Routines
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BECE: Handler: Turn-Based Events
Used by the routine at GameLoop.
Count down the timed threats and, when one expires, run its handler.
Handler_TurnBasedEvents BECE LD A,($BA36) Jump to Handler_TurnBasedEvents_Scenic when the event mask is zero.
BED1 OR A
BED2 JR Z,Handler_TurnBasedEvents_Scenic
BED4 LD C,A Count the eight event bits, and skip a threat whose bit is clear.
BED5 LD B,$08
Handler_TurnBasedEvents_Loop BED7 SRL C
BED9 JR NC,Handler_TurnBasedEvents_Next
BEDB LD DE,$0000 DE=0000.
BEDE LD HL,$BA37 Count this threat's timer down. Leave it alone while time remains.
BEE1 LD A,$08
BEE3 SUB B
BEE4 LD E,A
BEE5 ADD HL,DE
BEE6 DEC (HL)
BEE7 JR NZ,Handler_TurnBasedEvents_Next
BEE9 LD IX,($BADE) Take this threat's handler.
BEED SLA E
BEEF ADD IX,DE
BEF1 LD L,(IX+$00)
BEF4 LD H,(IX+$01)
BEF7 PUSH BC Keep the bit scan safe, return here, and jump to that handler.
BEF8 LD DE,$BEFD
BEFB PUSH DE
BEFC JP (HL)
BEFD POP BC Restore the bit scan from the stack.
Handler_TurnBasedEvents_Next BEFE DJNZ Handler_TurnBasedEvents_Loop Repeat from Handler_TurnBasedEvents_Loop for the remaining event bits.
Handler_TurnBasedEvents_Scenic BF00 NOP Start at the scenic list. Jump to Handler_TurnBasedEvents_Return when the scenic count is zero.
BF01 LD HL,$BA48
BF04 LD A,($BB00)
BF07 OR A
BF08 JR Z,Handler_TurnBasedEvents_Return
BF0A LD B,A Start at the first scenic entry.
BF0B JR Handler_TurnBasedEvents_ScenicSlot
Handler_TurnBasedEvents_ScenicAdvance BF0D INC HL Advance to the next scenic entry.
Handler_TurnBasedEvents_ScenicSlot BF0E LD A,(HL) Jump to Handler_TurnBasedEvents_ScenicNext when this scenic slot is empty.
BF0F OR A
BF10 JR Z,Handler_TurnBasedEvents_ScenicNext
BF12 LD A,($BA9B) Jump to Handler_TurnBasedEvents_ScenicNext when this event is already in the current room.
BF15 CP (HL)
BF16 JR Z,Handler_TurnBasedEvents_ScenicNext
BF18 PUSH HL Call GetTableEntry to fetch this event's room list.
BF19 PUSH BC
BF1A LD A,($BB00)
BF1D SUB B
BF1E LD E,A
BF1F LD IX,$BA9C
BF23 CALL GetTableEntry
BF26 LD A,($5C78) Use the frame counter as a step count and start at the first room in the list.
BF29 LD B,A
BF2A LD A,$FF
Handler_TurnBasedEvents_RoomWalk BF2C LD L,(IX+$00)
BF2F LD H,(IX+$01)
BF32 JR Handler_TurnBasedEvents_RoomCheck
Handler_TurnBasedEvents_RoomStep BF34 INC HL Step to the next room in the list.
Handler_TurnBasedEvents_RoomCheck BF35 CP (HL) Jump back to Handler_TurnBasedEvents_RoomWalk when the end marker matches.
BF36 JR Z,Handler_TurnBasedEvents_RoomWalk
BF38 DJNZ Handler_TurnBasedEvents_RoomStep Repeat from Handler_TurnBasedEvents_RoomStep until the step count runs out.
BF3A LD A,(HL) Take the room the walk landed on.
BF3B POP BC Restore the scenic counter and scenic entry pointer from the stack.
BF3C POP HL
BF3D LD (HL),A Store that room back in this scenic slot.
Handler_TurnBasedEvents_ScenicNext BF3E DJNZ Handler_TurnBasedEvents_ScenicAdvance Repeat from Handler_TurnBasedEvents_ScenicAdvance for the remaining scenic events.
Handler_TurnBasedEvents_Return BF40 RET Return.
View the equivalent code in;
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