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diff --git a/modules/freetype2/docs/CUSTOMIZE b/modules/freetype2/docs/CUSTOMIZE new file mode 100644 index 000000000..e8817b72b --- /dev/null +++ b/modules/freetype2/docs/CUSTOMIZE @@ -0,0 +1,152 @@ +How to customize the compilation of the library +=============================================== + + FreeType is highly customizable to fit various needs, and this + document describes how it is possible to select options and + components at compilation time. + + +I. Configuration macros + + The file `include/freetype/config/ftoption.h' contains a list of + commented configuration macros that can be toggled by developers to + indicate which features should be active while building the library. + + These options range from debug level to availability of certain + features, like native TrueType hinting through a bytecode + interpreter. + + We invite you to read this file for more information. You can + change the file's content to suit your needs, or override it with + one of the techniques described below. + + +II. Modules list + + If you use GNU make please edit the top-level file `modules.cfg'. + It contains a list of available FreeType modules and extensions to + be compiled. Change it to suit your own preferences. Be aware that + certain modules depend on others, as described in the file. GNU + make uses `modules.cfg' to generate `ftmodule.h' (in the object + directory). + + If you build FreeType in a directory separate from the source files, + put your customized `modules.cfg' in that directory; that way you + can keep the source files `clean'. + + If you don't use GNU make you have to manually edit the file + `include/freetype/config/ftmodule.h' (which is *not* used with if + compiled with GNU make) to add or remove the drivers and components + you want to compile into the library. See `INSTALL.ANY' for more + information. + + +III. System interface + + FreeType's default interface to the system (i.e., the parts that + deal with memory management and i/o streams) is located in + `src/base/ftsystem.c'. + + The current implementation uses standard C library calls to manage + memory and to read font files. It is however possible to write + custom implementations to suit specific systems. + + To tell the GNU Make-based build system to use a custom system + interface, you have to define the environment variable FTSYS_SRC to + point to the relevant implementation: + + on Unix: + + ./configure <your options> + export FTSYS_SRC=foo/my_ftsystem.c + make + make install + + on Windows: + + make setup <compiler> + set FTSYS_SRC=foo/my_ftsystem.c + make + + +IV. Overriding default configuration and module headers + + It is possible to override the default configuration and module + headers without changing the original files. There are three ways + to do that: + + + 1. With GNU make + + [This is actually a combination of method 2 and 3.] + + Just put your custom `ftoption.h' file into the objects directory + (normally `<topdir>/objs' if you build in the source tree, or the + directory where you invoke configure if you build in a separate + directory), which GNU make prefers over the standard location. No + action is needed for `ftmodule.h' because it is generated + automatically in the objects directory. + + 2. Using the C include path + + Use the C include path to ensure that your own versions of the + files are used at compile time when the lines + + #include FT_CONFIG_OPTIONS_H + #include FT_CONFIG_MODULES_H + + are compiled. Their default values being + <freetype/config/ftoption.h> and <freetype/config/ftmodule.h>, you + can do something like: + + custom/ + config/ + ftoption.h => custom options header + ftmodule.h => custom modules list + + include/ => normal FreeType 2 include + ... + + then change the C include path to always give the path to `custom' + before the FreeType 2 `include'. + + + 3. Redefining FT_CONFIG_OPTIONS_H and FT_CONFIG_MODULES_H + + Another way to do the same thing is to redefine the macros used to + name the configuration headers. To do so, you need a custom + `ft2build.h' whose content can be as simple as: + + #ifndef FT2_BUILD_MY_PLATFORM_H_ + #define FT2_BUILD_MY_PLATFORM_H_ + + #define FT_CONFIG_OPTIONS_H <custom/my-ftoption.h> + #define FT_CONFIG_MODULES_H <custom/my-ftmodule.h> + + #include <freetype/config/ftheader.h> + + #endif /* FT2_BUILD_MY_PLATFORM_H_ */ + + Place those files in a separate directory, e.g., + + custom/ + ft2build.h => custom version described above + my-ftoption.h => custom options header + my-ftmodule.h => custom modules list header + + and change the C include path to ensure that `custom' is always + placed before the FT2 `include' during compilation. + +---------------------------------------------------------------------- + +Copyright 2003-2016 by +David Turner, Robert Wilhelm, and Werner Lemberg. + +This file is part of the FreeType project, and may only be used, +modified, and distributed under the terms of the FreeType project +license, LICENSE.TXT. By continuing to use, modify, or distribute +this file you indicate that you have read the license and understand +and accept it fully. + + +--- end of CUSTOMIZE --- |