Updating libpng: Add libpng version 1.5.1

This is a clean copy of the official libpng 1.5.1 distribution, except
that various extraneous stuff (examples, tests, etc) have been removed,
as usual. The minor modifications to build it in Qt will follow in a
separate commit.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/3rdparty/libpng/TODO b/src/3rdparty/libpng/TODO
new file mode 100644
index 0000000..6e1f028
--- /dev/null
+++ b/src/3rdparty/libpng/TODO
@@ -0,0 +1,27 @@
+/*
+TODO - list of things to do for libpng:
+
+Final bug fixes.
+Better C++ wrapper/full C++ implementation?
+Fix problem with C++ and EXTERN "C".
+cHRM transformation.
+Remove setjmp/longjmp usage 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).
+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.
+Switch to the simpler zlib (zlib/libpng) license if legally possible.
+Extend pngvalid.c to validate more of the libpng transformations.
+
+*/