For 99% of the users this library will work directly with a recent
installation of PHP without any problem.
Experience shows that most of the trouble are caused by either an
old buggy version of the free-type TTF library or using an old
antiquated version of the GD library. In order to narrow it down the
problem the following steps is helpful.
- If no background images are displayed (instead a solid black box
are displayed) chances are that GD 2.x is available but the
jpg-config.inc.php has been changed so that true color images are
disabled. Correct this by enabling the USE_TRUECOLOR define.
- If background images does not work make sure the settings of
USE_GD2_LIBRARY corresponds to the actual installation, i.e. If the GD2
library is not available then this define must be false!
- If you are running IIS and Win2k and get the error "Can't find
font" when trying to use TTF fonts then try to change the paths to UNIX
style, i.e. "/usr/local/fonts/ttf/". Remember that the path is absolute
and not relative to the htdocs catalogue.
- If no images and no error messages gets sent back to the browser
then there is a big chance that HTTP-Server PHP module (e.g.
Apache-PHP) has crashed. This is often due to a broken PHP installation
and more than often a problem with the True Type libraries. The best
way to track these types of problem down is to investigate the
HTTP-Server logs or the general system logs for evidence of a PHP
crash. The other reasons is that in some rare cases the auto detection
of the GD library could fail. If only the GD1 library is available and
the JpGraph library mistakenly detects the GD2 this could in rare cases
cause PHP to crash. Please try re-run the example by setting the DEFINE
USE_GD2_LIBRARY to "false".
- If the system is running IIS on Windows and some images which uses
TTF fonts just return an empty page then try to set the TTF_DIR path
manually (in jpg-config.php) to the directory where all the TTF fonts
are stored (normally c:/WINDOWS/fonts)
- If the cache is enabled please make sure that the permissions are
correctly set for the cache directory so that the process running
Apache/PHP has write access to the cache directory.
- If the TTF fonts only shows up as yellow then you have a buggy
installation of the freetype font library and the only thing to do is
to re-install and setup PHP+GD again.