AL_INIT_USER_EVENT_SOURCE(3)

💖 NAME 💖

okay so bestie, this is al_init_user_event_source(3) from the Library Functions Manual — the Allegro 5 API function that sets up an event source for emitting user events ✨

✨ SYNOPSIS ✨

#include <allegro5/allegro.h>

void al_init_user_event_source(ALLEGRO_EVENT_SOURCE *src)

🦋 DESCRIPTION 🦋

So what this icon does is initialise an event source for emitting user events. That's the whole vibe. But hear me out: the space for the event source must already have been allocated before you call this. She is not out here doing your malloc for you, bestie — she just initialises what's already there 💅

One possible way of creating custom event sources is to derive other structures with ALLEGRO_EVENT_SOURCE at the head, e.g.:

              typedef struct THING THING;

              struct THING {
                  ALLEGRO_EVENT_SOURCE event_source;
                  int field1;
                  int field2;
                  /* etc. */
              };

              THING *create_thing(void)
              {
                  THING *thing = malloc(sizeof(THING));

                  if (thing) {
                      al_init_user_event_source(&thing->event_source);
                      thing->field1 = 0;
                      thing->field2 = 0;
                  }

                  return thing;
              }

The advantage here is that the THING pointer will be the same as the ALLEGRO_EVENT_SOURCE pointer. Events emitted by the event source will have the event source pointer as the source field, from which you can get a pointer to a THING by a simple cast (after you make sure to check that the event is of the correct type). It's giving pointer math but make it cute 😌

However, it is only one technique and you are not obliged to use it. No pressure, bestie — do what works for your code 🫶

⚠️ real talk: the user event source will never be destroyed automatically. You must destroy it manually with al_destroy_user_event_source(3). Don't leave her hanging, okay? 😭

🌈 SEE ALSO 🌈

• ALLEGRO_EVENT_SOURCE(3)
• al_destroy_user_event_source(3)
• al_emit_user_event(3)
• ALLEGRO_USER_EVENT(3)

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byeee bestie 🫶 this has been the Allegro reference manual (source/version vibes: iconic; date: not listed in this footer, so she's a mystery 💀) — now go init that event source and slay ✨💖