CMake

I would like to see this project migrated to cmake, I don't think it would take much time and CMake is becoming more and more the defacto build system for cross platform c/c++ projects.

When building the library with mscv on windows (Visual Studio 2022), I get the following error:

\libpes\src\sax.c(370): error C2059: syntax error: '}'

As far as I'm concerned about C code, this isn't a C standard and rather a C++ standard for object initialization. To make the project 100% cross platform I would recommend to initialize C structs manually (there are not many of them)

Example:

-struct sax_state state = {};
+struct sax_state state;
+state.level = 0;

I properly classed the control codes. They are not parts of the pes blocks. The 0xFFFF0000 between the sections are control codes, they indicate whether the file is over or if there is more to be read. They are not therefore part of the blocks themselves. They are codes to indicate if there is is something more to read it can properly gauge EOF.

I moved some sections around, and added the block description from Josh. If his data is right, it's certainly possible to parse all the higher level objects and transcode them at least naively to SVG. Even though that goal is largely a bit meh, given that nobody has actual PES files with higher level objects.

I recently went to implement version 6 to have access to the threads info in the header and consequently had to map out the data correctly. The changes are that the threads given in the header are used rather than the PEC-Threads and there's an object at the end of the PES section (after the control codes) which governs grouping and sew order. I didn't give it much time but it's usually in U32 0 0 0 0 1 0 2 0 3 0... without it PE-Design crashes, but the default values seem to work.