ALLEGRO_FILE_INTERFACE (3alleg5)

• #include <allegro5/allegro.h>
  
  typedef struct ALLEGRO_FILE_INTERFACE
  
  

A structure containing function pointers to handle a type of "file", real or virtual. See the full discussion in al_set_new_file_interface(3alleg5).

The fields are:

• void*         (*fi_fopen)(const char *path, const char *mode);
  void          (*fi_fclose)(ALLEGRO_FILE *f);
  size_t        (*fi_fread)(ALLEGRO_FILE *f, void *ptr, size_t size);
  size_t        (*fi_fwrite)(ALLEGRO_FILE *f, const void *ptr, size_t size);
  bool          (*fi_fflush)(ALLEGRO_FILE *f);
  int64_t       (*fi_ftell)(ALLEGRO_FILE *f);
  bool          (*fi_fseek)(ALLEGRO_FILE *f, int64_t offset, int whence);
  bool          (*fi_feof)(ALLEGRO_FILE *f);
  bool          (*fi_ferror)(ALLEGRO_FILE *f);
  void          (*fi_fclearerr)(ALLEGRO_FILE *f);
  int           (*fi_fungetc)(ALLEGRO_FILE *f, int c);
  off_t         (*fi_fsize)(ALLEGRO_FILE *f);
  
  

The fi_open function must allocate memory for whatever userdata structure it needs. The pointer to that memory must be returned; it will then be associated with the file. The other functions can access that data by calling al_get_file_userdata(3alleg5) on the file handle. If fi_open returns NULL then al_fopen(3alleg5) will also return NULL.

The fi_fclose function must clean up and free the userdata, but Allegro will free the ALLEGRO_FILE(3alleg5) handle.

If fi_fungetc is NULL, then Allegro\[aq]s default implementation of a 16 char long buffer will be used.