Function mupdf_sys::fz_page_number_from_location

pub unsafe extern "C" fn fz_page_number_from_location(
    ctx: *mut fz_context,
    doc: *mut fz_document,
    loc: fz_location
) -> c_int

Converts from chapter+page to page number. This may cause many chapters to be laid out in order to calculate the number of pages within those chapters.