xyz_to_meta ()
int
xyz_to_meta (char *path,
size_t len,
const char *dir,
int x,
int y,
int z);
Returns the path to the meta-tile and the offset within the meta-tile
metatile_read ()
int
metatile_read (const char *dir,
int x,
int y,
int z,
char *buf,
size_t sz,
int *compressed,
char *log_msg);
Reads into buf upto size specified by sz
Returns whether the file is in a compressed format (possibly only gzip)
Error messages returned in log_msg