SMBX NPC Offsets

This is the memory map for the npc struct. This struct is not fully analysed. Any help is appreciated! Please note that the data may not be fully 100% accurate.

NPC Memory (0x158 bytes)
Name	Memory address	Memory type	Description
Attached layer name	NPC+0x00	VB6 String Pointer	The attached layer name.
Unknown	NPC+0x04	FIELD_WORD	Unknown
Unknown decrementing timer	NPC+0x06	FIELD_WORD	Unknown decrementing timer
Collides below	NPC+0x0A	FIELD_WORD	Set to 2 when touching a block below
Collides left	NPC+0x0C	FIELD_WORD	Set to 2 when touching a block to the left
Collides above	NPC+0x0E	FIELD_WORD	Set to 2 when touching a block above
Collides right	NPC+0x10	FIELD_WORD	Set to 2 when touching a block to the right
Unknown	NPC+0x18	FIELD_FLOAT	NPC x-axis movement related, perhaps temporary
Is Underwater?	NPC+0x1C	FIELD_WORD	underwater state (2 is underwater, 0 is no)
Hit Counter (ie for hammers)	NPC+0x24	FIELD_WORD	Hit counter, for point calculation
Invincibility to Sword	NPC+0x26	FIELD_WORD	Invincibility frame countdown, for sword attacks
Activate event layer name	NPC+0x2C	VB6 String Pointer	Activate event layer name
Death event layer name	NPC+0x30	VB6 String Pointer	Death event layer name
Talk event name?	NPC+0x34	VB6 String Pointer	Talk event name?
No More Objs event layer name	NPC+0x38	VB6 String Pointer	No More Objs event layer name
Layer name	NPC+0x3C	VB6 String Pointer	Layer name
Unknown	NPC+0x40	FIELD_WORD	Unknown (some sort of hide value if -1)
Activated	NPC+0x44	FIELD_WORD	Activated / interacted with player flag
Friendly	NPC+0x46	FIELD_WORD	Friendly (on = -1)
Don't Move	NPC+0x48	FIELD_WORD	Don't Move (on = -1)
NPC Message text	NPC+0x4C	VB6 String Pointer	NPC Message text
Is a generator	NPC+0x64	FIELD_WORD	Is a generator?
Generator delay setting	NPC+0x68	FIELD_FLOAT	Generator delay setting
Generator firing rate	NPC+0x6A	FIELD_WORD	Generator firing rate
Generator delay countdown	NPC+0x6C	FIELD_FLOAT	Generator delay countdown
Direction to generate NPC?	NPC+0x70	FIELD_WORD	Direction to generate NPC?
Layer to spawn NPC on	NPC+0x72	FIELD_WORD	Which layer to spawn NPC on
Invalidity/offscreen flag?	NPC+0x74	FIELD_WORD	Invalidity or offscreen flag?
X position	NPC+0x78	FIELD_DOUBLE	X position
Y position	NPC+0x80	FIELD_DOUBLE	Y position
Height	NPC+0x88	FIELD_DOUBLE	Height
Width	NPC+0x90	FIELD_DOUBLE	Width
X Speed	NPC+0x98	FIELD_DOUBLE	X Speed
Y Speed	NPC+0xA0	FIELD_DOUBLE	Y Speed
Spawn X	NPC+0xA8	FIELD_DOUBLE	Spawn X
Spawn Y	NPC+0xB0	FIELD_DOUBLE	Spawn Y
GFX Height	NPC+0xB8	FIELD_DOUBLE	GFX Height
GFX Width	NPC+0xC0	FIELD_DOUBLE	GFX Width
Unknown	NPC+0xD8	FIELD_FLOAT	Unknown
Respawn Id	NPC+0xDC	FIELD_WORD	Respawn Identity. 0 means doesn't respawn, otherwise same as 0xE2
Id	NPC+0xE2	FIELD_WORD	Sprite GFX index/Identity
Animation frame	NPC+0xE4	FIELD_WORD	Animation frame
Animation timer	NPC+0xE8	FIELD_FLOAT	Animation timer
Direction faced	NPC+0xEC	FIELD_FLOAT	Direction faced (Unknown difference from 0x118)
NPC AI 1	NPC+0xF0	FIELD_DOUBLE	Multipurpose NPC AI state/timer 1
NPC AI 2	NPC+0xF8	FIELD_DOUBLE	Multipurpose NPC AI state/timer 2
NPC AI 3	NPC+0x100	FIELD_DOUBLE	Multipurpose NPC AI state/timer 3
NPC AI 4	NPC+0x108	FIELD_DOUBLE	Multipurpose NPC AI state/timer 4
NPC AI 5	NPC+0x110	FIELD_DOUBLE	Multipurpose NPC AI state/timer 5
Direction faced	NPC+0x118	FIELD_FLOAT	Direction faced
Bounce off block	NPC+0x120	FIELD_WORD	-1 means just bounced off a block to change direction
Kill flag	NPC+0x122	FIELD_WORD	Kill/Kill effect (0 = No kill/ 1-? Kill effect with kill)
Unknown	NPC+0x124	FIELD_WORD	Note: Must be set to -1 when spawning a new NPC
Offscreen flag	NPC+0x128	FIELD_DOUBLE	Offscreen flag (-1 = offscreen)
Offscreen countdown timer?	NPC+0x12A	FIELD_WORD	Offscreen countdown timer. 180 is onscreen. Set to 0 to force despawn.
Player holding index?	NPC+0x12C	FIELD_WORD	Possibly the index of the player holding the NPC. Setting to 1 or higher deactivates block collision when grabbed but a value of 1 disrupts the player's ability to pick up other objects
Grab Timer?	NPC+0x12E	FIELD_WORD	Related to grabbing npcs. Starts at 30 then quickly returns to 0 when released.
Collides with NPCs	NPC+0x136	FIELD_WORD	-1 indicates it collides with other NPCs. Doubles as a "grabbed" flag
Contained Within	NPC+0x138	FIELD_WORD	Set to the container's ID when contained in another NPC (i.e. jar)
Current Section	NPC+0x146	FIELD_WORD	Current section this NPC is on
Hit Count	NPC+0x148	FIELD_FLOAT	Boss Hit count
NPC Collision	NPC+0x152	FIELD_WORD	Seems to be set to -1 for a bullet when it destroys another NPC. May apply to all 0x136-related collisions but untested.
Invincibility frames	NPC+0x156	FIELD_WORD	Invincibility frame countdown for all sources of harm