Fixed an overflow bug in png.c where reading images with a palette or

[imager.git] / README

================================================================
Copyright (c) 1999, 2000 Arnar M. Hrafnkelsson. All rights reserved.
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
================================================================

>> THIS SOFTWARE COMES WITH ABSOLUTELY NO WARRANTY WHATSOEVER <<

================================================================


========================
1. Patent infringements?
========================

Imager as such contains no patented algorithms.  The external
libraries (which are not written by me) may or may not contain
patented algorithms.  YOU ARE SOLELY RESPONSIBLE FOR OBTAINING
LICENSE(S) TO USE SUCH LIBRARIES SHOULD YOU NEED ANY.


========================
2. Compiling and testing
========================

Some care has been taken to make the installation as smooth as
possible.  This is rather hard due to the difference between operating
systems and site setups.  To get started just type

$ perl Makefile.PL

It should blurb out a list of which libraries were found and which
not.  If you add a library to the machine after installing Imager it
does not automatically become available in Imager.  It only uses the
libraries that are found.  If the list of found libraries is not what
you expected, then the Makefile.PL is either not searching in the
right directories or your box does not have the libraries you think it
does.  For a list of where to get the libraries have a look at
3. External dependencies.  To widen the search path for libraries and
include files set the IM_INCPATH and IM_LIBPATH variables.  The
environment variables that matter when Makefile.PL is run are

IM_INCPATH      colon separated list of paths to extra include files
IM_LIBPATH      colon separated list of paths to extra library files

IM_VERBOSE      turns on verbose mode for the library scanning and such
IM_MANUAL       to manually select which libraries are used and which not
IM_NOLOG        if true logging will not be compiled into the module
IM_DEBUG_MALLOC if true malloc debugging will be compiled into the module
                do not use IM_DEBUG_MALLOC in production - this slows
                everything down

IM_CFLAGS       Extra flags to pass to the compiler
IM_LFLAGS       Extra flags to pass to the linker
IM_DFLAGS       Extra flags to pass to the preprocessor



When finding the libraries has been sorted out it's time for

$ make 

and if that works then do

$ make test

If either fails do take a peek at the file errep.perl.  It's creates a
file report.txt.  This is some information which will help me discover
where the problem is so I can try to fix it in future releases.  If
you find running it ok (just remember - no warranty!) please send the
report.txt via email to addi@umich.edu .

Troubleshooting tips:

A common problem is that libgif/libungif are sometimes linked to the X
libraries and then running the tests fails.  In that case something
like:

$ IM_LFLAGS="-L/usr/X11R6/lib -lX11" perl Makefile.PL

Which simply sets the environment variables for the extra libraries 
to include the X libraries (which we do not use at all, but must
included since libgif has been linked with it).

Also note that libgif has a few bugs: You can run something like

$ perl -Iblib/lib -Iblib/arch t/t10formats.t

This way you can see what comments the test script prints out.
t/t10formats.t checks for an bug in libgiff and prints out a patch
if that bug is present, note that this bug only affects the more
"advanced" features of libgif.

Imager needs to have a fairly recent libtiff installed (we know it
it runs fine with 3.5.5).  In the future we might consider supporting older
libtiff versions.  For now you can either configure Imager manually (by
setting the IM_MANUAL environment variable to 1, in sh:

$ IM_MANUAL=1 perl Makefile.PL

and simply say no to tiff support when asked if you want it, the same thing
can be used to circumvent problems in gifs to get Imager going.


If it worked just continue with the installation as normally 
(with make install).

========================
3. External dependencies
========================

Some hints about getting the Imager module to find the libraries it
needs for specific features.  The libraries it uses are:

 jpeg: ftp://ftp.uu.net/graphics/jpeg/jpegsrc.v6b.tar.gz

  png: ftp://ftp.uu.net/graphics/png  
  you also need zlib to use png:  ftp://ftp.uu.net/pub/archiving/zip/zlib

  gif: http://www.arrakeen.demon.co.uk/giflib/  
or at: http://prtr-13.ucsc.edu/~badger/software/libungif/index.shtml

 tiff: http://www.libtiff.org/

   t1: ftp://ftp.neuroinformatik.ruhr-uni-bochum.de/pub/software/t1lib/
or at: ftp://sunsite.unc.edu/pub/Linux/libs/graphics/

   tt: http://www.freetype.org/


Precompiled versions of some of the libraries might be found at:

AIX:
   http://www.bull.de/
   ftp://ftp.rge.com/pub/systems/aix/bull/



========================
4. Logging and debugging
========================

Logging is compiled in by default - if you should want to get of it
from the binaries you can do so by setting the env IMAGER_NOLOG 
to something. If you want to enable malloc debugging to check for leaks
then set IMAGER_DEBUG_MALLOC to something.  Needless to say it is
pretty pointless to have malloc debug enabled with no logging since you 
can never see the malloc information that way.


========================
5. Truetype information
========================

If you enable the truetype part and want it to be TESTED you MUST set
the environment variable TTFONTTEST to a complete path to a truetype
font.


=================
6. Win32 Support
=================

Imager can be installed on Win32 systems.  This was ported and tested
with Microsoft Visual C++ 6.0 with build 623 of ActivePerl.  If you
have the appropriate libraries installed you can read and write PNG,
TIFF, PPM and JPEG files.  There is currently no support for fonts
under Win32, though it might be preferable to try to use Win32's
native font support over the external librarie - why force the user to
install yet another library?

I haven't tried to target compilers other than VC++, since I don't
have them installed.

If you have any problems with the Win32 support, please email
tony@develop-help.com (don't forget to use nmake instead of make).

=======================
7. General information
=======================

The Imager module homepage is currently at:

 http://www.eecs.umich.edu/~addi/perl/Imager/

The current docs are rather bad as I've been busy adding features
but hopefully they will be updated soon.  Until then you'll just
have to use the source. The test scripts might also be a good idea.
By activating the the #init_log lines in the test script you can get
rather verbose debugging output from the C code.


========================
8. Thanks
========================

Thanks go to:
  Tony Cook           ( TonyC )
  Claes Jacobson      ( Claes )
  Philip Gwyn         ( Leolo )
  Brad Murray         ( HalfJack )
  Nicholas Dronen     ( Veblen )
  Michael G Schwern   ( Schwern )
  Rocco Caputo        ( Dngor )
  Graham barr         ( Gbarr )
  Mark-Jason Dominus  ( Mjd )
  Jerome
  Jason Alexander     ( Jalex )
  Randal R. Schwartz  ( Merlyn )
  Tkil                ( )
  Artur Bergman       ( Sky )
  Luc St-Louis        ( Lucs )
  PerlJam             ( )
  Roderick Schertler  ( Roderick )
  Nathan Torkington   ( gnat )

(and just to play it safe) all those I forgot to mention.