Add libpng 1.4.0

This is a clean copy of libpng 1.2.40, except that the contribs
directory has been removed, as usual. Our build modifications
will follow in a separate commit.

1 files changed, 31 insertions, 0 deletions

diff --git a/src/3rdparty/libpng/TODO b/src/3rdparty/libpng/TODO
new file mode 100644
index 0000000..7fe1ddf
--- /dev/null
+++ b/src/3rdparty/libpng/TODO
@@ -0,0 +1,31 @@
+/*
+TODO - list of things to do for libpng:
+
+Final bug fixes.
+Improve API by hiding the png_struct and png_info structs.
+Finish work on the no-floating-point version (including gamma compensation)
+Better C++ wrapper/full C++ implementation?
+Fix problem with C++ and EXTERN "C".
+cHRM transformation.
+Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+Add "grayscale->palette" transformation and "palette->grayscale" detection.
+Improved dithering.
+Multi-lingual error and warning message support.
+Complete sRGB transformation (presently it simply uses gamma=0.45455).
+Man pages for function calls.
+Better documentation.
+Better filter selection
+   (counting huffman bits/precompression?  filter inertia?  filter costs?).
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Build gamma tables using fixed point (and do away with floating point entirely).
+Avoid building gamma tables whenever possible.
+Use greater precision when changing to linear gamma for compositing against
+  background and doing rgb-to-gray transformation.
+Investigate pre-incremented loop counters and other loop constructions.
+Add interpolated method of handling interlacing.
+Provide for conditional compilation of 16-bit support (except for the
+  initial stripping down to 8-bits when reading a 16-bit PNG datastream).
+Switch to the simpler zlib (zlib/libpng) license if legally possible.
+
+*/