links and tests against zlib with a prefix; tests have been clarified; and
irrelevant or obsolete things (as defined by the autotools man page) have
been removed.
png_malloc_default png_free_default.
Updated some left over "1.6.0beta32" in code sources.
Fixed a "png_structp" prototype (should be png_structrp) in arm_init.c
Updated the version-number hack in pngvalid.c
handling png_struct members rearranged - partly to reorder to avoid packing,
partly to put frequently accessed members at the start and partly to make
the grouping more clear. png_set_filter code has been rewritten and the
code shared with png_write_start_row moved to a common function. Comments
in png.h have been made more clear. Minor fixes to
contrib/libtests/timepng.c and some of the png_*_tRNS logic, including
more error detection in png_set_tRNS.
READ_GAMMA. Prior to 1.6.0 switching off READ_GAMMA did unpredictable things
to the interfaces that use it (specifically, png_do_background in 1.4 would
simply display composite for grayscale images but do composition
with the incorrect arithmetic for color ones). In 1.6 the semantic
of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that
depends on it; this obliges people who set it to consider whether they
really want it off if they happen to use any of the interfaces in
question (typically most users who disable it won't).
management system (CMS). In practice it is not possible to obtain cHRM
information reliably using just the end-point tags because they do not exist
in the vast majority of profiles. Instead it is necessary to run the endpoints
through the ICC colorimetric intent transform (as described in the v4
spec). Since this is likely to be too much code inside libpng for too
little gain (it implies a fairly complete CMS implementation) the code
has been changed to allow an external CMS to be used. This code is
temporarily disabled until a suitable set of test cases using one or more
external CMS implementations have been implemented.
fixed Cygwin+MSVC build errors. The ICC profile handling now includes more
checking. Several errors that caused rejection of the profile are now
handled with a warning in such a way that the invalid profiles will be
read by default in release (but not pre-RC) builds but will not be
written by default. The easy part of handling a cHRM chunk is written,
where the ICC profile contains the required data. The more difficult
part plus guessing a gAMA value requires code to pass selected RGB values
through the profile.
png_set_keep_unknown_chunks() to be turned off if not required and causes
both read and write to behave appropriately (on read this is only possible
if the user callback is used to handle unknown chunks). The change
also removes the support for storing unknown chunks in the info_struct
if the only unknown handling enabled is via the callback, allowing libpng
to be configured with callback reading and none of the unnecessary code.
control of the unknown handling, corrects the pre-existing bug where
the per-chunk 'keep' setting is ignored and makes it possible to skip
IDAT chunks in the sequential reader (broken in earlier 1.6 versions).
There is a new test program, test-unknown.c, which is a work in progress
(not currently part of the test suite). Comments in the header files now
explain how the unknown handling works.
around architecture list; add missing ppc architecture; add architecture
options to shared library link; don't try to create a shared lib based on
missing RELEASE variable (Toby Thain).
