EventEngineNotes.txt

/!\ FE8 ONLY HERE

Event Code Format: (Size: 2 (short))
	bit 0-7   : CodeID    | Event Code Id, valid range are 00-xx and 80-yy (xx and yy are size of some routine arrays)
	bit 8-11  : CodeSize  | Event Instruction size. If the Event Routine returns 0 or 2, the event cursor will advance by this value times 2
	bit 12-15 : CodeParam | Depends (read by routines usually) (usually defines what behaviour is to be had)

Event Code Format: (Condensed)
	0xCCSP
		0xCC is CodeID
		0x0S is CodeSize
		0x0P is CodeParam
	Example 0x2A21:
		CodeID    = 0x2A (Move to Chapter codes)
		CodeSize  = 0x02 (2 shorts aka a word)
		CodeParam = 0x01

Event Routine return value:
	0: Event cursor added to set value (see Event Code Format) and Continue Execution
	2: Event cursor added to set value (see Event Code Format) and Yield
	3: Yield
	5: Kill the Event Engine
	Anything else: Continue Execution

6C_08591AC0 & 6C_08591AF8 (Event Engine):
	2C | word  | some routine pointer
	30 | word  | some event pointer
	34 | word  | some other event pointer
	38 | word  | current event cursor
	3C | short | Event State Bits:
					bit 0 (& 0x01): 
					bit 1 (& 0x02): 
					bit 2 (& 0x04): Currently Skipping? (like when start is pressed or something)
					bit 3 (& 0x08): 
	3E | short | Timer for STAL codes
	42 | byte  | 
	48 | word  | UNIT pointer

MuCtr 6C:
	2C | word  | Unit Struct pointer
	30 | word  | MOVEUNIT pointer
	34 | word  | Event Move Buffer pointer
	38 | short | Event Move Buffer Entry Count

EVENT CODES:
	ID 00 "Null"
		Does Nothing, returns 0
	
	ID 01 "End"
		If Event bit 0 is set:
			returns 5 (Ends event execution)
		
		Subcode 0001b "ENDB"
			Clears Event Call Stack
		Else "ENDA"
			Nothing specific
		
		Goes back to last event call
		
		return 5 if no return (End event exec)
		return 1 otherwise (Continue)
	
	ID 02 "Event ID & Event Bit manipulation":
		Subcode 0000b "EVBIT_F <bit>"
			Clears event bit <bit>
		
		Subcode 1000b "EVBIT_T <bit>"
			Sets event bit <bit>
		
		Subcode 0001b "ENUF <evid>"
			Unsets event id <evid>
		
		Subcode 1001b "ENUT <evid>"
			Sets event id <evid>
		
		return 0 (Advance & Continue)
	
	ID 03 "Event ID & Event Bit Check":
		Subcode 0000b "CHECK_EVBIT <bit>:2"
			Slot C = State of event bit <bit>
		
		Subcode 0001b "CHECK_EVENTID <evid>:2"
			Slot C = State of event id <evid>
		
		return 0 (Advance & Continue)
	
	ID 04 "Random Number Generation":
		All "RANDOMNUMBER <max>:2"
			Slot C = Random Integer in range 0 to <max> inclusive
		
		return 0 (Advance & Continue)
	
	ID 05 "Slot Set":
		All "SVAL <slot>:2 <value>:4"
			Slot <slot> = <value>
		
		return 0 (Advance & Continue)
	
	ID 06 "Slot Operations":
		Subcode 0: SADD
		Subcode 1: SSUB
		Subcode 2: SMUL
		Subcode 3: SDIV
		Subcode 4: SMOD?
		Subcode 5: SAND
		Subcode 6: SORR
		Subcode 7: SXOR
		Subcode 8: SLSL
		Subcode 9: SLSR
		Other: return 6 (Continue)
		
		"<op> <param>:2"
		
		<param>:
			bit 0-3:  Dest Slot
			bit 4-7:  LSorc Slot
			bit 8-11: RSorc Slot
		
		Execututes operation between values in LSorc and RSorc, stores result in Dest
		return 0 (Advance & Continue)
	
	10 | EVBIT_MODIFY
	2A | MNCH, MNC2, MNC3, MNTS

UNIT LOADING:
	LOAD1 Param Ptr
	LOAD2 Ptr @ LOAD1 but Param is fixed to 2
	LOAD3 Param Ptr @ LOAD1 but also calls FE8U:80125C0 on the UNIT list which I don't really get?
	LOAD4 Param @ loads skirmish enemies

	Param meaning:
	- 0 means do not load if unit is dead and player unit.
	- 1 means no extra load constraints.
	- 2 means load as cutscene unit unless unit is dead and player unit and not either of Seth, Myrrh, Innes or L'Arachel.