On one hand, all entity names are plain/safe ASCII. But on the other hand, it would be more consistent to Base64-encode them. You decide.
Maybe iterating through the tile events should be a helper method like iterate_tile_events(const std::function<void(EventList_TileEvent &)> &callback)?
Base64-ing the XYZ data probably isn't necessary, why not move to get_output to ChatEvent::toString and ProjectileEvent::toString. That way they're consistent with other API calls where only text is Base64-ed.
To make this easier to parse, maybe it should be get_output(empty_fallback(misc_get_entity_name_upper(entity), entity->id), true, true) instead. That way clients can always safely Base64 decode without having to check if it's just an ID. Also empty_fallback could probably be merged into get_output as an empty_fallback parameter.
What was the reasoning behind using a custom structure instead of something like the standard std::queue or std::vector?
This should be static.
This is never called with a non-player sender. The type should be changed to Player *. That way, you can get rid of the isPlayer() check and the various (Player *) casts. (Yes, I know I'm contradicting past-me. Past-me was an idiot.)
And also the (Entity *) casts.
Why not call misc_get_entity_type?
This is unused (probably a victim of a merge conflict).
Why was this removed?
Should this be extern "C"? I know you've requested other method be un-mangled in the past.
There should probably be a note added about the Base64 encoding.
The "0", is no longer accurate.
This is no longer the case.
In compat mode, this should be the name.
It does now.
And also the (Entity *) casts.
Pretty sure this has the correct ID for non-local players now.
Just open a single player world and type something in chat: