Routines
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56959: Identify state of object in current room
Used by the routines at 51968, 56028 and 56908.
Input
HL Address pointer to room/object data at 29551
The fifth byte of an object's data set (held in the object buffer at 60297) holds its state, which can change. For example a chest can be closed (state = 1) and be moved to state 2 (open).
This routine identifies the state of the object and copies the 4 bytes for this state into the additional buffer at 60301.
56959 LD (60290),HL Store address pointer (data at 29551)
56962 LD DE,60293 Copy the first 8 bytes of this object's data into buffer at 60293
56965 LD BC,8
56968 LDIR
56970 LD A,(60297) State number of this object. All standard object 'sets' start at 1
56973 LD C,A
56974 CP 0
56976 JR Z,57001
56978 DEC A Decrement state number
56979 CP 0 Is this the object's current state?
56981 JR Z,56990
56983 LD DE,4 If so, skip 4 bytes for each state the object has advanced to
56986 LD B,A
56987 ADD HL,DE
56988 DJNZ 56987
Current object state found:
56990 LD B,4 Copy the 4 data bytes for this object state into the additional buffer at 60301
56992 LD DE,60301
56995 LD A,(HL)
56996 LD (DE),A
56997 INC HL
56998 INC DE
56999 DJNZ 56995
Skip over any additional data sets for this object
57001 LD A,(60300) Get the count of additional 4 byte data sets for this object
57004 SUB C Subtract the current state number, whose data has already been copied over to the buffer
57005 JR Z,57014 If zero, there's no more data for this set - jump straight to RET
57007 LD DE,4 ...Otherwise, skip over the remaining object states
57010 LD B,A
57011 ADD HL,DE
57012 DJNZ 57011
This entry point is used by the routine at 56908.
57014 RET Object set now dealt with
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