ref: 9acb09e060259fc3fa6bd4313d4d06f488f940f8
dir: /docs/VERSION.DLL/
Due to our use of "libtool" to generate and install the FreeType 2 libraries
on Unix systems, as well as other historical events, it is generally very
difficult to know precisely which release of the font engine is installed
on a given system.
This file tries to explain why and to document ways to properly detect
FreeType on Unix.
I. Version & Release numbers:
For each new public release of FreeType 2, there are generally *three*
distinct "version" numbers to consider:
* the official FT2 release number, like 2.0.9, or 2.1.3
* the libtool (and Unix) specific version number, like "9.2.3". This
is what "freetype-config --version" will return
* the platform-specific shared object number, used for example when
the library is installed as "/usr/lib/libfreetype.so.6.3.2"
the platform-specific number is, unsurprisingly, platform-specific and varies
with the operating system you're using (several variants of Linux, FreeBSD,
Solaris, etc...). You should thus _never_ use it, even for simple tests.
the libtool-specific number does not equal the release number but is tied
to it.
the release number is available at *compile* time through the following
macros defined in FT_FREETYPE_H:
- FREETYPE_MAJOR : major release number
- FREETYPE_MINOR : minor release number
- FREETYPE_PATCH : patch release number
see below for some Autoconf fragment to
the release number is also available at *runtime* through the
"FT_Library_Version" API. Unfortunately, this one wasn't available or
working correctly before the 2.1.3 official release !!
II. Table:
the following is a simple table that gives, for each official release,
the corresponding libtool number, as well as the shared object number
found on _most_ systems, but not all of them:
release libtool so
-------------------------------------
2.1.4 9.3.3 6.3.3
2.1.3 9.2.3 6.3.2
2.1.2 9.1.3 6.3.1
2.1.1 ? ?
2.1.0 ? ?
2.0.9 ? ?
III. AutoConf Code Fragment:
Lars Clausen contributed the following Autoconf fragment to detect at
which version of FreeType is installed on your system. This one tests
for a version that is at least 2.0.9, you should change the last line to
check against other release numbers.
AC_MSG_CHECKING([for version of FreeType])
FREETYPE_INCLUDE=`freetype-config --cflags | cut -c3-`
FREETYPE_MAJOR=`grep '^#define FREETYPE_MAJOR' $FREETYPE_INCLUDE/freetype/freetype.h | cut -d' ' -f3`
FREETYPE_MINOR=`grep '^#define FREETYPE_MINOR' $FREETYPE_INCLUDE/freetype/freetype.h | cut -d' ' -f3`
FREETYPE_PATCH=`grep '^#define FREETYPE_PATCH' $FREETYPE_INCLUDE/freetype/freetype.h | cut -d' ' -f3`
FREETYPE_VERSION=`echo | awk "BEGIN { printf \"%d\", ($FREETYPE_MAJOR * 1000 + $FREETYPE_MINOR) * 1000 + $FREETYPE_PATCH;}"`
AC_MSG_RESULT([$FREETYPE_MAJOR.$FREETYPE_MINOR.$FREETYPE_PATCH])
if test "$FREETYPE_VERSION" -ge 2000009; then