Npc
Npc head-icon specific packets are used to render a head icon over a given NPC to one user alone, and not the rest of the world. It is worth noting, however, that the head icon will only be set if the given NPC was already registered by the NPC INFO packet. If a given NPC is removed from the local view through NPC INFO, the head icon goes alongside, and will not be automatically restored should that NPC re-enter the local view.
Throws
if the headIconSlot is not in range of 0 to 7 (inclusive)
Properties
the slot of the head icon, a value of 0 to 7 (inclusive)
the cache group id of the sprite. While the client reads a 32-bit integer for this value, the client does not allow for a value greater than 65535 to be used due to cache limitations, thus, in order to compress the packet even further, we also limit the id to a maximum of 65535.
the index of the sprite within the sprite file in the cache. Note that this is not the id of the file in the cache group, as for sprites, this is always zero. Each sprite file itself defines a number of sprites - this is the index in that list of sprites.