Spell Queue

In order to make spell casting smoother, and not have short gaps between spells when the next is not triggered frame-perfectly, a spell queuing system exists. This system allows spells to be queued towards the end of a currently active cast, or a currently active cooldown, including the gcd.

queue_instant is the queue for instant cast spells that do not trigger a gcd. Multiple of these can be queued, as they do not interfere with other spell casts. When such spells are queued, they are appended to an array, and cast before the spell designated by the queue variable. The order in which instant, non-gcd spells are queued is the order in which they are also cast.

queue holds the ID of a single spell that either has a cast time, or triggers a gcd. Only one of these spells can be queued, because the cast time or gcd would interfere with multiple casts. This spell is triggered after the queue_instant array is emptied of queued spells. The next spell can then be queued towards the end of this spell's cast, or towards the end of the triggered gcd.

The queued spells are cast when the cast_queued function is called. This happens either when the cd of the queued spell expires, or when the preceding spell calls the finish_cast function. If the queue is triggered by an expiring cd while a cast is already ongoing, the queued spells are not triggered because the player is already casting, but the queue is not emptied. The queue will only be handled in the call to finish_cast. If the queue is triggered by finish_cast, the cd_timer timeout signal is disconnected to not erroneously trigger the queue twice, and the queue is handled.