
-<a name="general-unix">
-<h3>I.3. Is FreeType 2 a Unix-only project?</h3>
-<ul>
- <p>Absolutely not, even though many people still seem to think so :-)
- FreeType 2, just like version 1.x, can be compiled on any platform with
- an ANSI compiler. Some beta versions of the library are even heavily
- used in brand new OSes (see the <a href="http://www.atheos.cx">AtheOS
- </a> screenshots for examples).</p>
+ <p>Finally, it would have been hard to distribute such a library without
+ an alternative technology to replace the patented bytecode interpreter.
+ This involved significant research work that could only be performed
+ correctly full-time, and we had to found a company to fund such a
+ development and still make it available under a BSD-like license. Huge
+ thanks to <a href="http://www.catharon.com">Catharon Productions,
+ Inc.</a> for their commitment to this project.</p>
- <p>The library is itself mainly developped on several platforms
- (Windows & Linux, though a great deal has also been achieved on OS/2)
- and the code is highly generic and modular to adapt even the most
- strict environments like low-memory embedded systems.</p>
+ <p>And of course, we added support for more font files, and we will
+ continue to as long as the specifications are available and that we find
+ an interest in it. For example, FreeType 2 is to date the only
+ software library available on the market that supports the new Adobe
+ "CEF" font format.</p>
-</ul>
+ <a name="general-unix">
+ <h3>
+ I.3 Is FreeType 2 a Unix-only project?
+ </h3>
-<a name="general-x11">
-<h3>I.4. When will X11/XFree support anti-aliased text?</h3>
-<ul>
- <p>This question isn't exactly related to FreeType as we have no direct
- connection to the XFree people, but we've been asked so frequently
- about it that it deserves a prominent place in this FAQ :-)</p>
+ <p>Absolutely not, even though many people still seem to think
+ so :-) FreeType 2, just like version 1.x, can be compiled
+ on any platform with an ANSI compiler. Some beta versions of the
+ library are even heavily used in brand new OSes (see the <a
+ href="http://www.atheos.cx">AtheOS</a> screenshots for examples).</p>
- <p>FreeType has been capable of anti-aliasing since version 1.0. The
- reason why XFree doesn't support it is directly related to the
- limitations of the design and specification of X11. More specifically:</p>
+ <p>The library is itself mainly developed on several platforms (Windows
+ & Linux, though a great deal has also been achieved on OS/2) and the
+ code is highly generic and modular to adapt even the most strict
+ environments like low-memory embedded systems.</p>
- <ul>
- <li><p>
- X11 assumes that all glyph images are monochrome bitmaps,
- hence the X font library and server are unable to send anything
- else to the X server.
- </p></li>
+ <a name="general-x11">
+ <h3>
+ I.4 When will X11/XFree support anti-aliased text?
+ </h3>
- <li><p>
- Even if the X font library/server was able to generate anti-aliased
- bitmaps (and this has been already done through extensions), the X
- rendering model doesn't allow translucent composition of "gray" pixmaps
- onto an arbitrary drawable.
- </p></li>
- </ul>
+ <p>This question isn't exactly related to FreeType as we have no direct
+ connection to the XFree people, but we have been asked so frequently
+ about it that it deserves a prominent place in this FAQ :-)</p>
- <p>As both the font and rendering models of X11 are limited, it's basically
- impossible to draw anti-aliased glyphs without performing <em>huge</em>
- hacks within the server.</p>
+ <p>FreeType has been capable of anti-aliasing since version 1.0.
+ The reason why XFree doesn't support it is directly related to the
+ limitations of the design and specification of X11. More
+ specifically:</p>
- <p>Note that Keith Packard, from XFree fame, has recently started working
- on a new rendering model for X11 in order to support new features
- (mainly transparency and anti-aliased fonts). This will be provided
- through protocol extensions. The question of knowing wether legacy X
- applications will be able to display anti-aliased text is still very
- uncertain.
- </p>
-</ul>
+ <ul>
+ <li>
+ X11 assumes that all glyph images are monochrome bitmaps, hence the
+ X font library and server are unable to send anything else to
+ the X server.
+ </li>
+ <li>
+ Even if the X font library/server was able to generate
+ anti-aliased bitmaps (and this has been already done through
+ extensions), the X rendering model doesn't allow translucent
+ composition of "gray" pixmaps onto an arbitrary drawable.
+ </li>
+ </ul>
-<a name="general-ft1">
-<h3>I.5. Is FreeType 2 backwards compatible with FreeType 1.x?</h3>
-<ul>
- <p>Not directly, though we had the project to provide an optional binary
- compatibility layer on top of it in order to easily re-link applications
- with the new version. However, this idea has been dropped as it is
- possible to install and use the two versions independtly on any
- system (read: no namespace conflicts).</p>
+ <p>As both the font and rendering models of X11 are limited, it is
+ basically impossible to draw anti-aliased glyphs without performing
+ <em>huge</em> hacks within the server.</p>
- <p>The FreeType 2 API is a lot simpler than the one in 1.x while being
- much more powerful. We thus encourage you to adapt your source code
- to it as this should not involve much work.</p>
+ <p>Note that Keith Packard, from XFree fame, has recently started
+ working on a new rendering model for X11 in order to support new
+ features (mainly transparency and anti-aliased fonts). This will be
+ provided through protocol extensions. The question of knowing whether
+ legacy X applications will be able to display anti-aliased text is still
+ very uncertain.</p>
-</ul>
+ <a name="general-ft1">
+ <h3>
+ I.5 Is FreeType 2 backwards compatible with FreeType 1.x?
+ </h3>
-<a name="general-edit">
-<h3>I.6. Can I use FreeType 2 to edit fonts or create new ones?</h3>
-<ul>
- <p>The answer is a definitive NO, because the library was specifically
- designed to <em>read</em> font files with small code size and very
- low memory usage.</p>
+ <p>Not directly, though we had the project to provide an optional binary
+ compatibility layer on top of it in order to easily re-link applications
+ with the new version. However, this idea has been dropped as it is
+ possible to install and use the two versions independently on any system
+ (read: no namespace conflicts).</p>
- <p>We thus do not plan to support editing or creation in the font
- engine in any way, as this would imply a complete rewrite. This
- doesn't mean that we won't introduce a font editing/creation library
- in the future, as this really depends on how many people are asking
- for it (or how much they would be willing to pay for it), as well as
- the time of the FreeType developers.</p>
+ <p>The FreeType 2 API is a lot simpler than the one in 1.x
+ while being much more powerful. We thus encourage you to adapt your
+ source code to it as this should not involve much work.</p>
- <p>Do not expect anything in this direction until we officially announce
- something though. There are other axis of development for this project
- (like text-layout capabilities, glyph caching, etc..) that may be more
- important to us at the moment..</p>
-</ul>
+ <a name="general-edit">
+ <h3>
+ I.6 Can I use FreeType 2 to edit fonts or create new ones?
+ </h3>
-</td></tr></table>
+ <p>The answer is a definitive <b>no</b>, because the library was
+ specifically designed to <em>read</em> font files with small code size
+ and very low memory usage.</p>
-<table width="100%" cellspacing=5><tr bgcolor="#CCCCEE"><td>
-<h2 align=center><a name="builds">Compilation & Configuration</h2>
-</td></tr><tr><td>
+ <p>We thus do not plan to support editing or creation in the font engine
+ in any way, as this would imply a complete rewrite. This doesn't mean
+ that we won't introduce a font editing/creation library in the future,
+ as this really depends on how many people are asking for it (or how much
+ they would be willing to pay for it), as well as the time of the
+ FreeType developers.</p>
-<a name="builds-compile">
-<h3>II.1. How do I compile the FreeType 2 library?</h3>
-<ul>
- <p>The library can be compiled in various ways, and a detailed documentation
- is available in the file "<tt>freetype2/docs/BUILD</tt>". However, we'll
- summarize the process to a few cases:</p>
+ <p>Do not expect anything in this direction until we officially announce
+ something though. There are other axes of development for this project
+ (like text-layout capabilities, glyph caching, etc.) that may be more
+ important to us at the moment.</p>
+ </td></tr>
+ </table>
- <h3>a. by using the command-line 2 build system</h3>
+ <br>
- <p>The engine comes with a sophisticated build system that is used
- to configure and compile a build of the library. You'll need
- <em>GNU Make</em> installed on your platform (NOTE: It will <b>not</b>
- work with other Make tools).</p>
+ <table width="100%">
+ <tr bgcolor="#CCCCEE"><td>
+ <h2 align=center>
+ <a name="builds">Compilation & Configuration
+ </h2>
+ </td></tr>
+ <tr><td>
- <p>Basically, you'll need to invoke <tt>make</tt> a first time in the
- top-level FreeType 2 directory in order to setup the build. This will
- detect your current platform and choose a configuration sub-makefile to
- drive the build. A specific compiler can be selected on some platforms
- by providing an additional target. For example, on Win32:</p>
+ <a name="builds-compile">
+ <h3>
+ II.1 How do I compile the FreeType 2 library?
+ </h3>
- <ul>
- <li><b><tt>make visualc</tt></b> will select the Visual C++ compiler</li>
- <li><b><tt>make lcc</tt></b> will select the Win32-lcc compiler</li>
- </ul>
+ <p>The library can be compiled in various ways, and a detailed
+ documentation is available in the file <tt>freetype2/docs/BUILD</tt>.
+ However, we will summarize the process to a few cases:</p>
- <p>Note that on Unix, the first time make is called, a configure script
- located in "<tt>freetype2/builds/unix</tt>" will be run in order to
- automatically detect the platform & compiler.</p>
+ <h4>
+ a. Using the command-line 2 build system
+ </h4>
- <p>A summary will be displayed showing the detected platform and compiler
- selected. You'll then be able to start the build by invoking <tt>make</tt>
- a second time. In case of problem, consult the <tt>BUILD</tt> document.</p>
+ <p>The engine comes with a sophisticated build system that is used to
+ configure and compile a build of the library. You will need <em>GNU
+ Make</em> installed on your platform (<b>Note:</b> It will
+ <em>not</em> work with other Make tools).</p>
+ <p>Basically, you will need to invoke <tt>make</tt> a first time in
+ the top-level FreeType 2 directory in order to set up the build.
+ This will detect your current platform and choose a configuration
+ sub-makefile to drive the build. A specific compiler can be selected
+ on some platforms by providing an additional target. For example, on
+ Win32:</p>
- <h3>b. by direct compilation</h3>
+ <ul>
+ <li>
+ <b><tt>make visualc</tt></b> will select the Visual C++
+ compiler
+ </li>
+ <li>
+ <b><tt>make lcc</tt></b> will select the Win32-lcc compiler
+ </li>
+ </ul>
- <p>You can also directly compile the library from the command line by
- using these simple rules:</p>
+ <p>Note that on Unix, when the first time make is called, a configure
+ script located in <tt>freetype2/builds/unix</tt> will be run in order
+ to automatically detect the platform & compiler.</p>
- <ul>
- <li><p>
- You should place the directories "<tt>freetype2/include</tt>" and
- "<tt>freetype2/src</tt>" in your include path in order to compile
- any component of the library. You can also add the system-specific
- build directory (i.e. "<tt>builds/<em>system</em>/</tt>") in the
- case where an alternate implementation of some of the components
- is available there (e.g. the memory-mapped i/o implementation
- on some Unix systems).
- </p></li>
+ <p>A summary will be displayed showing the detected platform and
+ compiler selected. You will then be able to start the build by
+ invoking <tt>make</tt> a second time. In case of problem, consult the
+ <tt>BUILD</tt> document.</p>
- <li><p>
- The components of the library are located in sub-directories of
- "<tt>src</tt>", for example: "<tt>src/base</tt>",
- "<tt>src/truetype</tt>", etc..
- </p></li>
+ <h4>
+ b. Direct compilation
+ </h4>
- <li><p>
- Each component is normally compiled through a single C file that
- "wraps" other sources in the component's directory. For example,
- your should compile the TrueType font driver by compiling the
- file "<tt>src/truetype/truetype.c</tt>". The list of C files to
- compile for a feature-complete build of the library is given in
- the <tt>BUILD</tt> document.
- </p></li>
- </ul>
+ <p>You can also directly compile the library from the command line by
+ using these simple rules:</p>
- <h3>c. in a graphical IDE</h3>
- <ul>
- <p>Well, the process is vastly similar to the one described in b.,
- except that you need to set the include paths, source code paths,
- etc.. in dialog boxes before running the compilation.
- </p>
- </ul>
+ <ul>
+ <li>
+ You should place the directories <tt>freetype2/include</tt> and
+ <tt>freetype2/src</tt> in your include path in order to compile
+ any component of the library. You can also add the
+ system-specific build directory (i.e.
+ <tt>builds/<em>system</em>/</tt>) in the case where an alternate
+ implementation of some of the components is available there (e.g.
+ the memory-mapped i/o implementation on some Unix systems).
+ </li>
+ <li>
+ The components of the library are located in sub-directories of
+ <tt>src</tt>, for example: <tt>src/base</tt>,
+ <tt>src/truetype</tt>, etc.
+ </li>
+ <li>
+ Each component is normally compiled through a single C file that
+ <em>wraps</em> other sources in the component's directory. For
+ example, you should build the TrueType font driver by compiling
+ the file <tt>src/truetype/truetype.c</tt>. The list of
+ C files to compile for a feature-complete build of the
+ library is given in the <tt>BUILD</tt> document.
+ </li>
+ </ul>
-</ul>
+ <h4>
+ c. Using a graphical IDE
+ </h4>
-<a name="builds-config">
-<h3>II.2. How do I configure my build of the library?</h3>
-<ul>
- <p>Each build of the library is configured through two header files
- located in "<tt>include/freetype/config</tt>":</p>
+ <p>Well, the process is vastly similar to the one described in b.,
+ except that you need to set the include paths, source code paths, etc.
+ in dialog boxes before running the compilation.</p>
- <ul>
- <li><p><b><tt>ftoption.h</tt></b><br>
- This file contains various configuration macros whose definition
- can be toggled on a per-build basis. Each macro is heavily
- commented in this file's comment, and we invite you to refer
- to it directly.</p></li>
+ <a name="builds-config">
+ <h3>
+ II.2 How do I configure my build of the library?
+ </h3>
- <li><p><b><tt>ftmodule.h</tt></b><br>
+ <p>Each build of the library is configured through two header files
+ located in <tt>include/freetype/config</tt>:</p>
+
+ <ul>
+ <li>
+ <tt>ftoption.h</tt>
+ <br>
+ This file contains various configuration macros whose definition can
+ be toggled on a per-build basis. Each macro is heavily commented in
+ this file's comment, and we invite you to refer to it directly.
+ </li>
+ <li>
+ <tt>ftmodule.h</tt>
+ <br>
This file contains the list of all the modules that are initially
- registered (added) when the function <b><tt>FT_Init_FreeType</tt></b>
- is called. See the next answer to know how to change it and
- why it may be important.</p></li>
- </ul>
+ registered (added) when the function <tt>FT_Init_FreeType()</tt> is
+ called. See the next answer to know how to change it and why it may
+ be important.
+ </li>
+ </ul>
- <p>Alternatively, some specific implementations of some FT2 components
- can be provided in a "<tt>builds/<em>system</em>/</tt>" directory
- (e.g. the Unix-specific <tt>ftsystem.c</tt> that uses memory-mapped
- file for i/o).</p>
-</ul>
+ <p>Alternatively, some specific implementations of some FreeType 2
+ components can be provided in a <tt>builds/<em>system</em>/</tt>
+ directory (e.g. the Unix-specific <tt>ftsystem.c</tt> that uses
+ memory-mapped file for i/o).</p>
-<a name="builds-modules">
-<h3>II.3. How do I select the modules I need in my build?</h3>
-<ul>
- <p>The function <tt><b>FT_Init_FreeType</b></tt> creates a new instance
- of the FT2 library and registers a set of "default" modules before
- returning to the calling application. Its default implementation
- is in the file "<tt>src/base/ftinit.c</tt>".</p>
+ <a name="builds-modules">
+ <h3>
+ II.3 How do I select the modules I need in my build?
+ </h3>
- <p>The list of default modules used by <tt>ftinit.c</tt> is located in
- the configuration file "<tt>include/freetype/config/ftmodule.h</tt>".
- It is normally automatically generated by the build system by
- invoking the "<tt><b>make modules</b></tt>" command in the top
- level FT2 directory (note: only works with GNU Make, you can
- edit the file by hand otherwise). It does so by parsing all
- sub-directories of "<tt>src</tt>" that contain a file named
- <tt>module.mk</tt>.</p>
+ <p>The function <tt>FT_Init_FreeType()</tt> creates a new instance of
+ the FreeType 2 library and registers a set of "default" modules
+ before returning to the calling application. Its default implementation
+ is in the file <tt>src/base/ftinit.c</tt>.</p>
- <p>Note that a specific port or project is free to provide its own
- implementation of <tt>ftinit.c</tt> in order to ensure a different
- initialisation sequence. For example, one could do something like:</p>
+ <p>The list of default modules used by <tt>ftinit.c</tt> is located in
+ the configuration file <tt>include/freetype/config/ftmodule.h</tt>.
+ Normally, it is automatically generated by the build system by invoking
+ the "<tt><b>make modules</b></tt>" command in the top level
+ FreeType 2 directory (Note: this only works with GNU Make; you can
+ edit the file by hand otherwise). It does so by parsing all
+ sub-directories of <tt>src</tt> that contain a file named
+ <tt>module.mk</tt>.</p>
- <ul>
- <li><p>compile each module as a shared library (DLL or .so) with
- a common "entry point" to retrieve a pointer to its
- module class (there is already some code that allows this
- when compiling each module).</p></li>
+ <p>Note that a specific port or project is free to provide its own
+ implementation of <tt>ftinit.c</tt> in order to ensure a different
+ initialization sequence. For example, one could do something like:</p>
- <li><p>place these modules in a directory like
- "<tt>/usr/lib/freetype2/modules/</tt>"</p></li>
+ <ul>
+ <li>
+ Compile each module as a shared library (DLL or <tt>.so</tt>) with a
+ common "entry point" to retrieve a pointer to its module class
+ (there is already some code that allows this when compiling each
+ module).
+ </li>
+ <li>
+ Place these modules in a directory like
+ <tt>/usr/lib/freetype2/modules/</tt>.
+ </li>
+ <li>
+ Provide an implementation of <tt>ftinit.c</tt> that would scan the
+ directory for valid modules.
+ </li>
+ </ul>
- <li><p>provide an implementation of <tt>ftinit.c</tt> that would
- scan the directory for valid modules.</p></li>
- </ul>
+ <p>This example only emphasizes the flexibility that is left to
+ developers when building the library.</p>
- <p>This example only emphasize the flexibility that is left to
- developers when building the library.</p>
+ <a name="builds-flat">
+ <h3>
+ II.4 How do I compile all FreeType 2 files in a single
+ directory?
+ </h3>
-</ul>
+ <p>Some projects may need, for the sake of simplicity or ease of
+ building, to compile the FreeType 2 library with all source files
+ copied to a single directory. This is possible.</p>
-<a name="builds-flat">
-<h3>II.4. How do I compile all FreeType 2 files in a single directory?</h3>
-<ul>
- <p>Some projects may need, for the sake of simplicity or ease of
- building, to compile the FT2 library with all source files
- copied to a single directory. This is possible.</p>
+ <p>To do so, you have to copy all source files located under
+ <tt>src</tt> to your own directory (you must retain the include files in
+ a distinct hierarchy though), then compile each of the FreeType 2
+ component with the macro <tt>FT_FLAT_COMPILE</tt>. This will change the
+ way <tt>#include</tt> works during the build.</p>
- <p>To do so, you'll need to copy all source files located under
- "<tt>src</tt>" to your own directory (you must retain the
- include files in a distinct hierarchy though), then compile
- each of the FreeType 2 component with the macro
- <tt><b>FT_FLAT_COMPILE</b></tt>. This will change the way
- <tt><b>#include</b></tt> works during the build.</p>
-</ul>
+ </td></tr>
+ </table>
-</td></tr></table>
+ <br>
-<table width="100%" cellspacing=5><tr bgcolor="#CCCCEE"><td>
-<h2 align=center><a name="library">Using the FreeType 2 library</h2>
-</td></tr><tr><td>
+ <table width="100%">
+ <tr bgcolor="#CCCCEE"><td>
+ <h2 align=center>
+ <a name="autohint">The FreeType 2 auto-hinter
+ </h2>
+ </td></tr>
+ <tr><td>
-</td></tr></table>
+ <a name="autohint-license">
+ <h3>
+ III.1 Under which license is the FreeType 2 auto-hinter released?
+ </h3>
-<table width="100%" cellspacing=5><tr bgcolor="#CCCCEE"><td>
-<h2 align=center><a name="autohint">The FreeType 2 auto-hinter</h2>
-</td></tr><tr><td>
+ <p>The auto-hinter was initially designed and implemented under contract
+ for <a href="http://www.catharon.com">Catharon Productions, Inc</a>
+ which gladly accepted to released it under an open-source license
+ compatible with the FreeType one.</p>
-<a name="autohint-license">
-<h3>IV.1. Under which license is the FreeType 2 auto-hinter released</h3>
-<ul>
- <p>The auto-hinter was initially designed and implemented under contract
- for <a href="http://www.catharon.com">Catharon Productions, Inc</a>
- which gladly accepted to released it under an open-source license
- compatible with the FreeType one.</p>
+ <p>This license can be found in
+ <tt>src/autohint/CatharonLicense.txt</tt> and requires that you cite
+ Catharon Productions in your documentation (just like you do with
+ FreeType) when using the auto-hinting module.</p>
- <p>This license can be found in "<tt>src/autohint/CatharonLicense.txt</tt>"
- and requires that you cite Catharon Productions in your documentation
- (just like you do with FreeType) when using the auto-hinting module.</p>
+ <p>Other than that, you still have the same freedom than with the good
+ old FreeType license. Enjoy!</p>
- <p>Other than that, you still have the same freedom than with the good old
- FreeType license. Enjoy !</p>
-</ul>
+ <a name="autohint-work">
+ <h3>
+ III.2 How does the auto-hinter work?
+ </h3>
-<a name="autohint-work">
-<h3>IV.2. How does the auto-hinter works ?</h3>
-<ul>
- <p>Well, a complete description would be difficult. Have a look at the
- dedicated <a href="autohinting/index.html">auto-hinter pages</a> on the FreeType
- site, as they describe most of its details with graphics and explanations.
- You could also look at the source code if you want to :-)</p>
+ <p>Well, a complete description would be difficult. Have a look at the
+ dedicated <a href="autohinting/index.html">auto-hinter pages</a> on the
+ FreeType site, as they describe most of its details with graphics and
+ explanations. You could also look at the source code if you want
+ to :-)</p>
- <p>To give a few details, the auto-hinter is used to perform grid-fitting
- on scalable font formats that use bezier outlines as their primary glyph
- image format (this means nearly all scalable font formats today). When
- a given font driver doesn't provide its own hinter, the auto-hinter is
- used by default. When a format-specific hinter is provided, it is still
- possible to use the auto-hinter using the
- <tt><b>FT_LOAD_FORCE_AUTOHINT</b></tt> bit flag when calling
- <tt>FT_Load_Glyph</tt>.</p>
+ <p>To give a few details, the auto-hinter is used to perform
+ grid-fitting on scalable font formats that use Bézier outlines as
+ their primary glyph image format (this means nearly all scalable font
+ formats today). If a given font driver doesn't provide its own hinter,
+ the auto-hinter is used by default. If a format-specific hinter is
+ provided, it is still possible to use the auto-hinter using the
+ <tt>FT_LOAD_FORCE_AUTOHINT</tt> bit flag when calling
+ <tt>FT_Load_Glyph()</tt>.</p>
- <p>The auto-hinter currently doesn't use external hints to do its job,
- as it automatically computes global metrics (when it "opens" a font
- for the first time) and glyph "hints" from their outline. Note that
- we plan the ability to specify external hints, given that it is based
- on a constraint system. That could be used to support native hints
- in Type 1/Type 2 fonts, for example.</p>
-</ul>
+ <p>The auto-hinter currently doesn't use external hints to do its job,
+ as it automatically computes global metrics (when it "opens" a font for
+ the first time) and glyph "hints" from their outline. Note that we plan
+ the ability to specify external hints, given that it is based on a
+ constraint system. That could be used to support native hints in
+ Type 1/Type 2 fonts, for example.</p>
-<a name="autohint-cjk">
-<h3>IV.3. Why does the auto-hinter doesn't work correctly with CJK fonts ?</h3>
-<ul>
- <p>The auto-hinter was first designed to manage and hint latin-based fonts,
- as they consist of most of the fonts available today. It doesn't hint
- asian fonts, as well as a few other complex scripts, because we didn't
- put enough research on the topic yet. Hinting CJK isn't really more
- difficult than latin, just different with a set of different constraints
- (basically, more distortion of glyphs is acceptable as long as certain
- features like triple-stem positions are respected more strictly..).</p>
+ <a name="autohint-cjk">
+ <h3>
+ III.3 Why does the auto-hinter doesn't work correctly with CJK
+ fonts?
+ </h3>
- <p>We thus plan to handle such a case rather rapidly.. Please be patient.</p>
-</ul>
+ <p>The auto-hinter was first designed to manage and hint Latin-based
+ fonts, as they consist of most of the fonts available today. It doesn't
+ hint Asian fonts, as well as a few other complex scripts, because we
+ didn't put enough research on the topic yet. Hinting CJK isn't really
+ more difficult than Latin, just different, with a set of different
+ constraints (basically, more distortion of glyphs is acceptable as long
+ as certain features like triple-stem positions are respected more
+ strictly).</p>
+ <p>We thus plan to handle such a case in the near future. Please be
+ patient.</p>
+ </td></tr>
+ </table>
-</td></tr></table>
+ <br>
-<table width="100%" cellspacing=5><tr bgcolor="#CCCCEE"><td>
-<h2 align=center><a name="other">Other questions</h2>
-</td></tr><tr><td>
+ <table width="100%">
+ <tr bgcolor="#CCCCEE"><td>
+ <h2 align=center>
+ <a name="other">Other questions
+ </h2>
+ </td></tr>
+ <tr><td>
-<a name="other-antialias">
-<h3>V.1. What is the anti-aliasing algorithm used by FreeType 2 ?</h3>
-<ul>
- <p>The algorithm has been specifically designed for FreeType. It is
- based on ideas that were originally found in the implementation
- of the <a href="http://www.levien.com/libart">libArt</a> graphics
- library to compute the <em>exact pixel coverage</em> of a vector
- image with absolutely now sub-sampling/filtering.
- </p>
+ <a name="other-antialias">
+ <h3>
+ IV.1 Which anti-aliasing algorithm is used by FreeType 2?</h3>
- <p>However, these two implementations are radically distinct and use
- vastly different models. The FreeType 2 renderer is optimized
- specifically for rendering small complex shapes, like glyphs, at
- very high speed while using very few memory; while libArt shines
- at general shape/polygon processing, especially large ones.</p>
+ <p>The algorithm has been specifically designed for FreeType. It is
+ based on ideas that were originally found in the implementation of the
+ <a href="http://www.levien.com/libart">libArt</a> graphics library to
+ compute the <em>exact pixel coverage</em> of a vector image with
+ absolutely no sub-sampling/filtering.</p>
- <p>The FT2 anti-aliasing renderer is indeed <em>faster</em> than the
- monochrome renderer for small character sizes (typically < 20 pixels).
- This is explained because the monochrome renderer must perform two
- passes on the outline in order to perform drop-out control according
- to the TrueType spec (we could drop this requirement later though).</p>
+ <p>However, these two implementations are radically distinct and use
+ vastly different models. The FreeType 2 renderer is optimized
+ specifically for rendering small complex shapes, like glyphs, at very
+ high speed while using very few memory; while libArt shines at general
+ shape/polygon processing, especially large ones.</p>
- <p>We'll try to document its design in a later document, though this is
- not a priority for now.</p>
-</ul>
+ <p>The FreeType 2 anti-aliasing renderer is indeed <em>faster</em>
+ than the monochrome renderer for small character sizes (typically
+ <20 pixels). The reason is that the monochrome renderer must
+ perform two passes on the outline in order to perform drop-out control
+ according to the TrueType specification (we could drop this requirement
+ later though).</p>
-<a name="other-opentype">
-<h3>V.2. When will FreeType 2 support OpenType ?</h3>
-<ul>
- <p>Well, the engine already reads OpenType/CFF files perfectly. What it
- doesn't do is handle "OpenType Layout" tables yet.</p>
+ <p>We will try to document its design in a later document, though this
+ is not a priority for now.</p>
+
+ <a name="other-opentype">
+ <h3>
+ IV.2 When will FreeType 2 support OpenType?
+ </h3>
+
+ <p>Well, the engine already reads OpenType/CFF files perfectly. What it
+ doesn't do is handle "OpenType Layout" tables yet.</p>
- <p>FreeType 1 comes with a set of extensions that are used to load
- and manage OpenType Layout tables. It even has a demonstration program
- named "<tt>ftstrtto</tt>" used to demonstrate its capabilities that
- runs pretty smooth.</p>
+ <p>FreeType 1 comes with a set of extensions that are used to load
+ and manage OpenType Layout tables. It even has a demonstration program
+ named "<tt>ftstrtto</tt>" to show its capabilities.</p>
- <p>For FreeType 2, we have decided that the layout operations provided
- through these tables is better placed in a specific text-layout library,
- (many people having asked for such a thing). This new engine would not
- depend on FT2 explicitely and will be developed as a separate project.
- We plan to announce it in a few weeks with all gory details,
- once the definitive 2.0 release of FreeType has been made.</p>
-</ul>
+ <p>For FreeType 2, we have decided that the layout operations
+ provided through these tables are better placed in a specific
+ text-layout library, (many people having asked for such a thing). This
+ new engine will not depend on FreeType2 explicitly and will be developed
+ as a separate project. We plan to announce it in a few weeks with all
+ gory details, once the definitive 2.0 release of FreeType has been
+ made.</p>
-</td></tr></table>
+ </td></tr>
+ </table>
-<hr>
-<p>
-<a href="index.html">Back to FreeType homepage</a><p>
+ <p><hr></p>
-</td></tr></table>
+ <a href="index.html">Back to FreeType homepage</a><p>
+
+</td></tr>
+</table>
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