Routines
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7CAB: Check whether a character should continue walking up and down
Used by the routines at 7CD0 and 7CE1 after a character has reached a walkabout destination. It checks the signal for the event specified by byte 0x06 of the character's buffer, and returns with the carry flag reset if the signal has been raised and the character has returned to the walkabout origin.
Input
H Character number (0xB7-0xD1)
7CAB LD L,$06 Pick up the event identifier in A
7CAD LD A,(HL)
7CAE DEC L L=0x05
7CAF CALL $7C8F Has the signal been raised for this event?
7CB2 JR Z,$7CC6 Jump if not
This entry point is used by the routine at 7CE1.
7CB4 LD A,(HL) A=x-coordinate of the location relative to which the character is performing his walkabout (the 'walkabout origin'), stored in byte 0x05
7CB5 LD L,$01 Byte 0x01 of the character's buffer holds his current x-coordinate
7CB7 CP (HL) Is the character at the walkabout origin (and therefore ready to respond to the signal)?
7CB8 JR NZ,$7CBE Return him to the walkabout origin if not
7CBA DEC L Point HL at byte 0x00 of the character's buffer
7CBB BIT 0,(HL) Is the character midstride?
7CBD RET Z Return with the carry flag reset if not
7CBE SCF Signal: not ready to advance in the command list yet
7CBF LD L,$0B Fill in the new walkabout destination (either the origin or some location within 7 spaces to the left of the origin)
7CC1 LD (HL),A
7CC2 LD BC,$63ED Return with BC holding the address of the routine at 63ED
7CC5 RET
The time hasn't come or the event hasn't happened yet, so set the character off on another mini-jaunt.
7CC6 CALL $6291 A=random number
7CC9 AND $07 0<=A<=7
7CCB SUB $07 -7<=A<=0
7CCD ADD A,(HL) Add the x-coordinate of the walkabout origin to give the new walkabout destination
7CCE JR $7CBE
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