load_datafile_callback(3)

💖 load_datafile_callback(3) 💖

okay bestie, so this one lives in the Allegro manual and it's literally the cutest little loading-screen hack you've ever seen. let's get into it 🫶

---

✨ NAME ✨

load_datafile_callback — loads a datafile into memory, and calls a hook once per object. part of the Allegro game programming library, obviously 💅

---

🌸 SYNOPSIS 🌸

#include <allegro.h>

DATAFILE *load_datafile_callback(const char *filename, void
(*callback)(DATAFILE *d));

---

🦋 DESCRIPTION 🦋

so the whole vibe here is: you load a datafile into memory, but every single time an object gets read, Allegro hits up your specified hook function and passes it a pointer to the object it just read. one call per object, no cap. 🎀

and the way you use this?? it's giving extremely simple loading screens. every time the hook fires, you update the screen so your user knows the program is still loading from disk and hasn't just, like, died. iconic.

here's the example, and yes you can copy it, I got you:

void load_callback(DATAFILE *dat_obj)
{
   static const char indicator[] = "-\\|/-.oOXOo.";
   static int current = 0;

   /* Show a different character every time. */
   textprintf_ex(screen, font, 0, 0, makecol(0, 0, 0),
                 makecol(255, 255, 255), "%c Loading %c",
                 indicator[current], indicator[current]);
   /* Increase index and check if we need to reset it. */
   current++;
   if (!indicator[current])
      current = 0;
}
   ...
   dat = load_datafile_callback("data.dat", load_callback);

like. a little spinner. spinning. while your stuff loads. we love a progress indicator era 💚

---

⭐ RETURN VALUE ⭐

returns a pointer to the DATAFILE, or NULL if something went wrong 😭. and bestie, please — remember to free this DATAFILE later, because otherwise you're leaking memory and that's not the main character energy we're going for. clean up after yourself, periodt.

---

👑 SEE ALSO 👑

• load_datafile(3)
• unload_datafile(3)
• load_datafile_object(3)
• set_color_conversion(3)
• fixup_datafile(3)
• packfile_password(3)
• find_datafile_object(3)
• register_datafile_object(3)

---

k that's the whole page bestie, go forth and load ur datafiles with style 💜

this has been your girl, reporting live from Allegro version 4.4.3 — mwah, slay, bye 🎀✨