ModCS.Npc

The ModCS.Npc class represents NPCs (Also known as Entities). NPCs are game objects used for enemies, cutscenes, enemy projectiles and (some) bosses. Examples are Toroko, First Cave Critter, Puu Black, etc.

A ModCS.Npc is userdata. You may access and edit the following values from it:

Value	Type	Usage
`x`	Pixel Unit	X position of the NPC.
`y`	Pixel Unit	Y position of the NPC.
`xm`	Pixel Unit	X velocity of the NPC. This value does nothing by itself, but can be used with ModCS.Npc.Move().
`ym`	Pixel Unit	Y velocity of the NPC. This value does nothing by itself, but can be used with ModCS.Npc.Move().
`xm2`	Pixel Unit	Alternative X velocity of the NPC. This value does nothing by itself, but can be used with ModCS.Npc.Move2().
`ym2`	Pixel Unit	Alternative Y velocity of the NPC. This value does nothing by itself, but can be used with ModCS.Npc.Move2().
`tgt_x`	Pixel Unit	Target X value. This variable does nothing by itself.
`tgt_y`	Pixel Unit	Target Y value. This variable does nothing by itself.
`id`	NPC Type ID	ID of the NPC.
`flag`	Flag	Flag of the NPC.
`event`	Event	TSC Event of the NPC.
`surf`	Surface	The surface that the NPC will draw from.
`hit_voice`	Sound ID	The sound effect that will play when the NPC gets hit.
`destroy_voice`	Sound ID	The sound effect that will play when the NPC dies.
`life`	Number (Casted to integer)	The health points of the NPC.
`damage`	Number (Casted to integer)	The amount of damage the NPC deals to the player upon touching.
`exp`	Number (Casted to integer)	The XP worth of the NPC.
`smoke_size`	Number (Casted to integer)	The amount of smoke the NPC will spawn after dying. Can be from 0 to 3 (0 being no smoke being spawned upon death).
`direct`	Direction	Direction of the NPC.
`ani_no`	Number (Casted to integer)	Animation frame value. This variable does nothing by itself, but can be used to switch between animation frames.
`ani_wait`	Number (Casted to integer)	Animation timer value. This variable does nothing by itself, but can be used as a timer between animation frames.
`act_no`	Number (Casted to integer)	Act state value. This variable does nothing by itself, but can be changed with the `<ANP` TSC command.
`act_wait`	Number (Casted to integer)	Act state timer value. This variable does nothing by itself, but can be used as a timer between act states.
`count1`	Number (Casted to integer)	Counter value. This variable does nothing by itself.
`count2`	Number (Casted to integer)	Counter value. This variable does nothing by itself.
`pNpc`	NPC	Parent NPC value.

The NPC Buffer

Spawned NPCs in Cave Story are stored in a buffer (or list) of 512 entries. Although the NPC buffer size is 512, the game starts spawning NPCs at different positions in the buffer in different places. Examples include:

NPCs loaded from a PXE file start from 170.
NPCs spawned by <SNP start from 256.
Water splash entities start from 0.

When the game spawns NPCs it checks trough the NPC buffer and finds a spot that's not currently occupied by an alive NPC and replaces that spot with the NPC it's spawning. When the NPC in that spot dies, the spot is freed out for when the game decides to spawn another NPC again.

Warning

If you will be using any of the following functions for actively updating an NPC you will have to actively retrieve the NPC as well.

ModCS.Npc.GetByEvent()

ModCS.Npc.GetByEvent(event)

Searches the current buffer of spawned NPCs for one with an Event number event and returns a ModCS.Npc of that NPC. Returns a nil otherwise.

ModCS.Npc.Spawn()

ModCS.Npc.Spawn(npctype, x, y, start_index)

Spawns an NPC of NPC Type npctype on Pixel Unit coordinates x and y. If start_index is specified the NPC buffer start position for the NPC summon will be start_index. Otherwise the NPC buffer start position will be 256.

Returns a ModCS.Npc of the spawned NPC.

ModCS.Npc.GetByBufferIndex()

ModCS.Npc.GetByBufferIndex(index)

Directly gets index NPC from the NPC buffer.