Routines
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28029: Check for main kids near a teacher
Used by the routine at 30102. Returns with the character number of the nearest main kid (or 0 if none of them was close enough) in A.
Input
H Teacher's character number (200-204)
28029 CALL 27886 Get the lower and upper x-coordinates of the teacher's range of vision in C and B
28032 LD L,0 Default assumption: no kids nearby
28034 EXX
28035 LD H,206 206=BOY WANDER
28037 LD BC,1535 B'=5 (main kids including ERIC), C'=255 (initial value for the distance of the nearest main kid)
28040 EXX
28041 CALL 27954 Find the first main kid within range (if any)
28044 AND A Set the zero flag if we've checked all the main kids
28045 LD A,L A=character number of the nearest kid so far, or 0 if there are none
28046 RET Z Return if we've finished checking all the main kids
28047 LD A,E A=teacher's x-coordinate
28048 EXX
28049 SUB E Subtract the x-coordinate of the kid
28050 JR NC,28054 Jump if the kid's to the left of teacher
28052 NEG
28054 CP C Is this kid closer to the teacher than the last?
28055 JR NC,28062 Jump if not
28057 LD C,A C'=distance from the teacher of the nearest kid found so far
28058 LD A,H A=character number of this kid
28059 EXX
28060 LD L,A Store the character number of the nearest kid in L
28061 EXX
28062 CALL 27981 Find the next main kid within range (if any)
28065 JR 28044 Jump back to compare distances
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