Avalon: Routine at 55818

55818: Maroc's room number has changed - identify new room number

Used by the routine at 55628.
Maroc has left a room - all door, creature and object data from the room he's left has been dealt with in the previous routine.
55818	LD A,(60087)	Get room number
55821	CP 224	Check if it's a tunnel room (room numbers 224-255)
55823	JR NC,55837	If so, there are no creatures to deal with, so skip the next few instructions
Standard (non-tunnel room). Copy the room's creature data byte (60343), calculated in the previous routine, in the relevant room's creature data set at 26512.
55825	DEC A	Offset starts at 0, not 1, so decrement room number
55826	LD C,A	Use room number as an offset in BC register pair
55827	LD B,0	Use room number as an offset in BC register pair
55829	LD HL,(56048)	Address pointer for the room creature data set at 27532
55832	ADD HL,BC	Add offset (with C = room number)
55833	LD A,(60343)	Byte indicating which creatures are in the room (that Maroc is leaving)
55836	LD (HL),A	Copy into the room creature data at 26512
Get new room number:
55837	LD A,(60080)	Get (new) room number data byte
55840	CP 255	If byte set to 255 it indicates that the room number needs to be calculated, so will need calculating using the connecting door table at 26512
55842	JR NZ,55857	If already calculated, skip the next few instructions
55844	LD HL,(60085)	Address pointer to connecting door data at 26512
55847	LD A,(60087)	Get current room number
55850	CP (HL)	The connecting room will either be byte 2 or 3 (1 door, two rooms) Is the current room equal to byte 2 in the door table?
55851	JR NZ,55854	If not, the new room is byte 2
55853	INC HL	If so, we need byte 3
55854	LD A,(HL)	Get the room byte from the connecting door table
55855	JR 55874	Get the room byte from the connecting door table
If the new room number is already set/calculated, it means it's been changed by some event during the game cycle. For example, if Maroc: is out of energy (room set to room #1) casts a spell such as SUMMON or WAYSTONE, that teleports him to a new room If so, set Maroc's position in the new room at the point of the room's left wall-floor connector. See Bugs - Teleport spells
55857	LD C,A	Calculated room number - temp store in C
55858	LD A,48	Set Maroc's vertical pixel position in the room to 48 pixels
55860	LD (60276),A
55863	LD A,16	Set Maroc's horizontal room position (4-pixel/half-character steps) to 16
55865	LD (60277),A
55868	LD A,0
55870	LD (60278),A	Set Maroc's room vertical position to 0
55873	LD A,C	Retrieve byte (60080) from C register
Maroc's room has now changed, so he's either gone through a door, run out of energy, or has teleported somewhere.
55874	LD (60087),A	Store new room number (e.g. = room #1 when Maroc is out of energy, room #61 for SUMMON)
55877	LD A,(60128)	Check Maroc's energy level
55880	CP 0	Is it zero?
55882	JP NZ,49415	If not 0, Maroc hasn't run out of energy, so if he hasn't just gone through a door he's probably cast some sort of teleport spell. If this is the case, jump out here and initialize the data for his new room. Otherwise, Maroc is out of energy - continue to the next routine.