Back to Skool: Routine at 6C9C

6C9C: Check whether any characters were punched

Used by the routine at 77C8. Returns with the carry flag reset if someone was hit in the face, and D holding the character number of the stricken one.

Input
B	Number of potential victims to check
C	0x00 if the puncher is facing right, 0x80 if left
D	Character number of the first potential victim to check
H	Puncher's character number: 0xCF (ANGELFACE) or 0xD2 (ERIC)

6C9C

CALL $6CAC

Are any characters in front of the puncher's fist?

6C9F

RET C

Return if not

6CA0

LD E,$00

6CA2

LD A,(DE)

A=animatory state of the character in front of the puncher's fist

6CA3

AND $80

Keep only the 'direction' bit (bit 7)

6CA5

XOR C

Compare with the direction bit of the punching character

6CA6

RET Z

Return with the carry flag reset if the punched character was facing the puncher (i.e. was hit in the face)

6CA7

INC D

Otherwise move on to the next potential victim

6CA8

DJNZ $6C9C

Jump back to consider any remaining potential victim

6CAA

SCF

Signal: no characters were hit

6CAB

RET