PACKFILE_VTABLE(3alleg4)

💖 PACKFILE_VTABLE 💖

okay bestie, so this is a page from the Allegro manual — the 3alleg4 one, aka the Allegro game programming library, and this specific page is all about the Packfile vtable structure, for custom packfiles. yes queen, custom packfiles. we're doing this. 🎀

✨ SYNOPSIS ✨

#include <allegro.h>

typedef struct PACKFILE_VTABLE

🌸 DESCRIPTION 🌸

so the way this works is, it's giving struct. it's giving vtable. and inside that vtable you've got all these function pointers you gotta fill in:

int pf_fclose(void *userdata);
int pf_getc(void *userdata);
int pf_ungetc(int c, void *userdata);
long pf_fread(void *p, long n, void *userdata);
int pf_putc(int c, void *userdata);
long pf_fwrite(const void *p, long n, void *userdata);
int pf_fseek(void *userdata, int offset);
int pf_feof(void *userdata);
int pf_ferror(void *userdata);

This is the vtable which must be provided for custom packfiles, which then can read from and write to wherever you like (eg. files in memory). 🧠✨

and here's the part where you listen to me: you should provide all the entries of the vtable, even if they are empty stubs doing nothing, to avoid Allegro (or you) calling a NULL method at some point.

not me leaving a NULL method in there and then everything explodes 😭💀 like no, fr fr, fill in every single one. even the do-nothing stubs. it's giving "safety first" and honestly it's iconic of you to do it. 💅

👑 SEE ALSO 👑

• pack_fopen_vtable(3alleg4)
• expackf(3alleg4)

okay that's the whole page, you ate that 🍓💜 this was brought to you by Allegro, version 4.4.3 — go forth and write your custom packfiles, bestie, the main character energy is immaculate 🌈⭐🦋