BeRoPNG - A very tiny but complete PNG loader

[BeRo]

function Swap32(x:word):word;
begin
 result:=(Swap16(x and $ffff) shl 16) or Swap16((x and $ffff0000) shr 16);
end;

BeRoPNG should be portable and small (even at source code level) at the same time, so that it should containing no or only few inline assembler parts, but a good optimizing compiler with inline-support and good code peephole replace templates should optimize this with "bswap eax" on x86-32 and x86-64 (what Delphi&FPC does it not yet, but some C/C++ compilers. My big hope for this is the LLVM backend for FPC). The "and $ffff0000" is just for that it's more readable, the compiler will optimizing it out, but that is something you should know (as you probably already do).