Routines
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B517: Check And Process Objects
Used by the routine at CheckFlagAndSetDisplay_ProcessPointer.
Returns when the display flag at A01C is zero. Otherwise walks the character's objects and returns non-zero when one matches the room display parameter.
CheckFlagAndSetDisplay_CheckObjects B517 LD A,($A01C) Return if the display flag (A01C) is zero.
B51A AND A
B51B RET Z
B51C PUSH IY Keep the character record.
B51E PUSH DE
B51F PUSH IX
CheckFlagAndSetDisplay_ObjectLoop B521 CALL FollowCharacterLink Call FollowCharacterLink to follow the character link.
B524 BIT 6,(IY+$01) See whether bit 6 of the schedule entry is clear.
B528 JR Z,CheckFlagAndSetDisplay_RestoreAndReturn Jump ahead to CheckFlagAndSetDisplay_RestoreAndReturn if bit 6 of the schedule entry is clear.
B52A CALL AdjustObjectTableForSum Call AdjustObjectTableForSum to adjust the object table for this room.
CheckFlagAndSetDisplay_ProcessObject B52D PUSH IY Point HL at byte 08 of the record (IY+08).
B52F POP HL
B530 LD DE,$0008
B533 ADD HL,DE
B534 CALL ProcessObjectEntry Call ProcessObjectEntry to check the next object.
B537 CP $FF Jump back to CheckFlagAndSetDisplay_ObjectLoop if the entry is the end marker.
B539 JR Z,CheckFlagAndSetDisplay_ObjectLoop
B53B LD HL,$A034 Jump back to CheckFlagAndSetDisplay_ProcessObject while the object is not in the room on screen.
B53E CP (HL)
B53F JR NZ,CheckFlagAndSetDisplay_ProcessObject
B541 OR $01 Clear the zero flag to report that an object in the room on screen was found.
CheckFlagAndSetDisplay_RestoreAndReturn B543 POP IX Restore the saved character record, the saved source and the saved schedule entry from the stack.
B545 POP DE
B546 POP IY
B548 RET Return.
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