C PNG Example program
---------------------

The example supplied is Willem van Schaik's PngMinus compiled directly from
the public released sources. It is expected that sources which use libpng
be simple to interwork with the PNG module veneers.

The suitability of this code for any particular purpose is not guarenteed.
This source is provided as an example of a freely available source which
can be made to function with the shared PNG library.


Building
--------

The file 'Makefile-norcroft' is for use with the Acorn C/C++ package.
The file 'Makefile-gcc' is for use with the RISC OS port of GCC.


Changes
-------

Only one change has been made to the code to allow it to build. The file
c.pnm2png, lines 514 and 515 refer to 'token', a png_byte array which was
being passed where a 'char *' is required and cannot be promoted. The code
explicitly casts the variable to a 'char *' to allow the code to compile.

