I ported LodePNG but I'm having a few issue I can't seem to resolve. It compiles ok, however all chunks report a bad CRC32. Also all the Alder32 check-sums are bad as well. However, if these checks are disabled (an option) then it will load some png files. So obviously there's something wrong with my port. Some png files report chunk sizes over 2gb which is impossible. Looking at them with a file editor reveals correct chunk sizes, so something is going wrong while its scanning the chunks. If anyone into PureC is willing to help or have a look at it, the original project is here: http://lodev.org/lodepng/
My ported sources are at my public dropbox: https://www.dropbox.com/sh/hk65mapqd3fm ... KqQTa?dl=0
(In folder \lodepng)
You don't need zView, it builds a standalone prg file, just drop a png file on it, after building it.
The idea was to wrap it into a codec for vZview, which I did already, but with all the problems noted above. It's loading maybe about 50% of the png files I try. It weighs in at about 27kb, which is quite a bit smaller than the original png.ldg module supplied with zView. It could be used directly in other projects as well, if it was reliable.