| 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 9.0.3 ? |
| 2.1.0 8.0.2 ? |
| 2.0.9 9.0.3 ? |
| 2.0.8 8.0.2 ? |
| |
| the libtool numbers are a bit inconsistent due to the library's history: |
| |
| - 2.1.0 was created as a development branch from 2.0.8 |
| (hence the same libtool numbers) |
| |
| - 2.0.9 was a bug-fix release of the "stable" branch, we |
| apparently incorrectly increased its libtool number |
| |
| - 2.1.4 is still in the "development" branch, however it's stable enough |
| to be the basis of an upcoming 2.2.0 release |
| |
| |
| |
| 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 |
| |