[kristianp]

Yes, this made me want to reach for a safer language, I could see the potential buffer overflows loud and clear:

    void          bmp_init(void *, long width, long height);

[DougBTX]

The corollary of "no error handling" is "caller must be perfect", it is the opposite to defensive coding. I can see the appeal, it puts minimal constraints on the caller, in a sense making the library functions as flexible as possible, but exposing an API so easy to misuse seems reckless, even if the API is elegant in its own way.