libUEMF
A C99 implementation for reading/writing WMF and EMF Graphic Metafiles
...Instead, for each metafile record type, and each object type incorporated into such a record, it provides corresponding *_set, *_get, *_print, and *_swap functions. Additional functions are provided for assembling the metafile in memory, debugging, and providing any needed byte swapping (an EMF file's internal data representation is always Little Endian.)