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Routines |
H | Character number of teacher (163-166) |
30890 | PUSH HL | |
30891 | LD A,(32763) | Copy ERIC's status flags from 32763 to A |
30894 | LD HL,44130 | Pick up ERIC's coordinates in DE |
30897 | LD E,(HL) | |
30898 | DEC L | |
30899 | LD D,(HL) | |
30900 | LD BC,910 | B=3 (number of main kids besides ERIC), C=142 (LSB of 32654) |
30903 | BIT 2,A | Is ERIC jumping? |
30905 | JR Z,30924 | Jump if not |
30907 | LD A,D | A=ERIC's y-coordinate |
30908 | LD D,155 | 155=top floor |
30910 | CP 156 | Is ERIC jumping on the top floor? |
30912 | JR C,30927 | Jump if so |
30914 | LD D,162 | 162=middle floor |
30916 | CP 163 | Is ERIC jumping on the middle floor? |
30918 | JR C,30927 | Jump if so |
30920 | LD D,169 | 169=bottom floor |
30922 | JR 30927 | |
30924 | CALL 28310 | Get the floor nearest ERIC (155, 162, 169) in D |
30927 | LD (32652),DE | Store ERIC's normalised coordinates in 32652 |
30931 | LD H,167 | 167=BOY WANDER |
30933 | CALL 28304 | D=floor nearest the kid (155, 162, 169) |
30936 | LD L,C | L=142, 144 or 146 |
30937 | LD A,H | Store the kid's character number in A temporarily |
30938 | LD H,127 | HL=32654, 32656 or 32658 |
30940 | LD (HL),E | Store the kid's normalised coordinates here |
30941 | INC L | |
30942 | LD (HL),D | |
30943 | INC L | Point HL at the next normalised coordinates slot |
30944 | LD C,L | Save L in C temporarily |
30945 | LD H,A | Restore the kid's character number (167-169) to H |
30946 | INC H | Next kid |
30947 | DJNZ 30933 | Jump back until the three main kids have been done |
30949 | POP HL | Restore the teacher's character number (163-166) to H |
30950 | PUSH HL | |
30951 | LD L,98 | Pick up the teacher's coordinates in DE |
30953 | LD E,(HL) | |
30954 | DEC L | |
30955 | LD D,(HL) | |
30956 | CALL 28327 | Get the lower and upper limits of the teacher's visibility range in C and B |
30959 | LD HL,32659 | 32659 holds EINSTEIN's normalised y-coordinate |
30962 | LD A,4 | There are four main kids to check |
30964 | PUSH AF | |
30965 | LD A,(HL) | Pick up a kid's normalised y-coordinate |
30966 | DEC HL | Point HL at the kid's x-coordinate |
30967 | CP D | Compare the normalised y-coordinate with the teacher's y-coordinate |
30968 | LD A,(HL) | A=kid's x-coordinate |
30969 | LD (HL),255 | Default assumption: kid and teacher are on different floors |
30971 | JR NZ,30987 | Jump unless the kid's normalised y-coordinate matches the teacher's y-coordinate |
30973 | CP B | Jump forward if the teacher cannot see the kid |
30974 | JR Z,30978 | |
30976 | JR NC,30987 | |
30978 | CP C | |
30979 | JR C,30987 | |
30981 | SUB E | A=distance between the teacher and the kid (possibly < 0) |
30982 | JR NC,30986 | Jump if the kid is to the right of the teacher (A>=0) |
30984 | NEG | |
30986 | LD (HL),A | Store the absolute distance between the teacher and the kid (if they are close to each other) |
30987 | DEC HL | Point HL at the normalised y-coordinate of the next main kid and jump back until all four have been checked |
30988 | POP AF | |
30989 | DEC A | |
30990 | JR NZ,30964 |
30992 | INC HL | HL=32652 (holding ERIC's distance from the teacher) |
30993 | LD B,4 | There are four main kids to consider |
30995 | LD A,255 | 255 was used to signal that the kid was not on the same floor as the teacher |
30997 | CP (HL) | When this loop is finished, A will hold the distance between the teacher and the closest main kid (or 255 if none of the kids were nearby) |
30998 | JR C,31001 | |
31000 | LD A,(HL) | |
31001 | INC HL | |
31002 | INC HL | |
31003 | DJNZ 30997 | |
31005 | INC A | Were any of the main kids close to the teacher? |
31006 | JR NZ,31010 | Jump if so |
31008 | POP HL | Restore the teacher's character number to H |
31009 | RET |
31010 | DEC A | A=distance between the teacher and the nearest kid |
31011 | LD L,140 | HL=32652 (holding ERIC's distance from the teacher) |
31013 | INC D | D=teacher's y-coordinate + 1 |
31014 | LD BC,2220 | B=8 (NOW DON'T DO IT AGAIN), C=172 (ERIC) |
31017 | CP (HL) | Is ERIC closest to the teacher? |
31018 | JR Z,31028 | Jump if so |
31020 | LD C,166 | On exit from this loop, C will hold 167 (BOY WANDER), 168 (ANGELFACE), or 169 (EINSTEIN) |
31022 | INC C | |
31023 | INC L | |
31024 | INC L | |
31025 | CP (HL) | |
31026 | JR NZ,31022 | |
31028 | LD A,C | A=character number of the kid closest to the teacher |
31029 | CALL 30464 | Give lines to the kid who is closest to the teacher |
31032 | POP HL | Restore the teacher's character number to H |
31033 | RET |