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Routines |
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| 25944 | LD L,0 | Point HL at byte 0 of the character's buffer | ||||||
| 25946 | BIT 0,(HL) | Is the teacher midstride? | ||||||
| 25948 | JR Z,25963 | Jump if not | ||||||
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This entry point is used by the routines at 32379, 61595 and 62794 to make the teacher who his chasing ERIC finish his stride.
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| 25950 | CALL 25012 | Update the SRB for the teacher's current animatory state and location | ||||||
| 25953 | LD B,A | Save the animatory state in B temporarily | ||||||
| 25954 | LD L,15 | Byte 15 holds the y-coordinate adjustment to make as the teacher finishes this stride: 0 normally, 1 if descending a staircase (see later in this routine) | ||||||
| 25956 | LD A,(HL) | |||||||
| 25957 | ADD A,D | Make the appropriate y-coordinate adjustment | ||||||
| 25958 | LD D,A | |||||||
| 25959 | LD A,B | Restore the animatory state to A | ||||||
| 25960 | JP 25600 | Make the teacher finish his stride | ||||||
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The teacher is not midstride. Is he close enough to ERIC to stop the chase?
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| 25963 | CALL 28242 | Is the teacher on a staircase? | ||||||
| 25966 | JR C,26007 | Jump if so | ||||||
| 25968 | LD DE,(53761) | Pick up ERIC's coordinates in DE | ||||||
| 25972 | LD L,0 | Byte 0 holds the teacher's animatory state | ||||||
| 25974 | BIT 7,(HL) | Is the teacher facing left? | ||||||
| 25976 | LD L,1 | |||||||
| 25978 | JR Z,25984 | Jump if so | ||||||
| 25980 | LD A,E | A=ERIC's x-coordinate | ||||||
| 25981 | SUB (HL) | Subtract that of the teacher | ||||||
| 25982 | JR 25986 | |||||||
| 25984 | LD A,(HL) | A=teacher's x-coordinate | ||||||
| 25985 | SUB E | Subtract that of ERIC | ||||||
| 25986 | CP 4 | Is ERIC less than 4 horizontal spaces in front of the teacher? | ||||||
| 25988 | JR NC,26004 | Jump if not | ||||||
| 25990 | INC L | L=2 | ||||||
| 25991 | LD A,(HL) | A=teacher's y-coordinate | ||||||
| 25992 | SUB 4 | |||||||
| 25994 | JR C,25999 | Jump if the teacher's on the top floor | ||||||
| 25996 | CP D | Is ERIC at least 4 vertical spaces above the teacher? | ||||||
| 25997 | JR NC,26004 | Jump if so | ||||||
| 25999 | ADD A,7 | Set the carry flag if ERIC is at least 4 vertical spaces below the teacher | ||||||
| 26001 | CP D | |||||||
| 26002 | CCF | Return if ERIC is within 3 vertical spaces either side of the teacher | ||||||
| 26003 | RET C | |||||||
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The teacher is not close enough to ERIC yet to stop chasing him. Now to figure out the teacher's next move.
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| 26004 | CALL 25534 | D=ERIC's y-coordinate (or the y-coordinate of the floor he's closest to if his feet are not on the floor) | ||||||
| 26007 | CALL 25843 | Work out how the teacher can reach ERIC from here | ||||||
| 26010 | BIT 3,A | Is there a closed door in the way? | ||||||
| 26012 | JP NZ,28834 | Open it if so | ||||||
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There is no closed door in the way. Is the teacher on a staircase?
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| 26015 | LD BC,0 | Initialise the staircase indicator to 0 | ||||||
| 26018 | CP 2 | Is the teacher descending a staircase? | ||||||
| 26020 | JR NZ,26023 | Jump if not | ||||||
| 26022 | INC B | B=1 (teacher is descending a staircase) | ||||||
| 26023 | JR NC,26026 | Jump if the teacher is not ascending a staircase | ||||||
| 26025 | DEC C | C=-1 (teacher is ascending a staircase) | ||||||
| 26026 | CP 3 | Is the teacher on a staircase? | ||||||
| 26028 | JR C,26045 | Jump if so | ||||||
| 26030 | LD L,0 | Byte 0 holds the teacher's animatory state | ||||||
| 26032 | CP 4 | Set the carry flag if the teacher should go left | ||||||
| 26034 | BIT 7,(HL) | Set the zero flag if the teacher is facing left | ||||||
| 26036 | JR C,26043 | Jump if the teacher must go left to reach ERIC | ||||||
| 26038 | JR NZ,26045 | Jump if the teacher is facing right | ||||||
| 26040 | JP 25648 | Turn the teacher round | ||||||
| 26043 | JR NZ,26040 | Turn the teacher round if he's facing right | ||||||
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Now BC is still 0 if the teacher is not on a staircase. Otherwise, B=1 and C=0 if he's descending a staircase, or B=0 and C=-1 if he's ascending a staircase. The value in B is the y-coordinate adjustment to make when the teacher finishes this stride later, and the value in C is the y-coordinate adjustment to make as he goes midstride now.
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| 26045 | LD L,15 | Set byte 15 of teacher's buffer to 1 if the teacher is descending a staircase, or 0 if he's ascending a staircase or not on one | ||||||
| 26047 | LD (HL),B | |||||||
| 26048 | PUSH BC | |||||||
| 26049 | CALL 25012 | Update the SRB for the teacher's current animatory state and location | ||||||
| 26052 | POP BC | |||||||
| 26053 | BIT 0,C | Is the teacher ascending a staircase? | ||||||
| 26055 | JR Z,26058 | Jump if not | ||||||
| 26057 | DEC D | Up a stair as the teacher goes midstride | ||||||
| 26058 | INC A | One foot forward (midstride) | ||||||
| 26059 | JP 24880 | Update the teacher's animatory state and location and update the SRB | ||||||
| Prev: 25940 | Up: Map | Next: 26062 |